the porcupine ray ( urogymnus asperrimus ) is a rare species of stingray in the family dasyatidae .

this bottom-dweller is found throughout the tropical indo-pacific , as well as off west africa .

it favors sand , coral rubble , and seagrass habitats in inshore waters to a depth of 30 m ( 100 ft ) .

a large and heavy-bodied species reaching 1.2 – 1.5 m ( 3.9 – 4.9 ft ) in width , the porcupine ray has a nearly circular , plain-colored pectoral fin disc and a thin tail without any fin folds .

uniquely within its family , it lacks a venomous stinging spine .

however , an adult ray can still defend itself ably with the many large , sharp thorns found over its disc and tail .

the diet of the porcupine ray consists mainly of benthic invertebrates and bony fishes , which it digs up from the sea floor .

it is aplacental viviparous , in which the developing embryos are nourished by histotroph ( " uterine milk " ) produced by the mother .

the porcupine ray has long been valued for its rough and durable skin , which was made into a shagreen leather once used for various utilitarian and ornamental purposes , such as to cover sword hilts and shields .

it is caught incidentally by coastal fisheries .

because it must be handled carefully due to its thorns , its commercial significance is limited .

unregulated fishing has led to this species declining in many parts of its range , and thus has been listed as vulnerable by the international union for conservation of nature ( iucn ) .

porcupine ray

porcupine ray <EOT> it has also been called the roughskin stingaree , rough - skinned ray , solander’s ray and thorny ray .

porcupine ray reaches a maximum length of 4 . 8 feet ( 147 cm ) .

the strange - looking porcupine ray is covered with plate - like tenticles and sharp thorns .

examines wnt3a - porcupine interactions and the importance of fdh - related and other mutations on porcupine activity .

rare porcupine ray ( urogymnus asperrimus ) in marsa alam , egypt . shot on lumix tz10 while snorkelling .

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a porcupine ray , urogymnus asperrimus , in the seychelles . source : olivier cochard - labbé / wikimedia commons . license : cc by attribution - sharealike

porcupine ray populations are declining today , and the species is considered vulnerable to extinction . porcupine rays are not targeted by commercial fisheries , but they are often caught accidently by vessels in nearshore waters . fewer porcupine rays are caught today as bycatch compared to years past , and researchers believe this means the species has been overexploited in its range and there are fewer individuals . further , a porcupine ray’s preferred habitat is in populated coastal areas that are more susceptible to human activity .

determine whether porcupine rays exhibit consistent and predictable patterns when using specific habitats and locations .

a layer of sharp thorns on its back gives this ray a considerable edge over any predators looking for a bite . the spikes , which are a mixture of large , cone - shaped thorns and smaller , pointed scales known as denticles , are critical for the porcupine ray that lacks the venomous barb most stingray species use for warding off larger animals . the porcupine ray is a rarely seen and distinctive ray species that unfortunately faces many threats in its range .

data was obtained through pilot study on ' crowd sourcing ' where divers were asked through different source egg . dive magazine to report sightings of the porcupine ray .

assess how the porcupine ray’s habitat use and movement patterns affect the species’ exposure and sensitivity to impacts , and its potential to adapt to impacts through movement and dispersal .

researchers at the save our seas foundation dárros research centre have a pretty tough time trying to capture a porcupine ray for research purposes . porcupine rays are well camouflaged , as they are a similar colour as the sand - this makes spotting them from the surface a challenge .

rough skin of this ray has been used as leather by many different cultures .

although the porcupine ray urogymnus asperrimus is widespread in the indian ocean and indo - west pacific , it is rare and has declined in at least parts of its range . furthermore , very little is known about the species . by investigating the porcupine ray’s movement patterns and habitat dependencies , this project will contribute to better understanding the species’ vulnerability to habitat degradation and environmental change .

andrew wants to know more about the ‘spiky pancakes’ that are porcupine rays , but to do this , he needs to find them first . armed with underwater cameras , a kayak , and snorkelling and fishing gear he is on a mission to seek out the elusive porcupine ray in the great barrier reef .

reports a click - based technology to visualize palmitoylated forms of wnt proteins in cells , porcupine fatty acid substrate preference , incorporation of fatty acids of different chain lengths by wnts , and s - palmitoylation of human porcupine .

the porcupine ray inhabits coral reefs , preferring sandy , coral rubble and seagrass areas , and is often seen near caves and overhangs ; also near mangroves , in depths to at least 30 m .

the porcupine ray is aptly named for its prickly body that acts as armor against a litany of predators . stingray species are often vulnerable to the appetites of h ammerhead and bull sharks , killer whales and other carnivorous fish . though the porcupine ray has a signature whip - like tail similar to other stingrays , theirs does not hold venom for stunting predators . the porcupine ray ' s body is flattened into an oval - shaped disc with a rounded snout , and is usually shaded brown or grey above and white below . its black tail stands out against its light body , and appears darker towards the tip . the porcupine ray inhabits the indian ocean and the indo - west pacific , concentrating around east africa , the red sea and parts of australia where tropical , inshore waters give way to coral reefs and sandy seafloors .

established the first connection between mutations in porcupine and the x - linked dominant disorder focal dermal hypoplasia ( fdh ) .

information on the undulate ray is currently being researched and written and will appear here shortly . …

brisson ba , bersenas a , etue sm . ultrasonographic diagnosis of septic arthritis secondary to porcupine quill migration in a dog .

provides proof of concept for pharmacological targeting of porcupine by using the small - molecule inhibitor c59 in mouse mammary xenograft models .

describes the identification of a small - molecule inhibitor of porcupine that shows efficacy and is well tolerated in rodent tumor models .

taken as incidental bycatch in trawl nets , tangle nets , and beach seines throughout its range . although occasionally taken in northern australian trawl fisheries , turtle exclusion devices on trawl nets appear to exclude the porcupine ray from capture .

information on the japanese electric ray is currently being written and researched and will appear here shortly . …

information on the caribbean electric ray is currently being researched and written and will appear here shortly . …

information on the golden cownose ray is currently being researched and written and will appear here shortly . …

information on the brazilian cownose ray is currently being researched and written and will appear here shortly . …

little is known about the life history of the porcupine ray . it forages on and around the sea - bed for bottom - dwelling crustaceans , polychaete worms and fish ( 2 ) ( 4 ) . prey is grasped in the ray’s downward - facing jaws , which bear rows of flattened teeth capable of crushing hard , outer shells ( 6 ) . like other stingrays , the porcupine ray probably retains its eggs internally during development , so that once the egg hatch , the female gives birth to a litter of live young ( 6 ) ( 7 ) .

the porcupine ray is found on or near the sea - bed in shallow inshore water , often in association with coral reefs . it commonly occurs over sand or coral rubble substrates , frequently in caves ( 2 ) ( 4 ) .

as discussed in communication , several groups of ray - finned fishes have quite peculiar methods of capturing prey .

johnson md , magnusson kd , shmon cl , et al . porcupine quill injuries in dogs : a retrospective of 296 cases ( 1998–2002 )

© 2018 porcupine musings | a common sense libertarian ( voluntary polycentrist ) perspective on whatever topic i feel particularly compelled to debunk that day .

the porcupine ray has an oval - shaped disc that is covered with plate - like tenticles and sharp thorns . the tail lacks stinging spines and skin folds . the fish is brown to grey above and white below . the tail tip is dark .

the porcupine ray is a really interesting and unusual critter that gets its name from the sharp thorns covering its skin . these rays look something like spiky pancakes , which if you think about it makes a lot of sense . stingrays are really big , flat ‘meat…

information on the fake round ray ( urotrygon simulatrix ) is being researched and written and will appear here shortly . …

the pmnhs is an informal society interested in marine natural history and recording , particularly in the north east atlantic region and the mediterranean sea . the name “porcupine” is taken from the naval survey vessel hms porcupine which was engaged on scientific expeditions in the north east atlantic and mediterranean in 1869 and 1870 .

information on the common shovelnose ray ( glaucostegus typus ) is currently being researched and written and will appear here shortly . …

there are no known conservation measures in place for the porcupine ray ( 1 ) . individuals have , however , been recorded in the nature reserve of the glorieuses islands ( 8 ) , and given this species’ large range , it almost certainly occurs in other protected areas ( 9 ) .

a distinctive but uncommon stingray named for its protective covering of thorns and denticles . the porcupine ray has a thick oval - shaped body with a rounded snout and a long - whip - like tail . unlike other stingrays in the family dasyatidae , there is no venomous barb on the tail .

the flapper skate ( dipturus batis ) is the largest european ray . the undersurface is dark grey with black spots or stripes and the…

ray - finned fishes exhibit quite a variety of mating systems . the four major types , along with a few examples , are :

is the most important means of communication and foraging for many ray - finned fishes . the eyes of fish are very similar to terrestrial

) , combined with pollution and habitat alteration have proven particularly disastrous for groups of endemic ray - finned fishes ( i . e .

the key objective of this research is to document the movement and habitat use patterns of the porcupine ray in coral reef environments and thus determine how the species’ behaviour and habitat use affect its vulnerability to habitat loss and environmental change , and identify potential management responses to reduce impacts and increase the species’ resilience .

very little is known about this mysterious ray , as just ten specimens have been identified and studied in museums . named for the pale margin…

the spotted eagle ray is very distinctive with a flattened body and triangular corners to the wing - like pectoral fins . the snout is rounded…

concepts and terminology , as well as numerous examples from a diverse range of ray - finned fish families . a section of particular interest is

ray - finned fishes inhabit a variety of extreme environments . these include high altitude lakes and streams , desert springs ( e . g .

theiss , s . m . , kyne , p . m . & chisholm , l . a . 2010 . distribution of the porcupine ray urogymnus asperrimus ( bloch & schneider , 1801 ) in australian waters , with new records from queensland . memoirs of the queensland museum - nature 55 : 101 - 105 .

theiss , s . m . , kyne , p . m . and chisholm , l . a . 2010 . distribution of the porcupine ray urogymnus asperrimus ( bloch & schneider , 1801 ) in australian waters , with new records from queensland . memoirs of the queensland museum - nature 55 : 101 - 105 .

the reproductive habits of porcupine rays have rarely been observed , but females most likely retain their eggs internally as most other stingrays do until the eggs are fully developed and then the female can give birth to a live litter . newborn porcupine rays lack the species’ characteristic sharp thorns , but are still equipped with countless denticles on the upper part of the body . porcupine rays forage for bottom - dwelling crustaceans , marine worms and fish that burrow into soft , sandy bottoms . sharp rows of teeth in the ray ' s downward - facing jaws are ideal for breaking the hard , outer shells of its prey . porcupine rays are benthic , which means they live near the sediment surface of the ocean . benthic rays tend to " ripple " their fins to move around above the seafloor , in contrast to pelagic rays that flap their pectoral fins .

ray - finned fishes are essential components of most ecosystems in which they occur . while many ray - finned fishes prey on each other , they can also have significant impacts on nearly all other animals in their habitats . zooplanktivorous fishes , for instance , select for specific types and sizes of

in many ways , the pygmy devilray resembles its larger and more iconic relative , the manta ray . large pectoral fins , fused to the sides of…

ray - finned fishes perceive the external environment in five major ways – vision , mechanoreception , chemoreception , electroreception and magnetic reception , and to humans several of these sensory systems are entirely alien . many types of perception are also used by ray - finned fishes to communicate with individuals of the same (

) , which make up nearly all existing ray - finned fishes , have repeated and extended early trends . many of the sections , such as physical description , reproduction , behavior and ecosystem roles merely scratch the surface , but there are numerous links to family - level ray - finned fish accounts . (

magee aa , ragle ca , howlett mr . use of tenoscopy for management of septic tenosynovitis caused by a penetrating porcupine quill in the synovial sheath surrounding the digital flexor tendons of a horse .

the porcupine ray is widely distributed throughout the indian ocean and the indo - west pacific , occurring from the coast of east africa and the red sea , east as far as marshall islands and fiji , and south as far as northern australia ( 1 ) ( 4 ) . it also occurs in tropical inshore waters of the east atlantic , around central west africa ( 4 ) .

the knifetooth sawfish is an unusual type of ray , with a shark - like body and a distinctive , elongated snout , or rostrum , known as a saw . in…

( wheeler , alwyne 1985 : viii ) . detecting sound in water can be difficult because waves pass through objects of similar density . therefore , ray - finned fishes have

mobulids ( family mobulidae ) , commonly referred to as devil rays , are cartilaginous fishes found circumglobally in tropical , subtropical , and warm temperate waters . these pelagic species exhibit low fecundity and slow maturation ; however , their life history remains poorly understood , yet these species are highly exploited worldwide . this family includes the genus manta and the genus mobula with 11 identified species . five of these species have been confirmed in the philippines , namely : the spine - tail devil ray ( mobula japanica ) , bent - fin devil ray ( mobula thurstoni ) , sickle - fin devil ray ( mobula tarapacana ) , the oceanic manta ray ( manta birostris ) and the reef manta ( manta alfredi ) . two other species the pygmy devilray ( mobula eregoodootenkee ) and the shortfin devil ray ( mobula kuhlii ) are thought to occur in philippine waters though these sightings have not yet been officially confirmed .

many ray - finned fishes exhibit migratory behavior ; daily migrations are usually related to feeding or predator avoidance while longer migrations are usually for reproduction purposes . some fishes stay within saltwater (

and siphonophores ( colonies of organisms , e . g . man - o - war ) , also regularly consume various ray - finned fish . there is even some unlikely predators like

freshwater groups , however , account for the vast majority of actual extinctions in ray - finned fishes . the most significant threats are to families with restricted distribution ( i . e .

, resulting in even more extinctions . the latter example illustrates the complexity of ecological interactions and the fact that ecological interactions are not confined to aquatic organisms . because ray - finned fishes are often important food source to terrestrial organisms ( see below ) , including humans ( see economic importance and conservation ) , changes in ray - finned fish communities can have significant ecological implications .

ray - finned fishes have significant aesthetic , cultural , scientific and transformative value to humans . to many native people , especially in the united states , fish are symbols of cultural tradition and the subject of works of art . snorkeling , scuba diving , and sport fishing are increasingly popular around the world and , of course , ray - finned fishes have significant scientific and educational value .

the porcupine ray is a distinctive and unusual stingray associated with coral reefs . it appears to play an important role in bioturbation and habitat formation in reef lagoons . it is widely distributed from the indian ocean to the indo - west pacific , but relatively rare and very little is known about its biology or ecology . a recent review of the species in australia located only 25 records in museums and scientific databases . the lack of information about the porcupine ray’s biology and ecology is a significant issue given its rarity and the serious threats it faces from habitat degradation and environmental change , especially considering both the documented and projected declines in coral reefs throughout its range . lack of information about the species’ habitat use and movement compromises scientific understanding of its exposure to risks , sensitivity to these risks and ability to adapt to impacts through compensatory behaviours , such as reaching and colonising alternative habitats and locations should coral reefs in one area become degraded . while the species is rare , its highly unusual appearance makes it easy to identify and contributes to its potential role as a charismatic coral reef species . capitalising on these traits , a pilot study was carried out in 2012 using citizen scientists to identify hot spots of porcupine ray distribution . this facilitated the identification of two potential study sites in the great barrier reef . this project will focus on one of these sites , one tree island in the southern great barrier reef .

porcupine’s annual conference and agm takes place over the weekend of saturday / sunday with a two - day conference of talks and posters at plymouth university , followed by a field meeting nearby at wembury on monday [ low tide 0 . 7m @ 12 : 30 ] .

the spiny butterfly ray is under great pressure from fishing in the canary islands , a paradise in the atlantic ocean . david will work with citizen scientists to expand our knowledge about the lives of these vulnerable rays .

, which have greater density than the rest of the fish , in the inner ear attached to sensory hair cells . since gas bubbles increase sensitivity to sound , many ray - finned fish ( e . g .

. while many ray - finned fishes migrate well outside their home range – in many cases hundreds of kilometers , against current and even up waterfalls – they have remarkable abilities to find their way back . for instance ,

another common characteristic of ray - finned fishes is aggressive behavior , which results from competition for valuable resources , such as feeding , refuge and mating territories , mates , eggs , and young . one form of aggressive behavior is

not surprisingly , the lifespan of ray - finned fishes varies widely . in general , smaller fish have shorter lives and vice versa . for instance , many smaller species live for only a year or less , such as north american

wnt proteins are critical regulators of signaling networks during embryonic development and in adult tissue homeostasis . the generation of active wnt proteins requires their regulated secretion into the extracellular space . once secreted , wnts signal through the cell surface via receptor binding on wnt - receiving cells , a mechanism that is prevalent in stem cell and cancer biology . important to both wnt secretion and receptor recognition is their post - translational fatty acylation . in this perspective , we highlight progress in elucidating the biochemistry of wnt fatty acylation and provide a molecular view on the enzymology of substrate recognition and catalysis , with a focus on the wnt o - acyltransferase porcupine . special emphasis is given to wnt fatty acid biosynthesis , wnt - porcupine interactions , clinical mutations of porcupine and emerging therapeutics for perturbing wnt fatty acylation in cancer . finally , we discuss models for the functional role of the unsaturated fatty acyl chain in mediating lipid - protein interactions and in wnt trafficking .

although very wide ranging , this ray appears to be uncommon compared to various species of dasyatid rays which are sympatric with it . occurrence appears to be patchy with localised hotspots ( chin 2014 ) . juveniles appear to be site - attached , and highly resident to small areas of shallow coastal mud and mangrove habitats ( cerutti - pereyra et al . 2014 ) . it has been recorded from coral reefs , sandy reef lagoons , beaches , mud flats and mangroves , at depths of ~ 1 m to at least 30 m ( o ' shea 2013 , cerutti - pereyra et al . 2014 , chin 2014 ) . there is virtually no information available on life history parameters for this species . age at maturity , longevity , average reproductive age , generation time and average annual fecundity are all unknown . attempts to collect size - at - age data from vertebral counts have proved difficult due to the fragile nature of vertebra ( o ' shea 2013 ) . the porcupine ray reaches a maximum size of at least 115 cm disc width ( dw ) with females mature by ~ 100 cm dw and males at ~ 90 cm dw ( last and stevens 2009 ) . using data from the brown stingray ( dasyatis lata ) , a related species of similar size from the pacific as a proxy , generation time for the porcupine ray is inferred to be 21 . 5 years .

despite its large range , the porcupine fish is not regularly recorded by fisheries surveys , and is therefore believed to have a relatively small population . the population data that is available for this species indicates that it has undergone a significant population decline in parts of the centre of its range ( 1 ) . the reason for this is unclear , as while the meat , skin and cartilage all have commercial value , the porcupine fish typically has little or no importance to fisheries . it is , however , often caught as bycatch in trawls and beach seines , which may be having a detrimental effect on its population . ( 2 ) ( 4 ) .

a 17 - month - old holstein heifer was presented for persistent enlargement above the right hind fetlock of 1 - month’s duration . diffuse plantar soft tissue swelling was present on the radiographs and ultrasonography revealed the presence of multiple porcupine quill extremities embedded in the subcutaneous tissue within the flexor tendon sheath wall . surgical removal was performed .

porcupine representations of the different eigenvectors derived from the md simulations demonstrated less evidence of long range concerted motions . moreover , porcupine analysis of intermediate subtrajectories ( 3 - 15 ns , 6 - 15 ns , 9 - 15 ns , 3 - 12 ns ) showed little mutual similarity . taken together , these results suggest that the modes of motion generated by analysis of concoord ensembles might emerge on a time scale that is longer than that of our simulation . interestingly , however , in an analysis of the full 15 - ns trajectory of au , a motion resembling eigenvector 1 of the concoord ensemble appeared as eigenvector 3 ( fig . 2 c ) .

. in this situation , smaller males attempt to ' sneak ' fertilize the eggs of females as peak spawning is occurring ; the smaller males release gametes simultaneously in the vicinity of the spawning pair . hermaphroditism in ray - finned fishes involves individuals containing ovarian and testicular tissue (

species , which grow primarily in the sea but return to aquatic areas before they , spreading nutrients from the ocean up and down rivers . during rainy periods in tropical watersheds , ray - finned fish forage in flooded areas , consuming seeds and dispersing them throughout the floodplain .

little is known about the population status , trends or structure of this species , although the porcupine ray is considered to be an uncommon species . globally , shark and ray landings have declined by at least 20 % since 2003 , but the indo - pacific is amongst the regions where this decline has been more severe ( dulvy et al . 2014 ) . catches of sharks and rays in southeast asia are very high but are declining and fishers are travelling much further from port in order to increase catches ( chen 1996 ) . net and trawl fisheries in indonesia ( especially the java sea ) and elsewhere are very extensive and as a result , many shark and ray species are highly exploited and stocks of most species have declined by at least an order of magnitude ( blaber et al . 2009 ) . batoids are heavily exploited ( white and dharmadi 2007 ) and datasets from as early as 1963–1972 show the considerable decline in batoids in the gulf of thailand ( pauly 1979 ) . trawl and gill net fisheries are also moving further afield . for example , in jakarta the gillnet fishery at muara baru travels to waters around kalimantan due to the decline in local populations ( w . t . white , unpubl . data ) . while species - specific data on long - term declines in elasmobranchs in the southeast asian region are lacking , declines of he porcupine ray in southeast asia and elsewhere in the indo - west pacific are inferred given the widespread historical and continuing declines of demersal fisheries in this region ( stobutzki et al . 2006 ) . furthermore , the extensive loss and degradation of habitats such as coastal mangroves are another key threat to coastal and inshore species ; southeast asia has seen an estimated 30 % reduction in mangrove area since 1980 ( fao 2007 , polidoro et al . 2010 ) .

) have modified gas bladders and swimbladders adjacent to the inner ear . most ray - finned fishes have keen hearing ability and sound production is common but not universal . in groups that do utilize sound for communication , the most common purpose is territorial defense ( e . g .

) . at this point , approximately 90 species of ray - finned fishes are known to be extinct or only survive in aquaria , 279 are critically endangered or endangered , and another 506 are listed as vulnerable or near threatened . families of particular concern ( in descending order ) are

one of our primary research sites has been the monitoring of a century - old ray fishery site in bohol , with the goal of understanding the reproductive biology of the devil rays to assess the sustainability of the fishery . our team has been working with the local fishing community since 2012 .

justification : the porcupine ray ( urogymnus asperrimus ) is a shallow water species occurring inshore to at least 30 m depth , often associated with sandy and coral reef habitats . this species is widespread in the indo - west pacific region where intensive and largely unmanaged net and trawl fisheries occur ( with the exception of australia ) . while life history data are not available , the life history of a related species , the brown stingray ( dasyatis lata ) , suggests that this species may have a long generation length ( 21 . 5 years ) . fishing pressure is heavy in its known , shallow - water habitat , and fisheries are likely to catch this species if present . many shark and ray fisheries and stocks in the region are known to be over - exploited , with catches declining . market surveys indicate that this species has decreased in abundance in parts of the centre of its range for which comparative data are available such as the gulf of thailand . it is also a commonly caught and heavily used species in indonesia which is a global centre for intense shark and ray fishing and over - exploitation . based on its shallow water habitat preferences , long estimated generation time , global declines in chondrichthyan landings of at least 20 % over the past 12 years , and the fact that the indo - west pacific region is a region with some of the most poorly managed and intensely fished waters , a population reduction of greater than 30 % over three generations is inferred for the porcupine ray , resulting in an assessment of vulnerable . in australia , the species is assessed as least concern as has no commercial value in australian waters and is seldom caught . while the species was occasionally captured in commercial trawl fisheries , the introduction of trawl exclusion devices has significantly decreased the bycatch of large batoids in australian trawl fisheries . marine protected areas at ningaloo reef and the great barrier reef are likely to provide effective protection for this species .

during courtship ray - finned fishes exhibit a wide range of complex behaviors , reflecting their evolutionary heritage and the particular environments they inhabit . for instance , pelagic spawners tend to have more elaborate courtship rituals than benthic spawners . some of the behaviors include sound production , nest building , rapid swimming patterns , the formation of large schools , and many others . in addition , ray - finned fishes frequently change color at specific points in their reproductive cycle , either intensifying or darkening depending on the species , release pheromones , or grow tubercles ( tiny bumps of keratin ) on the fins , head or body .

clearly ray - finned fishes display considerable complexity in their ability to perceive their environment and communicate with other individuals , yet until recently it was assumed that fish had negligible cognitive ability . current research , however , indicates that learning and memory are integral parts of fish development and rely on processes very similar to those of terrestrial

some species of stingrays have evolved the amazing ability to crush and consume hard - shelled marine critters like clams , scallops , oysters and snails . these durophagous ( meaning ‘hard - eating’ ) stingrays can be found in subtropical to temperate waters worldwide , and they include the cownose and eagle rays . unfortunately , because their diets occasionally include economically valuable shellfish , durophagous stingrays are often considered ‘pest’ species by fishermen . this has led to the development of uncontrolled kill tournaments for these rays and advertising campaigns to increase ray consumption ( such as , ‘save the bay , eat a ray’ ) despite these species having some of the lowest reproductive rates among marine fishes .

benthic ray - finned fishes also utilize numerous methods of camouflage ( for both hunting and predator avoidance ) . a common and elaborate method in tropical seas is mimicking the background of the habitat ( protective resemblance ) , which involves variable color patterns as well as peculiar growths of the skin that may resemble pieces of dead vegetation ,

in 2015 lamave started a collaborative project with the tubbataha reefs natural park to assess the abundance and diversity of rays within the park . using bruv systems and visual identification a number of different species have been reported in the park including : porcupine , marble , cowtail , whiptail , mobula and manta rays . recently we started a tagging project , using acoustic tags to determine the local movements of reef mantas around the atolls .

consume the scales of the dead fish as they sink . ray - finned fishes also have significant impacts on a variety of plant species . the trophic cascade example ( above ) illustrated an indirect connection between microscopic plants ( phytoplankton ) and fish , but fish also excrete soluble nutrients into the water , such as phosphorus . phosphorus is essential for phytoplankton growth , and fish secretions may provide significant amounts of nutrients in some lakes . a more direct connection is simply the consumption of numerous plant species ( see food habits ) . finally , fish may significantly alter the geological dynamics of their habitats . many ray - finned fish build nests or burrows ( e . g . several

ap— the x - ray structure determined for phosphorylated cdk2 , bound to cyclin a ( pdb accession id : 1jst ) was reduced to a single dimer with associated atp and water of crystallization , as for iu . in this case a metal ion , manganese , was already in place . for the simulation the manganese was replaced with a magnesium 2 + ion in the same location .

a 17 - month - old heifer was referred to the veterinary hospital for a persistent enlarged flexor tendon sheath on the right hind limb of 1 - month’s duration . the anamnesis revealed the heifer had been injured by porcupine quills in this area 1 mo ago . quills were removed by the owner several hours after the initial injury and penicillin procaine ( depocillin ; intervet canada , whitby , ontario ) , 20 000 iu / kg body weight ( bw ) , im was administered for 5 d .

dynamic modes— fig . 2 a shows , in porcupine representation , the most significant motion of the cdk2 - cyclin a complex predicted by concoord for the ap state : a twist about an axis that runs from the cdk2 to cyclin a , pivoting approximately about residue p155 . however this gross twisting motion of the cdk2 - cyclin a dimer masks a flexing motion of the cdk2 . we can isolate the dynamics of the cdk2 within the complex by considering only cdk2 atoms in the pca analysis of the dimer .

based on feeding habits , researchers broadly classify ray - finned fishes as herbivores , carnivores , omnivores , zooplanktivores and detrivores . there is considerable nuance within each of these categories because many fish are opportunistic feeders – they tend to consume whatever is around , especially when food is scarce . however , primary feeding habits are often associated with body form , mouth type and digestive apparatus , as well as teeth . for instance ,

the porcupine ray is a highly distinctive , but little known species , which is named for the unusual thorny projections that are found on the upperside of its body ( 4 ) ( 5 ) . this species has a thick , oval , disc - shaped body , a rounded snout and a long , whip - like tail , which does not possess the venomous barb that is characteristic of most members of the stingray family ( dasyatidae ) ( 2 ) . instead , this species is protected from predators by its armoured body , which is covered with a mixture of large , sharp , conical thorns and smaller , pointed projections known as “denticles” . the young lack the thorns , but bear numerous large , flat denticles on the upper surface of the body ( 2 ) ( 5 ) . the colouration of this species is brown to light grey above and white below , while the tail is blackish , becoming darker towards the tip ( 2 ) ( 5 ) .

in this report we use a two letter code to identify a cdk2 - cyclin a structure in a given state of phosphorylation and activity as in table i . according to this nomenclature therefore , ap ( for active form , phosphorylated ) corresponds to the x - ray structure for thr 160 phosphorylated ( and therefore active ) cdk2 - cyclin a with the phosphate group intact . au ( for active structure , manually edited so as to be unphosphorylated ) is the same structure with the phosphate group removed in silico . likewise iu ( for inactive form , unphosphorylated ) corresponds to the x - ray structure for unphosphorylated ( and therefore inactive ) cdk2 - cyclin a with no addition of phosphate group , and ip ( for inactive structure , manually edited so as to be phosphorylated ) is the same structure with a phosphate group added in silico to thr 160 before simulation . the four starting configurations were prepared as follows .

for the peak at residue 11 , this is consistent with the proposed biological function of this loop : it opens and closes to allow entrance and exit of atp and adp respectively . the second loop at around residue 35 is often difficult to model in x - ray structures of both monomeric cdk2 and cdk2 in complex with cyclin a , and may play a role at the edge of the interface between the pstaire helix and the cdk - proximal domain of cyclin a .

differential roles for the cluster of arginines that bind phospho - thr 160 — as discussed above , examination of the x - ray structure of phosphorylated cdk2 shows that the negatively charged phosphate group on phospho - thr 160 is docked into a triad of positive arginines : arg 50 , arg 126 , and arg 150 . the natural interpretation is that there is a coulomb attraction between these entities , which anchors the phospho - thr 160 in place and maintains the functional phosphorylated configuration .

the species is presumably largely taken as bycatch in unregulated fisheries in nearshore waters . it has been recorded as a high value catch in indonesian net fisheries ( white et al . 2006 ) . it appears to have disappeared or become extremely rare ( compared to certain other batoids ) in the batoid catches landed in bangkok from the gulf of thailand in recent decades ( compagno and cook , unpubl . data ) . this suggests probable local over - exploitation here and possibly also in the bay of bengal . similar trends are likely to be occurring or will occur in other areas where batoids are taken in multi - species fisheries . certainly , demersal fishery resources in the gulf of thailand and southeast asia have been severely depleted from historical levels ( stobutzki et al . 2006 ) . human modification and degradation of the ray ' s habitat is also possibly occurring in some of the more highly populated and polluted coastal areas as a result of human influences . the loss of coastal habitats such as mangroves may be of particular concern for this species which is suspected to have highly localized habitat use ( a . chin , unpubl . data ) . this species was occasionally taken in northern australian trawl fisheries ( brewer et al . 2006 ) . however , the introduction of turtle exclusion devices appears to have successfully excluded this species from continuing capture in trawl nets ( brewer et al . 2006 ) . the porcupine ray is considered to be potentially one of the most vulnerable chondrichthyans to the impacts of climate change in northern australia ( chin et al . 2010 ) .

fishes are obviously of enormous economic import to humans . primarily , humans consume fish through fishing and aquaculture , and fish are an essential form of protein for millions of people around the world . the farmed salmon industry alone is valued at over 2 billion dollars a year , but unfortunately , aquaculture operations can have serious ecological consequences . similarly , ray - finned fishes are quite popular in the aquarium trade , and those with high cash value , such as many tropical fishes , are removed in highly damaging ( i . e . using poisons ) and exploitive ways ( see conservation and other comments ) . televised sport fishing events are also popular on rivers , lakes , coastal areas and reefs around the world . the fast - growing scuba industry relies heavily on thriving coral reefs with diverse and abundant communities of ray - finned fishes . finally , of less direct ( and severely underappreciated ) economic importance are the ecological roles that fishes fill , like controlling insect populations ( e . g . many still - water groups like

three specimens of the porcupine ray urogymnus asperrimus ( bloch & schneider , 1801 ) are reported from heron island on the great barrier reef , qld . these are the first records from the southern great barrier reef and represent the southernmost records for this species on the east coast of australia . an immature male with a disc width ( dw ) of 650 mm and two females measuring 620 mm dw and 545 mm dw were caught on the eastern side of the island using hand or seine nets . the two females were released alive after examination . some morphometric data from two of the individuals are provided . the distribution , biology and ecology of this species are poorly - known , with only five catalogued australian specimens held in australian museums . the majority of these are not whole specimens and are in poor condition . there is further scattered information from photographs and live sightings . all known australian records of u . asperrimus are summarised here . there are records of the species across tropical northern australia , from ningaloo reef , wa ( 22 [ degree ] 43 [ minute ] s ) to heron island , qld ( 23 [ degree ] 26 [ minute ] s ) .

the porcupine ray is a widely distributed but relatively uncommon species found in the indo - west pacific ; it is also possibly tropical west africa ( senegal , guinea , ivory coast ) and as an invasive in the eastern mediterranean ( via the suez canal ) ( last and stevens 2009 ) . localities include south africa , madagascar , kenya , seychelles , red sea ( koseir ) , saudi arabia , oman ( muscat ) , gulf of oman , arabian sea and persian gulf , pakistan , india ( bombay , madras , malpe , south canara on malabar coast ) , sri lanka , myanmar , malaysia ( malay peninsula , penang ) , singapore , taiwan , thailand , indonesia ( jakarta , java , kalimantan ) , possibly the philippines , viet nam ( cholon ) , australia ( queensland , western australia , northern territory ) , new guinea and melanesia ( fowler 1941 , herre 1953 , capape and desoutter 1990 , last and stevens 1994 , last and compagno 1999 , theiss et al . 2010 , ebert et al . 2013 ) . the species appears to have patchy localized distributions with local hotspots recorded at d ' arros island in the seychelles , and specific sites in ningaloo reef and the great barrier reef , australia ( theiss et al . 2010 , chin 2014 ) .

actinopterygians , or ‘ray - finned fishes , ’ are the largest and most successful group of fishes and make up half of all living vertebrates . while actinopterygians appeared in the fossil record during the devonian period , between 400 - 350 million years ago ( ma ) , it was not until the carboniferous period ( 360 ma ) that they had become dominant in freshwaters and started to invade the seas . at present , approximately 42 orders , 431 families , and nearly 24 , 000 species are recognized within this class but there are bound to be taxonomic revisions as research progresses .

key to interpreting these eigenvectors is a helpful visualization of them . we have based our visualizations on the porcupine plots of ( 30 ) . in that study , a stick was drawn for all residues corresponding to the movement implied for that residue for a given eigenvector . for example to visualize eigenvector 1 a stick is drawn for each residue starting from the cα and projecting in the direction of the component of the first eigenvector that corresponds to that residue . we have found that cones are easier for the eye to interpret than sticks and a script was written to allow the molecular graphics program vmd ( 32 ) to automatically plot these cones onto the protein , given the eigenvectors of the pca decomposition . 2 we have described elsewhere ( 29 ) a web - service 3 in which we have made these analyses and visualizations available to other researchers .

) . the key to electrical communication is not simply the ability to detect electrical fields , but to produce a mild electrical discharge and modify the amplitude , frequency , and pulse length of the signal . this makes electrical signals individually specific , in addition to being sex and species - specific . consequently , “electrical discharges can have all the functions that visual and auditory signals have in other fishes , including courtship , agonistic behavior and individual recognition” ( moyle and cech 2004 : 206 ) . finally , a few highly migratory ray - finned fishes can apparently detect earth - strength magnetic fields directly , in much the same way sensation occurs with the lateral line . while the specific mechanisms of

our results show that the charge on the phosphate accounts for much , but not all of the tendency of the phospho - thr 160 not to unfold from its active conformation . however , the full 2 - charge is not required for this effect over the timescales considered : little difference is observed in simulations where the phosphate is given a single negative charge . as expected , removal of the phosphate from a simulation of the phosphorylated x - ray structure leads to a significant loosening of the association between the arginine triad ( arg 50 , arg 126 , and arg 150 ) and thr 160 . indeed , in one simulation , a rapid partial unfolding of the t - loop was observed .

ray - finned fishes generally avoid predators in two ways , through behavioral adaptation and physical structures , such as spines , camouflage and scents . usually , several behavioral and structural tactics are integrated because it is advantageous for fishes to break the predation cycle ( 1 - 4 ) in as many places as possible , and the earlier the better . for instance , ( 1 ) the primary goal of most fish is to avoid detection , or avoid being exposed during certain times of the day . if detected , ( 2 ) a fish might try to hide very quickly , blend in with the surroundings , or school ; ( 3 ) if the fish is about to be attacked then it must try to deflect the attack , and if attack is unavoidable ( 4 ) the fish will try to avoid being handled and possibly escape . therefore , many fishes avoid even the chance of attack through particular cycles of activity , shading ( or lighting , see below ) and camouflage , mimicking , and warning coloration .

( including chemoreception , electroreception , magnetic reception and a “distance - touch” sensation – see communication ) , and some even produce their own light or electricity . in addition , color diversity in ray - finned fishes is “essentially unlimited , ranging from uniformly dark black or red in many deepsea forms , to silvery in pelagic and water - column fishes , to countershaded in nearshore fishes of most littoral [ near - shore ] communities , to the strikingly contrasted colors of tropical freshwater and marine fishes” ( helfman et al . 1997 : 367 ) . of course , extravagant coloration is not helpful for fish at risk of being eaten , yet bright coloration is environment - specific ( see helfman et al . 1997 : 367 ) and bright colors at one depth are cryptic at others due to light attenuation ( see communication ) . further , color change is common in brightly colored ( as well as many other ) fishes and occurs under a variety of circumstances . pigments are responsible for a many types of color change , but there are also

monomeric cdk2 has negligible activity because the residues that should form its catalytic and substrate - recognition sites are disordered ( 3 ) . full activation requires both binding by cyclin a or cyclin e and phosphorylation of residue thr 160 on a loop ( the “t - loop” ) by a cdk - activating kinase ( cak ) activity ( 4 – 6 ) . the structure of cyclin a ( 7 ) does not change significantly , but many of the cdk2 residues are realigned toward their active configuration ( 8 ) . in this state the cdk2 has 0 . 4 % of its full activity : 100 % activity is achieved when thr 160 is phosphorylated ( 9 ) . x - ray structural data shows that phosphorylated thr 160 turns in to contact three arginine residues ( arg 50 , arg 126 , arg 150 ) , twisting the t - loop and stabilizing the conformation of residues linked to the catalytic apparatus of the kinase ( 6 ) . fig . 1 shows the experimentally determined structures of phosphorylated and unphosphorylated cdk2 in complex with cyclin a , emphasizing the arginines and the phosphorylated threonine .

principal dynamic modes of the cdk2 - cyclin a dimer . a , porcupine plot of principal motion of the dimer calculated using concoord . the view is from cdk2 along the cdk2 - cyclin a axis . the motion is primarily an interdomain twist . b , same motion recast to show only motions internal to the cdk2 . the motion is seen to be a relative flexing of the n - and c - terminal domains causing the active site to open and close . c , similar motion is sometimes observed in a corresponding analysis of a subset of the trajectories generated by molecular dynamics , although in this case it appears as the 3rd ranked eigenvector . d , when an ensemble of structures taken from the pdb of cdk2 bound to a range of ligands is subjected to the same analysis the result obtained is similar to that of the concoord ensemble : the dominant mode is shown here . e , relative contributions of different modes ( eigenvectors ) to the overall motion is shown for the three analyses : concoord ( short dashed line ) , md ( long dashed line ) , and experimental ensemble ( solid line ) . the data are renormalized so that the eigenvalues for each set add up to unity . f , second most significant motion for cdk2 is a relative twist of the n - and c - terminal domains . this view is looking “down” from the n - terminal domain , and was generated from the concoord ensemble .


the dunlin ( calidris alpina ) is a small wader , sometimes separated with the other " stints " in erolia .

the english name is a dialect form of " dunling " , first recorded in 1531 – 2 .

it derives from " dun " , " dull brown " , with the - ling suffix meaning " concerned with " .

the genus name is from ancient greek kalidris or skalidris , a term used by aristotle for some grey-coloured waterside birds .

the specific alpina is from latin and means " of high mountains " , in this case referring to the alps .

it is a circumpolar breeder in arctic or subarctic regions .

birds that breed in northern europe and asia are long-distance migrants , wintering south to africa , southeast asia and the middle east .

birds that breed in alaska and the canadian arctic migrate short distances to the pacific and atlantic coasts of north america , although those nesting in northern alaska overwinter in asia .

many dunlins winter along the iberian south coast .

dunlin

dunlin <EOT> black - breast , black - breast dunlin , purre , red - backed sandpiper .

the dunlin is a very rare vagrant to new zealand , with four accepted records .

marthinsen g , wennerberg l . lifjeld jt . phylogeography and subspecies taxonomy of dunlin (

roberts , g . ( 1983 ) . a sighting of dunlin calidris alpina in north queensland and a review of australian dunlin records . sunbird . 13 : 15 - 19 .

seasonal variation in harvestable density and biomass of main dunlin prey species in winter and spring .

table 1 : the development of the population of the dunlin in denmark 1964 - 2011 .

equations used to calculate biomass ( ash free dry weight , afdw ) of dunlin invertebrate prey .

rather cold tolerant for a shorebird , dunlin winter well to the north along the atlantic coast .

population development of baltic bird species : southern dunlin ( calidris alpina schinzii l . , 1758 )

one weird observation regarding the dunlin is their close association with the golden plover , there are several accounts of a single dunlin joining a flock of plover or even accompanying single plovers on feeding forays .

( 5 ) dunlin x purple sandpiper ( calidris alpina x calidris maritima ) . see millington 1994 .

the dunlin is classified as least concern ( lc ) on the iucn red list ( 1 ) .

habraken , a . 1980 . a dunlin at karaka shellbanks . notornis 27 : 300 - 301 .

wennerberg l , holmgren nma , jönsson pe . von schantz tv . genetic and morphological variation in dunlin

figure 1 : the breeding population of the southern dunlin in mecklenburg - western pomerania 1970 - 2011 .

brown , b . 1979 . dunlin in the firth of thames . notornis 26 : 202 - 203 .

kelsey , m . , m . hassall . 1989 . patch selection by dunlin on a heterogeneous mudflat .

the dunlin nests on the tundra and winters on beaches , river and lake shores , mudflats and sandflats .

) . five subspecies of dunlin breed in the east asia and alaska region known as beringia ( fig .

as will be discussed below , the most parsimonious combinations seems to be dunlin x white - rumped sandpiper but it is worth keep other possibilities in mind such as dunlin x western sandpiper or white - rumped x western sandpiper .

diet of dunlin in winter and spring assessed by ( a ) field observations and ( b ) dropping analyses .

the dunlin has rapid , low flight when flushed . larger flocks twist and turn in unison while flying together .

dunlin . overwintering bird moulting into breeding plumage . manukau harbour , april 2006 . image © phil battley by phil battley

outside the breeding season , dunlin are typically found in the company of other waders , on muddy estuaries and coastlines .

brown , b . 1975 . sight record of a dunlin in new zealand . notornis 22 : 241 - 243 .

we collected 370 dunlin blood or tissue samples from 18 breeding areas during the 2003 to 2009 breeding seasons ( fig .

audubon ( 2005 ) . dunlin calidris alpina . conservation status . viewed 2 may 2008 . available from : urltoken .

dunlin breeding in northern alaska apparently move west , migrating down the eastern side of siberia and asia to japan and china .

dunlin mainly eat small invertebrates ( worms , crustaceans , molluscs and insects ) obtained by probing . no new zealand data .

baker , m . 1982 . individuality of vocalizations in dunlin : a possible acoustic basis for recognition of parent by offspring .

shepherd , p . , d . lank . 2004 . marine and agricultural habitat preferences of dunlin wintering in british columbia .

] than the dunlin in greenland ! ) the first observations listed for svalbard often come from adventfjorden , e . g .

( 4 ) dunlin x white - rumped sandpiper ( calidris alpina x calidris fuscicollis ) . see mclaughlin and wormington 2000 for discussion .

the oldest recorded dunlin was at least 12 years , 5 months old when it was recaptured and rereleased during banding operations in california .

the dunlin eats insects and larvae , marine worms , small crustaceans , snails and small fish . sometimes the dunlin is called the " sewing machine " because of the way it bobs its head up and down and pokes into the ground when it probes for food .

dunlin : rock sandpiper has less black on belly and has yellow legs . purple sandpiper is darker gray above and has yellow legs .

clark na ( 1983 ) the ecology of dunlin ( calidris alpina l . ) wintering on the severn estuary : university of edinburgh .

the feeding strategy of the dunlin ( calidris alpina l . ) in artificial and non - artificial habitats at ria de aveiro , portugal

the pilothouse version of the dunlin 22 is available as downloadable study and construction plans , and printed construction . imperial and metric units .

the dunlin eats insects and larvae , marine worms , small crustaceans , snails , and small fish . the dunlin is sometimes called the " sewing machine " because of the way it bobs its head up and down and pokes into the ground as it probes for food .

a conservation priority for the dunlin is the development of monitoring across its range so that overall population trends may be determined ( 2 ) .

the female dunlin lays four eggs . the chicks hatch in 21 - 22 days and fledge when they are 19 - 21 days old .

there is a report of a dunlin at the same site on 6th february 1979 , when the pond was then concrete - lined and called the model yacht pond , and the following year i observed a dunlin that was present by alexandra lake from 31st august to 3rd september .

clark , n . a . ( 1987 ) . a probable hybrid dunlin / sanderling . scottish birds . 14 : 211 - 213 .

sterbetz , i . ( 1992 ) . foods of dunlin ( calidris alpina ) in hungary . aquila . 99 : 49 - 57 .

embed this arkive thumbnail link ( " portlet " ) by copying and pasting the code below . < a href = " urltoken " title = " arkive species - dunlin ( calidris alpina ) " > < img src = " urltoken " alt = " arkive species - dunlin ( calidris alpina ) " title = " arkive species - dunlin ( calidris alpina ) " border = " 0 " / > < / a >

saunders , g . c . 2012 . dunlin . in miskelly , c . m . ( ed . ) new zealand birds online . urltoken

stockholm 350xx12 , migrant 2c male , ljunghusen , 2 . 7 . 05 . sometimes the dunlin male ( in this case belonging to the subspecies

) are plausible hypotheses that may explain differences between data sets . however , adult male dunlin usually exhibit higher breeding site fidelity relative to females ( soikkeli

gromadzka , j . ( 1989 ) . breeding and wintering areas of dunlin migrating through southern baltic . ornis scandinavica . 20 : 132 - 144 .

similar species : the bane of twitchers ; dunlin can be , and has been , confused with almost every other small wader , from least sandpiper to curlew sandpiper . the black belly in breeding plumage is diagnostic . in non - breeding plumage the longer bill is sufficient to distinguish dunlin from stints . the significantly shorter legs should be sufficient to distinguish dunlin from curlew sandpiper ( individuals of the subspecies pacifica are almost the same size as , and have a bill of similar length to , curlew sandpiper . ) dunlin also appears horizontal when feeding and roosting ; in contrast to the more upright curlew sandpiper . the similar - sized white - rumped and baird’s sandpipers have wings that extend beyond the tail . the former , with which dunlin has been known to interbreed , has a white rump . in non - breeding plumage dunlin is darker than sanderling , with less white in the wings , and has a longer bill .

the dunlin is a medium sized shore bird about seven to eight inches in length . it has a long , dark bill with a little downward dip at the end . it has a black patch on its belly and black legs . its back and wings are reddish - brown and its head and chest are white with brownish specks . in the winter the dunlin is a grayish color . the dunlin used to be known as the red - backed sandpiper .

the dunlin is one of the world’s most abundant waders , with an estimated population between 4 , 600 , 000 and 6 , 500 , 000 birds .

the dunlin is a medium , rather stocky shorebird with a black patch on the belly and a long , decurved bill . breeding birds are reddish above .

) . in contrast to past genetic studies of dunlin that included limited sampling of beringia - associated subspecies ( e . g . , wenink et al .

the dunlin is a conventionally accepted species ( christidis & boles 2008 ; cramp & simmons 1983 ; sibley & monroe 1990 ) . there are nine subspecies :

. this bird is east siberian or alaskan , a true " red - back " - holmes ' nickname for alaskan dunlin . cf . right side of

the dunlin is a medium - sized shore bird about 7 to 8 inches in length . it has a long , dark bill with a little downward dip at the end . it has a black patch on its belly and black legs . its back and wings are reddish - brown , and its head and chest are white with brownish specks . in the winter , the dunlin is a grayish color . the dunlin used to be known as the red - backed sandpiper .

wenink pw , baker aj . tilanus mgj . hypervariable - control - region sequences reveal global population structuring in a long - distance migrant shorebird : the dunlin (

erritzoe , j . ( 1994 ) . first record of the dunlin from the philippines . bulletin of the british ornithologists club . 114 : 128 - 129 .

greenwood , j . g . ( 1983 ) . dunlin calitris alpina in south america . bulletin of the british ornithologists club . 103 : 110 - 111 .

worrall , d . h . ( 1984 ) . diet of the dunlin calidris alpina in the severn estuary . bird study . 31 : 203 - 212 .

soikkeli , m . ( 1964 ) : the distribution of the southern dunlin ( calidris alpina schinzii ) in finland . ornis fennica 41 : 13 - 21 .

embed this arkive thumbnail link ( " portlet " ) by copying and pasting the code below . < a href = " urltoken " title = " arkive video - dunlin nest being raided by hedgehog , chicks already hatched " > < img src = " urltoken " alt = " arkive video - dunlin nest being raided by hedgehog , chicks already hatched " title = " arkive video - dunlin nest being raided by hedgehog , chicks already hatched " border = " 0 " / > < / a >

the microsatellite analyses provided varying insights regarding genetic differentiation patterns in dunlin . structure suggested no evidence of differentiation among subspecies . although the greatest average likelihood score was observed for the

hill bl . 2012 . fairbanks , ak university of alaska fairbanks factors affecting survival of arctic - breeding dunlin ( calidris alpina arcticola ) adults and chicks . ms thesis .

kelsey , m . g . & m . hassall ( 1989 ) . patch selection by dunlin on a heterogeneous mudflat . ornis scandinavica . 20 : 250 - 254 .

conservation plan for dunlin with breeding populations in north america ( calidris alpina arcticola , c . a . pacifica and c . a . hudsonia ) , version 1 . 0 .

wenink pw , baker aj . tilanus mgj . mitochondrial control - region sequences in two shorebird species , the turnstone and the dunlin , and their utility in population genetic studies .

mclaughlin , k . a . & a . wormington ( 2000 ) . an apparent dunlin × white - rumped sandpiper hybrid . ontario birds . 18 : 8 - 12 .

this is the vanishing meadow dunlin , the one the danes call " engsryle " ( " y " like in cylinder ; the word " ryle " must be onomatopoetic ) .

walking from home across the flats to enjoy a coffee in the sun in the cemetery ( ! ) , my ' phone rang . . . " there ' s a dunlin on the jubilee pond " said jonathan lethbridge , so instead of a short walk and sit in the sun , i had a long walk and an excellent view of a dunlin .

the 2000 study showed that in south uist and benbecula , numbers of breeding snipe , dunlin and ringed plover fell by 60 % , redshank declined by 40 % and lapwing by 30 % . this contrasted with an increase in lapwing and redshank numbers on north uist and although dunlin declined by 30 % here , it was half the decline in the south .

blomqvist , d . , o . johansson , u . unger , m . larsson , l . flodin . 1997 . male aerial displayand reversed sexual size dimorphism in the dunlin .

there are nine different subspecies of the dunlin ( cramp & simmons 1983 ) , and though these breed separately , there is much intermingling on passage and in non - breeding areas .

wennerberg , l . ( 2001 ) . breeding origin and migration pattern of dunlin ( calidris alpina ) revealed by mitochondrial dna analysis . molecular ecology . 10 : 1111 - 1120 .

dunlin breed as monogamous pairs in coastal grassland , saltmarsh , upland moorland and arctic tundra . the clutch of 4 eggs is laid in a scrape ; incubation and chick - rearing are shared , and the young leave the nest soon after hatching . dunlin have been recorded to have interbred with white - rumped sandpiper , sanderling and purple sandpiper ( c . maritima ) .

) , genetic analyses from our investigation revealed marked genetic differentiation among some dunlin subspecies based on mtdna analyses . phylogenetic analysis revealed four separate phylogroups with high levels of statistical support ( fig .

hobson , k . , g . slater , d . lank , r . milner , r . gardiner . 2013 . agricultural lands subsidize winter diet of the dunlin at two major estuaries .

warnock , n . , g . w . page & b . k . sandercock ( 1997 ) . local survival of dunlin wintering in california . condor . 99 : 906 - 915 .

figure 2 : the distribution of the southern dunlin ( calidris alpina schinzii ) in the baltic sea area 2000 - 2010 ( including the north sea coast of denmark and schleswig - holstein ) .

the southern sub - species of the dunlin , calidris alpina schinzii , colonises south - eastern greenland , iceland , the faeroe islands , great britain and ireland , southern norway , and the baltic . in the southern north sea ( belgium , netherlands and germany ) , the dunlin has been a breeding bird in the past , but in recent times breeding records have been few and irregular .

browning , m . r . ( 1991 ) . taxonomic comments on the dunlin calidris alpina from northern alaska and eastern siberia . bulletin of the british ornithologists club . 111 : 140 - 145 .

gerasimov , y . n . & n . n . gerasimov ( 2001 ) . records of northward migration of dunlin calidris alpina through kamchatka , russia . stilt . 39 : 37 - 40 .

the dunlin breeds from western and northern alaska east to the hudson bay . it winters along the coast from southern alaska and massachusetts south to mexico . it is also found in northern europe and asia .

hall js , franson jc , gill re , meteyer cu , teslaa jl , nashold s , dusek rj , et al . experimental challenge and pathology of highly pathogenic avian influenza virus h5n1 in dunlin (

as hedgehog numbers increased , ground nesting birds including lapwing , dunlin , ringed plover , snipe and redshank have seen their numbers decline . research demonstrates this is mostly due to the non - native hedgehogs .

yesterday ' s photographs ( digital cameras not being around in 1980 ) captured the dunlin almost always with its head in the water . it was still there at 3pm , but not seen just after 5pm .

given its vagrant status , there are no estimates of the extent of occurrence of the dunlin in australia . the estimated global extent of occurrence is 1 000 00010 000 000 km² ( birdlife international 2007a ) .

goede , a . a . & m . de bruin ( 1985a ) . selenium in a shore bird , the dunlin , from the dutch waddenzee . marine pollution bulletin . 16 : 115 - 117 .

the southern subspecies of the dunlin ( calidris alpina schinzii ) was once an abundant and widespread breeding bird of the baltic sea area . however , during the 20 th century the population declined rapidly and counts currently not more than 500 - 640 bp . from many parts of its former baltic range the dunlin has disappeared . an extinction of the species in the baltic region during the next few decades cannot be excluded .

thorup , o . , z . preiksa , h . pehlak , m . altemüller & h . drews ( submitted ) : status of the baltic dunlin calidris alpina in lithuania . wader study group bull .

warnock , n . , r . gill . 1996 . " dunlin ( calidris alpina ) " ( on - line ) . the birds of north america online . accessed march 10 , 2014 at urltoken .

i can honestly say that despite tramping over dartmoor for a few decades i have never seen sight nor sound of the elusive dunlin . the dunlin or calidris alpina if one wants to be official is a small wading bird that tends to breed in upland bogs and then migrate to low lying mud flats in the winter . it has been said that winter dunlin numbers have declined by around 50 % during the past 25 years . however the uk breeding population remains fairly static but none the less the species appears on the birds of conservation concern red list . it is estimated that the entire uk population numbers around 9 , 600 pairs .

such a striking project by alexandra kidd . a smokey pallet offsets the natural sydney sandstone of this landmark terrace house . lighting from dunlin is used throughout , including the btc cranton pendant and the btc walter pendant .

other names : red - backed sandpiper ; black - bellied sandpiper ; american dunlin ; blackcrop ( bent 1962 ; dement ' ev & gladkov 1951 ; grinnell et al . 1918 ; higgins & davies 1996 ) .

thorup , o . ( 1997 ) : langtidsstudier af baltisk ryle på tipperne . [ long - term studies of baltic dunlin at tipperne ] - dansk orn . foren . tidsskr . 91 : 50 - 51 .

schulenberg , t . s . ( 2010 ) dunlin ( calidris alpina ) . in : schulenberg , t . s . ( ed ) neotropical birds online . cornell lab of ornithology , ithaca . available at : urltoken

perhaps we could see more dunlin - and other things - visiting the wanstead park area , as careful management could see an increasing number of the wide variety of migrants and residents that we already know visit wanstead flats .

goede , a . a . & m . de bruin ( 1985b ) . arsenic in the dunlin ( calidris alpina ) from the dutch waddenzee . bulletin of environmental contamination and toxicology . 34 : 617 - 622 .

lowry , r . j . , r . jensen , j . payne & r . payne ( 1999 ) . a wintering dunlin in north queensland . australian birding . 5 ( 3 ) : 11 - 12 .

pienkowski , m . w . & w . j . a . dick ( 1975 ) . the migration and wintering of dunlin calidris alpina in north - west africa . ornis scandinavica . 6 : 151 - 167 .

shepherd , p . c . f . & d . b . lank ( 2004 ) . marine and agricultural habitat preferences of dunlin wintering in british columbia . journal of wildlife management . 68 : 61 - 73 .

the good news for dartmoor is that its upland bogs and mires are the most southerly breeding area in the world . not only that but dartmoor is the home to the only breeding population of dunlin in southern england . so it should come as no surprise that various bodies are making concerted efforts to maintain the dartmoor dunlin population . one of these major efforts , and i might add controversial , is the notorious ( in some eyes ) ‘

- although it ' s turning the other flank . ( dates support this assumption ) . my thanks to pavel tomkovich , who sent them ; the site is gradually approaching a full hand in dunlin subspecies ! [ cp ]

the dunlin breeds in northern russia , europe , greenland , canada and alaska , and migrates to the coasts of southern north america , south and west europe , north and west africa , the middle east , china and japan .

luís , a . & j . d . goss - custard ( 2005 ) . spatial organization of the dunlin calidris alpina l . during winter - the existence of functional units . bird study . 52 : 97 - 103 .

ruiz , g . m . , p . g . connors , s . e . griffin & f . a . pitelka ( 1989 ) . structure of a wintering dunlin population . condor . 91 : 562 - 570 .

fedorov v . a . ( 2009 ) : nest record of the dunlin calidris alpina schinzii in the kurgalsky zakaznik , leningrad oblast . russian journal of ornithology 486 , express issue 18 : 351 - 354 ( in russian ) .

on the breeding grounds , insects and insect larvae are the most important source of food . in coastal habitats , dunlin also eat marine worms , small crustaceans , mollusks , and other aquatic creatures . they sometimes eat seeds and leaves .

there is no published information on the generation length of the dunlin , but they first breed when one year old , and the oldest bird recorded was 24 years old ( etheridge & taylor 1982 ; van gils & wiersma 1996 ) .

petersen , w . r . , p . k . donahue & n . atkins ( 1981 ) . first record of dunlin ( calidris alpina ) for peru and continental south america . american birds . 35 : 342 - 343 .

kus , b . e . , p . ashman , g . w . page & l . e . stenzel ( 1984 ) . age - related mortality in a wintering population of dunlin . auk . 101 : 69 - 73 .

warnock , n . , j . y . takekawa & m . a . bishop ( 2004 ) . migration and stopover strategies of individual dunlin along the pacific coast of north america . canadian journal of zoology . 82 : 1687 - 1697 .

the canadian wildlife service estimates the dunlin population at 3 , 934 , 000 birds worldwide , with 1 , 325 , 000 in north america . of that group , 500 , 000 birds make up the pacific coast population . dunlin are currently the second most common shorebird in washington , and the most common of washington ' s wintering shorebirds , but numbers have declined in the northwest in recent decades . there has been little habitat destruction or disturbance on the breeding grounds to date , but the migration and wintering grounds are threatened by destruction of habitat . there is currently no reliable information about population status or trends for dunlin range - wide , so it is unknown if the trend in the northwest is due to a decrease in population or a shift in range . dunlin are considered an indicator species for assessing the health of holarctic ecosystems , so determining range - wide population trends should be of high priority as reduction in their numbers could indicate that other species that use these ecosystems are at risk .

perched above the waves of bronte , this elegant coastal home by lane and grove strikes the perfect balance between beachside chic and classic elegance . dunlin assisted with pendant lighting including the davey box family , along with all the outdoor lighting . . . .

wennerberg l , n . m . a . holmgren , p . e . jönsson , t . von schantz ( 1999 ) . genetic and morphological variation in dunlin calidris alpina breeding in the palearctic tundra . ibis . 141 : 391 - 398 .

on the 9th of september 2007 during a full - day birdwatching tour through madeira nature with madeira wind birds , one dunlin of the subspecies alpina was observed in ribeira da janela , seixal . the observers were helen & paul colto from uk , catarina & hugo from madeira wind birds . the main characteristics that allow the observers to identify it as the ssp alpina of a dunlin were its longer bill , its clearer head and breast with the distinct black belly and the bright rufous colour near the wing .

although our new findings do not specifically identify strategies for preventing the transmission of hpai into north america , they nonetheless reveal a mechanism by which dunlin could facilitate the spread of hpai into north america and mexico . this is particularly pertinent given that dunlin are highly susceptible to infection with the h5n1 hpai , and that some individuals may live to spread the disease , possibly after undergoing a migration ( hall et al . 2011 ) . although only a few dunlin sampled in western north america have been documented with actively shedding ai ( ip et al . 2008 ; iverson et al . 2008 ; usfws and usgs 2011 ) , the continued emergence of new hpai strains ( e . g . , h5n8 , h7n9 ) and the fact that most efforts to date have detected prior exposure ( i . e . , antibodies , see pearce et al . 2012 ; johnson et al . 2014 ) indicates that the evolution of new strains remains problematic and that dunlin are a potential route for hpai to reach and spread within north america .

lavers , c . p . & r . h . haines - young ( 1997 ) . the use of satellite imagery to estimate dunlin calidris alpina abundance in caithness and sutherland and in the shetland islands . bird study . 44 : 220 - 226 .

at the baltic coast of schleswig - holstein , germany , the dunlin has been a widespread breeder in the past ( e . g . , boie 1822 ) , but disappeared during the 1990s . however , at the north sea coast it re - established as a breeding bird in 2007 in the rickelsbüller koog close to the danish border . in this area ( rickelsbüller koog and the adjacent margrethe kog ) , the dunlin had already disappeared in 1996 . the number of breeding pairs were 1 bp in 2007 , 2 bp in 2008 , 5 bp in 2009 and 4 bp in 2010 . the return of the dunlin to the rickelsbüller koog is probably related to dispersal or interchange of birds from the danish breeding sites on rømø ( distance c . 25 km ) .

with an extremely large range and a relatively large population , the dunlin is not at immediate risk of extinction . however , there are a great number of threats to this species , with the loss of its breeding habitat through afforestation particularly problematic ( 5 ) .

warnock , n . d . and gill , r . e . ( 1996 ) dunlin ( calidris alpina ) . in : poole , a . ( ed ) the birds of north america online . cornell lab of ornithology , ithaca . available at : urltoken

lavers , c . p . & r . h . haines - young ( 1996 ) . the pattern of dunlin calidris alpina distribution and abundance in relation to habitat variation in the flow country of northern scotland . bird study . 43 : 231 - 239 .

gene and control region along with eight nuclear microsatellite loci to address multiple questions associated with the differentiation of dunlin subspecies and the extent of gene flow and interactions among groups from asia and north america . ( i ) do genetic data provide evidence for differentiation among dunlin subspecies and breeding populations from the region ? while prior work has examined phylogeographic patterns in the northern hemisphere , most studies were based on small sample sizes and had limited ( or no ) sampling within beringia - associated subspecies ( e . g . , wenink and baker

many thanks to dennis paulson for bringing this wonder bird to my attention and of course to wayne richardson for his stunning photographs . thanks also to norman deans vans swelm for the bringing the dutch dunlin ( ? ) to our attention and providing his very useful photograph .

buchanan , j . b . , c . t . schick , l . a . brennan & s . g . herman ( 1988 ) . merlin predation on wintering dunlins : hunting success and dunlin escape tactics . wilson bulletin . 100 : 108 - 118 .

durell , s . e . a . le v . dit & c . p . kelly ( 1990 ) . diets of dunlin calidris alpina and grey plover pluvialis squatarola on the wash as determined by dropping analysis . bird study . 37 : 44 - 47 .

lesterhuis , a . j . & r . p . clay ( 2003 ) . the first record of dunlin ( calidris alpina ) in paraguay and a summary of south american records of the species . el hornero ( b . aires ) . 18 : 65 - 67 .

the southern dunlin ( calidris alpina schinzii ) is a characteristic bird of grazed coastal meadows , but small numbers also breed on peat bogs . nowadays , the breeding sites are almost exclusively found in coastal areas , whereas in the past the species was also common in the inland .

table 2 : population numbers of the dunlin in the baltic sea area 1994 - 1998 and 2007 - 2011 . data for 1994 - 1998 according to helcom ( 2002 ) . for denmark and schleswig - holstein , the numbers include the breeding pairs at the north sea coast .

warnock , nils d . and robert e . gill . 1996 . dunlin ( calidris alpina ) , version 2 . 0 . in the birds of north america ( p . g . rodewald , editor ) . cornell lab of ornithology , ithaca , new york , usa .

the dunlin is a familiar shorebird around the world , where its bright reddish back and black belly , and long , drooping bill distinguish it from nearly all other shorebirds . it breeds across the top of both north america and eurasia , and winters along coasts around the northern hemisphere .

tundra - breeders , dunlin typically nest in wet meadow tundra with low ridges , vegetation hummocks , and nearby ponds . during migration and winter , they prefer mudflats , but can also be seen on sandy beaches , coastal grasslands , estuaries , and occasionally in muddy , freshwater areas .

the dunlin is a small migratory wader that exhibits great variability in body and bill size , and plumage , leading to it being easily confused with a number of other small waders . in particular it is similar to the slightly larger curlew sandpiper , but with shorter legs and bill .

the global population is estimated to number 4 , 600 , 000 / 6 , 500 , 000 individuals ( wetlands international 2006 ) . the overall population trend is decreasing , but some races such as arctica and shinzii are considered stable . the dunlin is currently evaluated as least concern .

pairwise and global estimates of f st for dunlin ( calidris alpina ) subspecies . f st values are shown below matrix diagonals while p - values are above matrix diagonals . ( a ) mtdna ; ( b ) microsatellite analyses ; ( c ) microsatellite analyses assuming a stepwise mutational model

the dunlin is a small ( length : 1622 cm ; weight : 60 g ) sandpiper with a shortish drooping bill , short wings and legs , and a hunched posture . the sexes are similar in both breeding and non - breeding plumage , but juveniles are separable from adults .

blomqvist , s . , a . frank & l . r . petersson ( 1987 ) . metals in liver and kidney tissues of autumn - migrating dunlin calidris alpina and curlew sandpiper calidris ferruginea staging at the baltic sea . marine ecology progress series . 35 : 1 - 13 .

the population decline of the dunlin in the baltic sea area should be stopped or , if possible , even reversed by an appropriate management ( habitat management / management of predators ) of the still existing breeding sites and other appropriate sites , especially those where the species has disappeared recently .

because the dunlin have been and are so rarely encountered on dartmoor there is no folklore attached to them which is a shame . maybe in future years when their numbers on dartmoor have increased they will become a ‘ legendary ‘ success story for the various bodies concerned with their conservation ?

goss - custard , j . d . & m . e . moser ( 1988 ) . rates of change in the numbers of dunlin , calidris alpina , wintering in british estuaries in relation to the spread of spartina anglica . journal of applied ecology . 25 : 95 - 109 .

this entry was posted in biodiversity , birds , wildlife management and tagged biodiversity , bird , birds , coast , conservation , dunlin , hedgehogs , lapwing , nest predation , redshank , ringed plover , scottish natural heritage , snh , snipe , waders , wildlife management . bookmark the permalink .

introduction : the dunlin is a circumpolar breeder . it breeds far north in the arctic and winters southwards in more temperate regions . this species is common , but the overall population trend is decreasing , due to the usual threats including habitat loss on the breeding grounds , nest predation by introduced mammals on some islands , disturbances , pollution… the dunlin has currently ten subspecies , but some of them are still uncertain . this species is gregarious outside breeding , and they often gather in huge flocks . if they are disturbed , they all fly off together , turning and flying in unison .

this study is concerned with the ability of two wader species , the sanderling , calidris alba and the dunlin , c . alpina to determine the presence of prey in a sediment by using their sense of taste , and whether they use this information while foraging for prey hidden in the sediment .

stockholm 350xx20 , migrant 3c + female , ljunghusen , 8 . 7 . 05 . the female dunlin has much more dots and shades in her face , her indicated lores are wider and in most cases she lacks the bill - base " goggles " ( seen from above , cf . picture

in finland , the southern dunlin has never been numerous . the first documented breedings date back to the 1880s . in the 1960s , the dunlin was still considered increasing , with a country total of 150 - 200 bp ( soikkeli 1964 ; perttula 1998 ) . new breeding sites were still found in the mid - 1980s when the population peaked at 200 pairs . however , until the early 1990s the population had declined to 100 bp . in 1999 the number of confirmed breeding pairs was 71 , and in recent years ( 2003 - 2009 ) the number was about constant between 50 and 60 bp .

the name , first applied long ago , simply means " little dun - colored ( gray - brown ) bird , " a good description of the dunlin in winter plumage . spending the winter farther north than most of its relatives , this species is a familiar sight along the outer beaches during the cold months , as far north as new england and even southern alaska . it is often in large flocks ; in flight , these flocks may twist and bank in unison , in impressive aerial maneuvers . in breeding plumage , the dunlin is so much more brightly colored as to seem like a different bird .

the dunlin ( calidris alpina ) is one of the hardiest of all shorebirds , breeding far north in the arctic region and migrating southwards before the onset of winter ( 3 ) . this species is also renowned for its beautiful breeding plumage , which is distinguished by the reddish cap , bright reddish - brown back and black belly patch , which extends behind its black legs . the head and breast are pale brown . outside of the breeding season , the dunlin is light brownish - grey with a brownish back , white underparts and a brownish band streaking across the upper breast ( 2 ) ( 4 ) .

dunlin : breeds along the arctic coast from western and northern alaska east to hudson bay . spends winters along coastlines from southern alaska and massachusetts southward to mexico ; also found in parts of eurasia . nests on tundra and winters on beaches , mudflats , sand flats , inland lakes , and river shores .

probably much to the annoyance of those who disapprove of the mires project , the findings of this survey proved very encouraging as far as the dunlin numbers go . it has been reported that there has been a thirty seven percent increase in territorial pairs over the past four years . in 2010 it was thought that there were sixteen pairs living on dartmoor , in 2014 these numbers had increased to twenty two pairs . if one looks at the ‘restored’ sites , i . e . those that have been the subject of mire restoration , again the results are encouraging . at one site the numbers of breeding pairs had increased from two to three . at another they had increased from three to six and at a third a pair had been recorded for the first time . needless to say these findings have been quickly used as ammunition in the debate as to whether or not the mires project should have been instigated . the dartmoor national park authorities director of conservation and communities , alison kohler has commented that ; “ the project partners are really excited to see such a rapid response by our dunlin population . this is a fantastic success story for the dunlin ( which particular dunlin she does not say ) and for the dartmoor mires project . ”

the dunlin is migratory and performs short coastal flights to long , non - stop flights overland in broad front . they moult in large concentrations on or near the wintering areas . some immature birds may spend all the year in the non - breeding range , but most of them return to the breeding grounds .

the dunlin has a very wide distribution , occurring across nearly all arctic regions . its breeding range stretches from east greenland , across the russian arctic to the alaskan coast of the bering sea . there is also an isolated population that breeds in the east canadian arctic ( 5 ) ( 6 ) ( 7 ) .

dunlin : call is a simple " kree . " song is a series of frog - like wheezing calls and long trills , such as " wrrrrrah wrrrrrah wrrrrrah " and twittering " chrri - i - i - i - i - i - ri - ri - ri - ri - ri - ri . "

migratory birds may facilitate the spread of hpai from asia to north america ( winker and gibson 2010 ) . in this investigation , we used large sample sizes and two genetic data sources ( mitochondrial dna and microsatellites ) to determine genetic structure patterns among six dunlin subspecies that reside in and migrate through eastern asia and north america . we specifically focused on determining whether the four subspecies of dunlin that winter in asia can be differentiated and if genetic evidence for gene flow among beringian subspecies exists . we suggest that our results may be useful for documenting potential hpai transmission routes and the pathways that may facilitate the spread of disease across continents .

in the st petersburg region of russia the dunlin is obviously still a rare or sporadic breeder . in 2008 , a nest was found on the shore of kurgalsky peninsula ( fedorov 2009 ) . in 2010 , an adult bird with typical breeding behaviour was seen on a small islet near sescar island ( fedorov , pers . comm . ) . in the kaliningrad region the dunlin was known as a breeding bird until 2001 ( 1989 - 93 : 4 - 5 bp ; 1996 - 99 : 3 pairs ; 2001 : 2 pairs ) . after that year , no further breeding could be confirmed ( grishanov & lykov 2008 ) .

the dunlin has also been extensively hunted in the past , although this is now a lesser threat ( 2 ) , and it is susceptible to avian influenza ( 5 ) . in some areas , introduced predators such as the hedgehog ( erinaceus europaeus ) have greatly reduced the breeding success of this species ( 6 ) .

assuming that our sample of individuals and subspecies is representative of dunlin from east asia , our analysis suggests that we can use our data to obtain rudimentary estimates of the probability of correctly distinguishing asian - versus alaskan - breeding birds with mtdna when sampling takes place in the east asian nonbreeding areas . with the exception of seven

wenink , p . w . , a . j . baker , & m . g . j . tilanus ( 1994 ) . mitochondrial control - region sequences in two shorebird species , the turnstone and the dunlin , and their utility in population genetic studies . molecular biology and evolution . 11 : 22 - 31 .

ironically , although the dunlin can be considered as a dartmoor rarity they are in fact one of the commonest coastal waders . in winter it is possible to see feeding flocks of around one thousand birds roosting in salt marshes and shorelines . their preferred diet is one that consists of insects , worms and snails and their breeding season lies between april and july . they are ground nesting birds which i suppose is obvious when looking at dartmoor blanket bog – not many other options there . the typical dunlin clutch consists of four eggs which when hatched are left to the male bird to feed , after about three to four weeks they are airborne and self supporting .

habitat : the dunlin breeds in a wide variety of habitats including boggy tundra , moorland often close to pools , wet coastal grassland and salt marshes , tussock tundra and peat - hummock in arctic . after breeding , it frequents tidal mudflats , freshwater lakes , brackish lagoons , sandy beaches and flooded fields , and also estuarine mudflats .

behaviour in the wild : the dunlin feeds by walking or running , while picking rapidly at the surface . it is sometimes called the “sewing machine” because it bobs the head up and down and pokes into the ground with the bill while feeding . it forages in open mud near the water’s edge , and wades in shallow water .

sikora , a . , m . wieloch , m . zielińska , t . mokwa , p . chylarecki , p . zieliński & z . rohde ( 2008 ) : monitoring of rare species ( whooper swan , ferruginous duck , dunlin , and mediterranean gull ) , report for the chief inspectorate of environmental protection 2007 , gdansk .

as a breeding bird of coastal , grazed meadows which are exposed to regular flooding the dunlin maybe considered as an indicator for the quality of this habitat type . since several other waders ( e . g . , ruff , black - tailed godwit , redshank , avocet , lapwing ) are breeding in the same or similar habitats , the dunlin is an indicator for the habitat availability and quality for this group of coastal birds . the coastal waders are a bird group of special conservation concern in the baltic sea area , since several species meet the criteria for a threat category according to the helcom red list of baltic breeding birds ( helcom , in prep . ) .

breeding distribution the dunlin has a virtually circumpolar breeding distribution , with populations breeding in greenland , iceland , britain , scandinavia , northern russia , alaska and northern canada ( barter 2005b ; browning 1991 ; cramp & simmons 1983 ; dement ' ev & gladkov 1951 ; gromadzka 1989 ; maclean & holmes 1971 ; van gils & wiersma 1996 ) .

the dunlin is protected by the provisions of the eu birds directive ( directive 2009 / 147 / ec of the european parliament and of the council of 30 november 2009 on the conservation of wild birds ; this is the codified version of directive 79 / 409 / eec ) , which are implemented by the member states into national law . this means , the legal protection status of the species is similar in all baltic sea states , which are members of the european union . it is listed in annex i of the bird directive , i . e . , eu member states are obliged to establish special protected areas ( spa ) . in russia , the dunlin is also protected .

a migratory species , the dunlin has a number of sub - populations that each has differing migration behaviours . for instance , the sub - population that breeds in north - east greenland migrates through iceland , britain and western france to arrive in its west african wintering grounds from late july , returning again between march and early april ( 5 ) .

in north america , the dunlin is protected by the north american migratory bird treaty act of 1918 , which protects this species and its eggs from hunting and collection ( 2 ) . in the uk , this species is also well protected in special protected areas , with around 74 percent of the total breeding population found in such reserves ( 6 ) .

the dunlin is an indicator for habitat changes , which not only affect this species , but also other wader species which live in the same or similar habitats , such as ruff ( philomachus pugnax ) , black - tailed godwit ( limosa limosa ) , redshank ( tringa totanus ) , avocet ( recurvirostra avosetta ) , and lapwing ( vanellus vanellus ) .

other topics in shorebird identification ( complete listing here ) eastern or western willet ? age and sexing of a bar - tailed godwit . pacific versus american golden - plover . black - tailed godwit - islandica or limosa ? black - tailed godwit - identification of the asiatic subspecies melanuroides . red - necked stint and little stint identification . curlew sandpiper or dunlin ?

during the breeding season , they perform a low display flight with quivering wingbeats interspersed with glides . they circle slowly over the breeding territory . they are monogamous and solitary nesters , with usually 3 - 30 birds / km² . in front of a rival or an intruder , the dunlin reacts by advancing , then pausing to raise one wing vertically high over back .

the key management documentation for the species in the east asian - australasian flyway is keeping the common shorebirds common : action planning to save the dunlin by barter ( 2005b ) . there is a detailed summary of all that is known of the species in europe in cramp and simmons ( 1983 ) and a briefer summary in van gils and wiersma ( 1996 ) .

wenink , p . w . , a . j . baker , & m . g . j . tilanus ( 1993 ) . hypervariable - control - region sequences reveal global population structuring in a long - distance migrant shorebird , the dunlin ( calidris alpina ) . in : proceedings of the national academy of sciences of the usa . 90 : 94 - 98 .

there are no confirmed breeding records of the dunlin in latvia from recent times . during the elaboration of the second latvian breeding bird atlas 2000 - 2004 ( in preparation , results are available online : urltoken ) breeding of dunlins has been suspected for 3 sites : ainazi and randu plavas , teich bog and daugavgriiva . the population is estimated at 0 - 7 bp .

a : consumption rate ( prey / min ) of main prey . b : occurrence of shell remains of h . ulvae in dunlin droppings . values represent mean ± se . differences between seasons were tested with ( a ) mann - whitney ( b ) and chi - squared tests ( * p < 0 . 05 ; * * * p < 0 . 001 ) .

calls and songs : sounds by xeno - canto the dunlin gives a shrill , rasping “kreeep” in flight . while feeding in flocks , they produce a low “beep” and a soft twittering at roost . on the breeding grounds , it utters prolonged , reedy , descending trilled whistles while displaying . when alarmed , it produces a sharp “quoi” and a low “wurt - wurt - wurt” .

protection / threats / status : the dunlin has large range . it is threatened by habitat loss in its breeding grounds , and drainage of wetlands involving changes in estuaries where it often spends the winter . nest predation by introduced mammals on some islands is a problem too . some important migratory stopovers on the baltic sea coastline are threatened by petroleum pollution and various changes in the habitat .

after 1 june , what hasn ' t been exchanged then is suspended . some west - / north - palaearctic populations have a very lack - lustre breeding plumage , they may for example breed with three unmoulted winter scapulars . there seems to be some extra cost connected with belonging to a marginal dunlin population , lying a little apart from the main migration flyways and population " centres " (

dunlin flocks are often huge , most impressive when they display their coordinated aerial maneuvers trying to escape predation by peregrine falcons and merlins . when foraging , they either pick food from the surface or probe in the mud . they feed on exposed mud or in shallow water , making short runs interspersed with periods of feeding . they feed day or night , depending on the timing of low tide .

telling winter waders apart can be daunting . success in this ( and if you are keen to find rarer species ) is not difficult , provided you are familiar with two key species : knot and dunlin . this guide tackles these two ‘confusing calidrids’ , familiarity with these is essential in order to gain experience and confidence identifying the apparently bewildering range of waders on our coasts in autumn and winter .

there have been two confirmed records of the dunlin in australia : at cairns , queensland , on 4 january 1983 ( roberts 1983 ) ; and cape bowling green , queensland , on 1 july 1999 ( lowry et al . 1999 ) . there have been numerous other unconfirmed or doubtful reports , from queensland , victoria , tasmania , south australia and western australia ( higgins & davies 1996 ) .

dear angus , the unidentified sandpiper shown on your website made me remember a dunlin my son charles and i found in may 2001 here in the sw netherlands ( see fig . 6 ) . in my opinion this long - billed individual is an american bird c . a . hudsonia and very similar to a bird photographed by richard chandler and shown on the cover of british birds some years ago .

the dunlin in breeding plumage has rufous upperparts with blackish , white , greyish and chestnut markings . mantle , scapulars and tertials are blackish with variable chestnut , grey or whitish fringes . the wing - coverts are grey - brown with pale grey to whitish fringes . the flight feathers are blackish - brown , whereas sides of rump and uppertail are white , and sides of tail are greyish - brown .