text: During Charles Darwin’s journey to the Galápagos in the 1830s, he noted the existence of “a curious group of finches” found only on the islands. The story that those birds inspired the theory of evolution has long been doubted. But the finches still bear Darwin’s name and are prized by biologists as one of the best examples of speciation—the process by which new species arise. 
   
   Now, research suggests that at least some of Darwin’s famous finches might soon be driven to extinction by parasitic flies introduced to them by humans in the 1960s. A paper published this week in the Journal of Applied Ecology blames the parasitic nest fly Philornis downsi for the threat to Geospitza fortis, also known as the medium ground finch. 
   
   While adult P. downsi flies are not themselves parasitic, they lay their eggs in bird nests. The eggs hatch into maggots, which feed on both brooding adult finches and their babies. The adult birds are unaffected, but it’s another story with the tiny nestlings. P. downsi kills huge numbers of baby birds among Darwin’s finches and other land birds. The flies can be found on every island in the Galápagos. 
   
   “This is like a really bad horror flick,” senior author Dale Clayton, an ecologist and parasite specialist at the University of Utah, says with a rueful laugh. “The babies can’t withstand even one night with these parasites.” The susceptibility of the baby finches has something to do with their size—Clayton compares the newly-hatched birds to peanut M&M's—and their immune responses. 
   
   The sight of a parasite-infested G. fortis isn’t just alarming because of the tiny bird’s anemic looks and bulging lesions. It is also a harbinger of the species’ coming extinction. Clayton and his team used five years of field data to predict the species’ long-term viability and found that, in two out of three scenarios, medium ground finches could be gone within the next century. 
   
   The team first manipulated the parasite load in actual nests, studying only the medium ground finches, which are the most abundant and have the most accessible nests. They created a control group of nests that they sprayed with plain water, while a second set of nests was sprayed with permethrin, an insecticide that is also used to kill mosquitoes, lice and ticks. The use of treated and untreated nests allowed the team to determine the direct effects of the flies on the birds. They then used that data in models of good, bad and neutral years for the birds’ reproduction and ultimate survival. 
   
   The team predicts that if the finches were to run into a series of bad reproductive years in which extreme weather cuts off their food supply, they’d go extinct in about 50 years. A model weighted toward neutral years indicates they’d be extinct within about 80 years. Unsurprisingly, a run of good reproductive luck would spell longer survival for the species: about 100 years. Reducing the number of flies could help the birds hold on even longer, or even prevent them from going extinct at all. 
   
   While Clayton’s team focused on medium ground finches, given that there are at least 14 species of Darwin's finches in the Galápagos—and that they are so closely related—the problem likely extends to other species. 
   
   For instance, a cousin of the ground finch, the mangrove finch, has already become one of the rarest birds on Earth due to the flies and other predators. If any species is lost, it will be a disaster not just for biodiversity, but for researchers who see the finches as an example of real-time evolution due to their rapid adaptations. 
   
   Since the Galápagos so far has its entire native population of birds intact, its importance to biologists is unparalleled. But for Clayton, it goes further than that. “If Darwin’s finches go extinct, it will be because people brought this fly to the islands,” he says. “If the fly had gotten to the island more gradually, perhaps, maybe the birds would have had more time to adapt. But at this point, it’s just an arms race.” 
   
   Luckily, there are ways that the finches could beat both P. downsi and time. The team estimates that if nest fly infestations were reduced by just 40 percent, the birds won’t go extinct. Scientists are batting around ideas such as flooding the island with sterile male flies or allowing birds to fumigate their own nests with permethrin. 
   
   And don’t underestimate evolution, either: Clayton says there’s an outside chance the finches could still develop their own defenses against the flies. In the meantime, can humans stave off the finches’ untimely demise? “Maybe not. But we’re hopeful.” ||||| An even more compelling mystery concerns a common sight in springtime—bright blue eggs in a robin’s nest. To human eyes, they are beautifully unmistakable. They stand out from both the nest and the parent birds, so why are they bright blue? No one yet knows for sure. Biologists do know that pigment glands in the mother bird’s body deposit the blue coloration onto the eggs, so it must have a critical function. Perhaps the dark color camouflages the eggs when the eggs are at the bottom of a dark nest, or the blue might blend in with the sky for some viewers. Some researchers have even speculated that the striking color helps mother birds to find their own eggs. For now, however, the case of the mysteriously blue robin’s egg has yet to be cracked. 
   
   This Adelie penguin laid a speckled egg that matches its environment. The matching phenomenon could lead to a twist to the old riddle: Which came first, the chicken or the egg? In this case, the teaser could be: Which came first, the egg color and pattern, or the choice of nesting site? 
   
   By itself, the egg of a swan is just as visible as a bright white egg on a breakfast plate. Under the mother swan, however, the egg disappears. 
   
   This cockatiel, with its proud expression, has a right to boast. Its egg not only matches the mother bird’s coloration, but it also matches the environment. In the wild, a hunter would have a hard time finding such an egg. 
   
   A mother cowbird must have worked hard to find this perfect spot for her eggs. “Interestingly, all birds seem more concerned in minimizing the mismatch between nest and the darker speckles on their eggs than the mismatch between nest and the underlying, predominant egg color, but particularly so for birds with more dark speckling,” Cuthill said. Lovell and his team speculate that the dark and light markings serve as a disruptive camouflage, breaking up the outline of the otherwise revealing oval shape. That shape, for humans and countless other predators, serves as a visual signal for good eats. 
   
   Sometimes avian parents enjoy the best of both worlds: camouflage for their eggs as well as fooling other birds. Cuckoo finches can be deadbeat parents, matching their eggs (seen in the inner circle) to those of the tawny-flanked prinia (outer circle). The prinia parents are sometimes fooled into caring for the cuckoo finch eggs and later hatchlings. 
   
   Brown with speckles is just one egg color/pattern combo, as these reed warbler eggs reveal. Their greenish hue, set off by the green leaves surrounding the nest, would make them less visible to predators scanning the area from a distance. This nest also includes a, slightly larger, common cuckoo egg. Demonstrating another bit of bird trickery, common cuckoo mothers frequently match the appearance of their eggs to those of reed warblers, which wind up caring for the hatchlings. 
   
   Japanese quail themselves are brown and speckled, like their eggs. The bodies of many birds appear to match their eggs. A parent bird could then likely better shield the egg when resting upon it. Speckles appear to be key to camouflage, at least for eggs. Avian expert Innes Cuthill of the University of Bristol’s School of Biological Sciences, told Discovery News, “Alfred Russel Wallace concluded that the brown and speckled colors of many eggs had evolved as camouflage against nest predators and that the ancestral color of white only persisted in species whose eggs were laid in well-protected cavities, were covered by nest material or, in birds such as ostriches, could be defended by their parents.” 
   
   Yet another Japanese quail egg matches its environment, but the egg is not invisible to us. “Some have asked why they can still see the eggs if they are camouflaged,” Lovell said. “It’s important to remember that the eggs are less visible, not invisible…The photographs are taken quite close up to the egg, and a predator wouldn’t necessarily be that close. It would be scanning an area, rather than staring straight at the egg.” 
   
   Close-ups of the individual Japanese quail eggs really show how well the bird moms can match their eggs to the environment. One of the first scientists to theorize that coloration and speckles evolved for camouflage against predators was Alfred Russel Wallace, who gained fame as Charles Darwin’s co-discoverer of the principle of natural selection. 
   
   Eggs come in a multitude of colors and patterns, from subtle pastels to vivid bright hues. Now a new study, published in Current Biology, supports a centuries-old theory that shell variation, at least for some birds, helps to camouflage eggs. The masters of egg disguise turn out to be Japanese quail. This photo amazingly features eggs just from this one species. Mother quails somehow learn the patterning of their own eggs and choose laying spots to hide them best. “We currently do not know the mechanisms by which the (mother) bird learns its own egg patterns,” lead author P. George Lovell of Abertay University and the University of St. Andrews, told Discovery News. Nevertheless, the ground-nesting birds often perfectly match the eggs to substrate, helping to prevent the precious contents from being some hungry predator’s dinner. 
   
   A species of Darwin’s finch could face extinction in as little as four decades because of a parasitic fly, new mathematical models show. 
   
   In a study that will be published December 18 in the Journal of Applied Ecology, University of Utah researchers forecast turbulent flying ahead for the medium ground finch (Geospiza fortis), one of the most common of the dozen-plus species of Darwin's finch. (They're named for the man who first collected them, naturalist Charles Darwin, who used observations of the finches' adaptations to inform his work on natural selection. They're also known as Galapagos finches, for the islands they call home.) 
   
   The fly in question is the nest fly Philornis downsi, first documented in birds’ nests in the Galapagos in 1997. It lays its eggs in finches' nests, the larvae infesting the area and feeding, to a fatal degree, on new nestlings. 
   
   Eggs Say ‘Hey Mom We Match’: Photos 
   
   This medium ground finch has nostril and abdomen lesions caused by a nest infested with parasitic fly larvae. Jennifer Koop, University of Utah 
   
   The researchers gathered five years’ worth of data from the island of Santa Cruz, documenting the harm the fly was causing to the finch’s reproductive success. Then they used those results to help fuel mathematical models of different long-term outcomes for the finch species. 
   
   The team ran simulations based around three broad future scenarios: “good” years likely to come, where conditions such as weather and food supply were conducive to successful breeding; “bad” years ahead; and neutral years, where both bad and good conditions were equally likely. 
   
   Two of the three model runs -- "bad" and neutral -- predicted the medium ground finch's extinction. Only the "good" model showed the species able to survive. 
   
   The "bad" model predicted extinction in anywhere from 43 to 57 years, while the "neutral" model had the bird disappearing in 65 to 95 years. 
   
   Video Shows Birds Having An Argument 
   
   Worse still, the problem may not just apply to the medium ground finch. Study lead author Dale Clayton, a University of Utah biology professor, pointed out that the bird's other Galapagos cousins could be at risk as well. 
   
   If a species of Darwin's finch as common as the medium ground finch can face extinction because of the nest fly, "then the less common species, which have the same fly problem, are likely at risk as well," Clayton said in a release. 
   
   Pretty Plumage Sets These Shimmering Birds Apart: Photos 
   
   Glum scenarios aside, there is still hope. The bird's extinction risk is closely tied to the fly infestation problem, so there's no mystery, and the scientists have a clear target. 
   
   “Even though these guys may be going locally extinct, the model also shows that if you can reduce the probability of infestation, then you significantly alleviate the risk of extinction,” said study co-author Jennifer Koop, a professor of biology now teaching at the University of Massachusetts Dartmouth. She said extinction could be avoided if nest infestation could be reduced by 40 percent. 
   
   World's Oldest Known Bird: Photos 
   
   To tackle the problem, the scientists suggested several tactics to fight the fly and rescue the finch. Use of insecticides, introduction of fly-parasitizing wasps, breeding of sterile male nest flies to suppress egg production, and even the hand-rearing of at-risk chicks could each help improve matters, the scientists said. 
   
   Other good outcomes might come from the birds themselves. Clayton said a “rapid evolutionary response” by the birds could spur their immune systems to figure out how to defeat the fly. 
   
   “That happens in other animals,” he said. “The question is: Will these finches have enough time to develop effective defenses before they are driven to extinction by the fly? It’s an arms race.”
target: – Charles Darwin's finches of the Galapagos Islands—renowned as a poster child for speciation (that's "the process by which new species arise," explains Smithsonian)—may not be able to evolve fast enough to stave off extinction, according to a study published last week in the Journal of Applied Ecology. The medium ground finches of Santa Cruz Island are having their newly hatched babies decimated by Philornis downsi, a parasitic nest fly humans brought to the islands half a century ago. The flies lay their eggs inside the birds' nests, and the hatching maggots feed on the young birds. "This is like a really bad horror flick," study author Dale Clayton says. "The babies can't withstand even one night with these parasites." According to Discovery News, the flies were first spotted in the finches' nests in 1997. Since then, the population has been growing, and none of the Galapagos Islands is free of the flies. Researchers looked at five years of field research on the medium ground finches specifically on Santa Cruz and came up with three scenarios—good, bad, and neutral—based on breeding, weather, and food supplies, Discovery News reports. In both the bad and neutral scenarios, the finches have less than 100 years before they're extinct. According to Smithsonian, the same fate is likely facing some of the other 14 species of Darwin's finches. "If Darwin's finches go extinct, it will be because people brought this fly to the islands," Clayton says. "If the fly had gotten to the island more gradually, perhaps, maybe the birds would have had more time to adapt." Researchers believe a 40% reduction of nest infestations could save the finches and are looking at options to accomplish that, Discovery News reports. (A frog named for Darwin has already gone extinct.)