Can all birds fly?
10589364#2
For flight to occur in Aves, four physical forces (thrust and drag, lift and weight) must be favorably combined. In order for birds to balance these forces, certain physical characteristics are required. Asymmetrical wings, found on all flying birds with the exception of hummingbirds, help in the production of thrust and lift. Anything that moves through the air produces drag due to friction. The aerodynamic body of a bird can reduce drag, but when stopping or slowing down a bird will use its tail and feet to increase drag. Weight is the largest obstacle birds must overcome in order to fly. An animal can more easily attain flight by reducing its absolute weight. Birds evolved from other theropod dinosaurs that had already gone through a phase of size reduction during the Middle Jurassic, combined with rapid evolutionary changes. Flying birds during their evolution further reduced relative weight through several characteristics such as the loss of teeth, gonadal hypertrophy, and fusion of bones. Teeth were replaced by a lightweight bill made of keratin, and chewing moved to the bird's gizzard. Other advanced physical characteristics evolved for flight are a keel for the attachment of flight muscles and an enlarged cerebellum for fine motor coordination. These were gradual changes, though, and not strict conditions for flight: the first birds had teeth, at best a small keel and relatively unfused bones. Pneumatic bone, that is hollow or filled with air sacs, has often been seen as an adaptation reducing weight, but it was already present in non-flying dinosaurs, and birds on average do not have a lighter skeleton than mammals of the same size. The same is true for the furcula, a bone which enhances skeletal bracing for the stresses of flight.
Origin of avian flight
3410#47
Most birds can fly, which distinguishes them from almost all other vertebrate classes. Flight is the primary means of locomotion for most bird species and is used for searching for food and for escaping from predators. Birds have various adaptations for flight, including a lightweight skeleton, two large flight muscles, the pectoralis (which accounts for 15% of the total mass of the bird) and the supracoracoideus, as well as a modified forelimb (wing) that serves as an aerofoil.
Bird
927476#0
Flightless birds are birds that through evolution lost the ability to fly. There are over 60 extant species including the well known ratites (ostrich, emu, cassowary, rhea and kiwi) and penguins. The smallest flightless bird is the Inaccessible Island rail (length 12.5 cm, weight 34.7 g). The largest (both heaviest and tallest) flightless bird, which is also the largest living bird, is the ostrich (2.7 m, 156 kg). Ostriches are farmed for their decorative feathers, meat and their skins, which are used to make leather.
Flightless bird
173429#4
A version also exists in India, Pakistan, Germany, Slovakia and Hungary where an analogy to what can fly and what cannot is emphasized instead of Simon saying or not, i.e. "Chidiya ud" (Hindi) which translates to "Bird fly" or "Alle Vögel fliegen hoch" (German) which is "All birds fly high". The term 'bird' can then be replaced with a thing that cannot fly. These games are usually played more with gestures than actual jumping.
Simon Says
12943572#3
What can be said is that "Foro", with its stocky body and rather weak flight apparatus was in all likelihood a bird that did not fly vast distances. Consequently, it is not very likely that it is congeneric with "Hoatzi", as North and South America were still separate by some of shallow seas and the Central American island arc when these birds lived, and seem to have shared only strong-flying and highly migratory genera such as seabirds. Being able to fly at all would still enable even a rather sedentary bird lineage to spread across all of the Americas by then of course; "Foro" and "Hoatzi" seem to be distinct genera, but nonetheless in some way related and possibly quite closely so.
Foro (bird)
2001513#2
The variegated tinamou is a monotypic species. All tinamou are from the family Tinamidae, and in the larger scheme are also ratites. Unlike other ratites, tinamous can fly, although in general, they are not strong fliers. All ratites evolved from prehistoric flying birds, and tinamous are the closest living relative of these birds.
Variegated tinamou
782680#7
Consideration should also be made to the issue of house cats and other predators, by placing the bird bath in a location where birds can see the area around it, and where there are no hiding places for predators. Birds cannot fly well when their feathers are wet, so it's best to allow 2 feet of open space on all sides of the bath, so that birds can see danger coming with enough time to escape.
Bird bath
9516619#1
All tinamou are from the family Tinamidae, and in the larger scheme are also ratites. Unlike other ratites, tinamous can fly, although in general, they are not strong fliers. All ratites evolved from prehistoric flying birds, and tinamous are the closest living relative of these birds. Formerly, this bird was divided into two subspecies: "T. s. pernambucensis" in north-east Brazil (Pernambuco and Alagoas), and "T. s. solitarius" found in south-east Paraguay and extreme north-east Argentina. The former, however, turned out to be not distinct from the nominate but rather individual birds that showed a particular color morph which is now known to also occur elsewhere. Notably, the hue of the back varies between olive and rusty, and the intensity of the lower neck's plumage color also varies. The black barring in these areas is more or less strong. "pernambucensis" refers to yellower birds with much barring, especially on the neck.
Solitary tinamou
9768438#1
The Bartlett's tinamou is a monotypic species. All tinamou are from the family Tinamidae, and in the larger scheme are also ratites. Unlike other ratites, tinamous can fly, although in general, they are not strong fliers. All ratites evolved from prehistoric flying birds, and tinamous are the closest living relative of these birds.
Bartlett's tinamou
206410#5
The wings of all rails are short and rounded. The flight of those Rallidae able to fly, while not powerful, can be sustained for long periods of time, and many species migrate annually. The weakness of their flight, however, means they are easily blown off course, thus are common vagrants, a characteristic that has led them to colonize many isolated oceanic islands. Furthermore, these birds often prefer to run rather than fly, especially in dense habitat. Some are also flightless at some time during their moult periods.
Rail (bird)
9685211#1
This is a monotypic species. All tinamou are from the family Tinamidae, and in the larger scheme are also ratites. Unlike other ratites, tinamous can fly, although in general, they are not strong fliers. All ratites evolved from prehistoric flying birds, and tinamous are the closest living relative of these birds.
Tepui tinamou