Tag Info

Hot answers tagged

33

Birds are both flying dinosaurs and flying reptiles. Yes, that's potentially confusing. To understand the apparent contradiction, you have to understand how modern classification of organisms works (phylogenetic systematics). Under the old (Linnean) classification system, Reptilia (reptiles) was an order and Aves (birds) was a separate order. Phylogenetic ...


19

The joint you are thinking (I assume) of is not a knee, nor is it an elbow, instead it is an ankle which is bending the same way as us humans. You can see from the below diagram that the knee - the joint between the femur and tibia - is just further up the leg normally hidden by feathers. Birds have a comparatively elongated metatarsus which gives the ...


15

In addition to kmm's excellent answer, I'd like to present the xkcd point of view.


12

Various features of brain,skull and beak anatomy help to achieve protection. A paper was published in PLoSOne in 2011 on this very topic: Why do woodpeckers resist head impact injury: a biomechanical investigation There is also a very readable summary on the BBC website. I advise that you read the whole article, but here is a quotation which lists the ...


12

I looked up winglets so I had context for this answer. I'm interpreting winglets as the vertical tips at the end of airplane wings. If so, then you are correct. The spread primary feathers of soaring birds like eagles function as winglets (Tucker 1993). Airbus has a biomimicry web page devoted to some of the biological designs, including winglets, they ...


11

This looks pretty much like a female zebra finch to me (the male have a more prominent feather pattern). See this picture: These birds are not native in Europe, this is correct. But it is always possible that birds escape captivity (or are released) and the live in countries where they originally not belong. I think this is the case with the zebra finch ...


10

This is a Cattle Egret (Bubulcus ibis), which is a heron in its breeding plumage. When not breeding, the bird is white. See the images for comparision: Breeding cattle egret with colored feathers. Nonbreeding cattle egret, completely white.


8

Definitions of adaptation Unfortunately, there is not such thing as a single, standard definition of adaptation. But for most cases the accurate definition the author is using is not of much importance as all of the usual definitions totally fit in the sentence without changing the meaning of the concept they want to express. In you case however, the ...


8

The logical assertion "winglets have not happened in a long time, therefore they are not advantageous" is incorrect. It is possible for an advantageous trait not to evolve even when advantageous, if there is no "path" to it. The trait only occurs gradually, in small incremental steps. If intermediary steps are harmful, the trait will not occur, even if the ...


7

All animals develop in this way, whether they are oviparous (developing in an egg) or viviparous (developing inside their mother, or live-birth). From Wild Birds Unlimited: All mammals have navels or belly buttons where the umbilical cord distributes nutrients between a mother and her fetus. After birth, the umbilical cord is cut and a scar develops ...


7

There are two possibilites with evolutionary processes: The development either never went into this direction or it brought no advantages. Besides this two possibilities the claims from the other forum are wrong. Birds (not all of them though) do have winglet-like structures. If you look at big birds, you can see feathers on the end of the wings looking like ...


6

There is a classification of birds called Soaring birds. Soaring Birds In definition, some land birds, such as vultures and certain hawks, sustain flight for long periods without flapping their wings. They take advantage of updrafts produced when the wind blows over hills and mountain ridges or make use of rising columns of warm air called ...


6

Gibson (2006) identified three characteristics that help woodpeckers avoid brain injury: their small size, which reduces the stress on the brain for a given acceleration the short duration of the impact, which increases the tolerable acceleration the orientation of the brain within the skull, which increases the area of contact between the ...


6

On a more general level it is possible for parents to influence sex-ratio of broods in a number of ways, and there are other reasons why a brood might have a sex ratio distortion. The paper I've been reading this morning is about side-blotched lizards doing just this. I'll give a quick basic answer just from the top of my head and hopefully someone can give ...


6

I'm not an expert, but I think that you have to be specific about the flying animals to which you are referring. Pterosaurs are not classed as dinosaurs, whereas modern birds are descended from theropod dinosaurs which is where feathers appeared.


6

This is a pond heron or paddy bird. The de-facto source for identifying Indian birds is Birds of the Indian Subcontinent by Richard Grimmett, Carol Inskipp and Tim Inskipp. The book is remarkably complete and contains the vast majority of species found in the Indian Subcontinent.


6

Obviously, as you point out, some birds, such as waterbirds (ducks, puffins, auks, sandpipers) are perfectly fine in the rain, as they spend much of their time in the water anyhow and have oil glands that waterproof their feathers. For other birds, rain can increase heat loss. For instance, rain increases metabolism by up to 22% in eagles (Stalmaster & ...


5

I bet you'll be interested about the concept monophyly. Any human-made group of species (or taxon) like birds dinosaurs, primate, bacteria, angiosperm, reptiles, … are either monophyletic, polyphyletic or paraphyletic. This picture explain the concept When the taxon is monophyletic it is called a clade. Monophyletic taxon are those groups of species that ...


5

For me it looks like a Malayan Night Heron, Gorsachius melanolophus. They seems to be common in this part of Asia, see the distribution. It looks strange because he probably get scared.


5

It's a Black Crowned Night Heron, Nycticorax nycticorax, in my opinion - you can read more about it here. Key to it's identification is the shape of the body and bill, it's characteristic of species from the heron family such as the green heron. The range is right and the red eye is a good clue too.


5

Your questions mean basically the same. Birdcare.com says: The situation in which all the eggs in a clutch do not hatch at (more or less) the same time, as is more usual among birds, but have their hatching spread over several days. It is well seen in the various types of raptor, and is an adaptation to a type of food supply which may fluctuate. During ...


5

This is a story I have been told as well when I was a kid. Usually this is related to the foreign smell that the humans leave on the chick. However, this seems to be an urban legend, as birds have not a great sense of smell. Snopes says about this: However, Mother birds will not reject their babies because they smell human scent on them, nor will ...


5

Most species of birds have 2 foveas, the temporal fovea and the central fovea. temporal fovea, which is like ours in the sense that it looks straight ahead and offers binocular vision (i.e. the temporal foveas of both eyes point in the same direction). But birds also have a central fovea, which points sideways and is, obviously, monocular (i.e., ...


4

A trait is said to be adaptive when it causes fitness to increase. Fitness is generally understood as the (relative) contribution to future generations in terms of offspring or genes. The trait is selected for by the environment and hence increases fitness. In the paper of Dey et al. this is the fitness of the parent birds. Hatching asynchrony causes size ...


4

As per Wikipedia it is listed as endangered having been downgraded from critically endangered due to the spread in sightings over the years over a large area. Sightings have been rare with a reported sighting on 12th April 2005 and a dead specimen found in 2006 The first photos and a 17 second video of the bird was taken by a wildlife photographer John Young ...


4

Cant be very sure about ravens but the maximum recorded flight duration is of Alpine Swift — 6 months. Pigeons can fly up to 1800km in a long flight. From this article: In the United States, the longest pigeon races involve flights of 1800 km and, because substantial financial rewards accrue to the owner of the fastest pigeon, there is severe ...


3

In short; yes. It depends on the breed (not all lay up to 1 egg/day), the age of the bird and on nutrition. High yielding breeds of chicken are e.g. dependent on supplements of calcium to be able to produce new shells rapidly (e.g. in the form of ground-up shells). Some information on the nutrient requirements of chicken can be found at Feeding the Laying ...


3

From the article titled "Evidence of mutualistic synzoochory between cryptogams and hummingbirds", the specific advantage for the hummingbird is that it gets good nest building material through the selection of cryptograms. The cryptograms though have its seeds dispersed over large distances by birds which is a process called synzoochory.


3

I'd go with juvenile striated heron. I ruled out others such as the chinese pond heron because of the spotted wing plumage and slightly different shape of the patch around the eye. The night heron seems to have a more red eye than the striated heron and appears to have a stubbier beak. Arkive is a good place to see a lot of pictures of birds, this is a good ...


3

It seems like they are not affected by fluorescent light frequency. I did not find anything about their visual sampling rate. Their hearing is between 0-200Hz with an average of 86Hz so I guess the visual sampling rate is under this, but that's just a guess. We conclude that at the illumination levels used in this experiment, the hens did not perceive ...



Only top voted, non community-wiki answers of a minimum length are eligible