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32

They have mental maps of landmarks, which they use as well as "compass" cues: ... experienced birds can accurately complete their memorized routes by using landmarks alone. Nevertheless, we also find that route following is often consistently offset in the expected compass direction, faithfully reproducing the shape of the track, but in parallel. ...


27

Birds may indeed digest seeds under conditions of rest. It has been postulated that almost all current knowledge on mechanisms of internal seed dispersal has been obtained from experiments with resting animals. A study with the mallard Anas platyrhynchos (common wild duck), claimed to be quantitatively one of the most important seed dispersing animals in ...


19

The question is all about nomenclature (and a little bit of semantics). One can call reptiles whatever (s)he wants. The question is what do we define as being a reptile? And the answer is that there are two possible definitions, a common "bad" definition (Definition 1) and a phylogenetic-based "good" definition (definition 2). I think your confusion comes ...


18

Yes, mantises hunt cicadas... Mantis eating cicada. Source: Dreamstime. ...and yes, orioles hunt cicadas too... Oriole eating cicada. Source: Bird Ecology Study Group. .., and what may be more relevant to your idiom: orioles prey on mantises. Oriole eating mantis. Source: Sustainable Adventure.


16

I just weighed a pigeon tail feather (~10 cm) long. The mass was 0.05 g. Although all tail feathers are not equal in length (and all pigeons are not equal in size), this is probably a good approximation. Measuring the drag coefficient is going to be very challenging, because it will vary with the orientation of the oncoming airflow. A feather falling with ...


16

Short answer Birds emit infrared. Background Objects with a temperature higher than the background emit detectable infrared (IR). Endothermic (warmblooded) animals keep their body temperatures at around 37oC and given the relatively cool temperatures at the earth's surface, endotherms generally emit more IR than the background. Endothermic animals include ...


13

We really don't know - we can't really ask the chicken. At least, it's unlikely it's as painful as it can be with humans. The reason human birth is (or can be) very painful is that the human baby's head has to fit through the woman's pelvis. Since splitting from chimpanzees, human heads have gotten bigger, while the pelvis has gotten more narrow due to ...


11

This phenomenon is called tonic immobility. And those speculations you've mentioned are wrong: they do get back on their feet, only remain in that state for a prolonged time, which depends on the distance and eye contact with whoever laid the chicken on its back, as stated here. From this experiment, it can be concluded, that this behavior in which the ...


5

The forward thrusting movement so peculiar of pigeons and other fowl (Fig. 1) while walking is thought to be related to shifting the visual field. The less visible backward motion of the head is thought to be related to fixating the field of view (Dunlap & Mowler (1931). According to the meticulous observational study by Dunlap & Mowler (1931), ...


5

I think your identification is correct - this is a juvenile Common buzzard (Buteo buteo), which have a lighter coat than the grown-up birds. See this image (from here), which also shows a juvenile bird:


5

The "white-cheeked" geese have long been subject to taxonomic controversy. From the 1920s to the 1950s, authorities have classified them into between one and four species. Although Aldrich in 1946 asserted there was near-unanimous agreement among Arctic biologists that there were two species, from the 1950s Delacour's taxonomy was most often followed, which ...


5

Based on the location and picture I believe this a Spotted Sandpiper (Actitis macularis) chick. Once they hatch, they are out of the nest, the one you are holding looks fairly small still, must have hatched recently. You can find more information about them here.


4

First of all, dinosaurs did not evolve to birds. A better way of saying it is that modern birds evolved from a particular type of dinosaur. That, however, is not the same as the blanket statement "dinosaurs evolved to birds". The latter implies that dinosaurs somehow morphed into birds and stopped being dinosaurs. What actually happens is that a species ...


4

Hummingbirds were not created, they evolved. Ancestors of a modern species need not be that morphologically different from their progeny, even over a time span of millions of years. And organism will fill a niche based on its fitness to survive in the niche. If there are strong selective pressures in the environment to maintain the traits that we see ...


4

The accepted answer doesn't point out that you can get the answer straight from the AOU if you have access to a science library: they publish explanations of changes to the AOU Checklist in The Auk! The one involving Branta hutchinsii is from Banks et al. 2004; the exact text they use are: pp. 59–60. Several genetic studies of geese, including recent ...


3

Common Buzzard, Buteo buteo Belonging to the Accipitridae family, which consists of ~32 birds of prey in Europe, Buteo buteo is a fairly common bird of prey through much of Europe. Resident up to Northern limits of approximately Britain, Denmark, southern Sweden, Northern Germany, Poland, Belarus, and Ukraine, and through to the Southern limits of Europe. ...


3

Welcome to Biology.SE. Did you say warm-blooded? The term warm-blood is very unclear. The correct terms are endo-, exo-, poikilo- and homeo- therm. In short… Source of heat endo = inside exo = outside Variation in inside temperature Poikilo = varies homeo = does not vary Any combination of these two axes exist. For example: If the ...


3

Dinosaurs is a very broad term which includes both the ancestors of birds as well as modern reptiles. But that analogy stretches as far to say that a bird is a modern dinosaur and a reptile is a modern dinosaur but a bird is not a reptile. Both of their ancestors lived during the cretaceous period and tend to get lumped together. Another analogy would be ...


2

So, we typically think about migrating birds as living somewhere (North) and then traveling South for the winter. This way of thinking is actually not accurate according to a number of ornithologists, including many I used to work with/for. Thy suggest that the birds live in the South and migrate North to breed and to avoid overcrowding of Southern locales. ...


2

Birds find their niches based on many reasons. Their choice is based on primarily resource availability, predation risk, and competition. Keep in mind there are variations among species, most birds like to forage for food at a hight safe enough to avoid ground predation, at the same time to be able to see and find food without much competition. Therefore ...


2

The technology is not there (yet) for deployments on 10 gram birds. The limits for GPS technology are around the 50 g range, for birds. Also bear in mind that the smallest loggers are generally not capable of transmitting, so you would need to recapture the animals to retrieve your data. As your question implies, there is a strong trade-off between device ...


1

This example proves IMHO that migration is largely nature and not nurture: In the Netherlands, white storks were bred / reintroduced. A large part (about one third?) of the reintroduced birds do not migrate, but their offspring usually does migrate see. They couldn't have learned it from their parents, that's for sure.


1

It seems as though it is named for feathers below the beak that have a barblike appearance, rather than actual barbs. It may be clearer from these images: India Nature Watch Or in this photo: SivamDesign - Flickr


1

Birds (crows inclusive) have better heat conservation adaptations as compared to humans. Some of these are (but not limited to): -Hollow tubes in feathers which provide insulation reducing heat loss. -Reduction of appendage length especially in species that dwell in cold regions. So conditions we perceive as cold are relatively warm for birds. My ...


1

There are a variety of physiological, anatomical and behavioral adaptations that keep birds warm in winter. For starters, birds are endothermic ("warm-blooded"), similar to mammals. You suggested that the coats humans wear are superior to feathers as insulation. Yet some of the finest coats and sleeping bags were long filled with feathers (e.g. goose down). ...


1

It would help knowing your location, though that would still leave a lot of guesswork. For example, did the birds KNOW it was going to be a warm winter? If a bird sensed a warm winter and chose to stay put, rather than migrate, only to be caught by a sudden freeze, the results could obviously be disastrous. A severe drought combined with dire weather ...


1

I found the same in this book, published just over 100 years ago. The book appears to be the result of some pretty rigorous study, so I expect it is a reliable source. On page 294, it refers to the gizzard as an involuntary sphincter, and again on page 302 it refers to the grinding of food in poultry as involuntary. In fact it says that because poultry ...


1

Involuntary. The gizzard, like our stomachs, works unconciously. However, chickens do choose to peck up stones to help along the process, whether that is by instinct or otherwise. (I raised chickens a long time but a proper reference is below) This book on commercial poultry raising says involuntary



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