The biological study of animals.

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Are there any other animals that become attached to a non-living object?

Do any animals become psychologically attached to any non-living object that is not useful to the animal for any of its physical needs, like some children do to stuffed animals? Some children are so ...
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Is it theoretically possible to restore the Tiger population to 100,000?

The current global Tiger population is roughly 5100 according to Wikipedia. With habitat destruction and poaching continuing and no effective improvement in conservation, most likely the Tiger ...
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Help Needed Identifying Corvids

I'd appreciate some help identifying these three corvids I photographed in Austria during the Summer: I know identifying corvids can be difficult, I'm not an ornithologist, just an amateur bird ...
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Is the theory of evolution being disproved by bats?

For some species the Darwin's theory evolution makes perfect sense. I can easily imagine how, for example, the giraffe has evolved to its current appearance: the natural selection was favoring ...
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Laying eggs vs giving birth: is there a connection with internal vs. external ears?

I have heard that "The animals who have their 'EARS' outside their body give birth to their young ones and the animals who have their 'EARS' inside their body lay eggs." Is this true? Are there ...
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Do male animals visually perceive females as more/less attractive?

If we somehow remove pheromones, do animals experience a phenomenon similar to human "visual beauty" when looking at members of the opposite sex? For example, given a set of 20 female ducks observed ...
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407 views

What medical and commercial proteins are made using genetically modified animals?

Recombinant technologies in micro-organisms being used to produce commercial and medically useful proteins like insulin are fairly common. However some proteins are still produced commercially in ...
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410 views

Why are there ecosystems?

Why would things self-organize in such a manner? I'm a mathematician and I have no baggage in ecology or biology. If the question is too broad maybe someone can point me to formal sources where this ...
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Why do some animals have 8 Limbs (e.g. Spiders, Octopuses)?

Octopuses have 8 tentacles, spiders have 8 legs. Is there something special about 8? It seems like an animal that needs 360° mobility has 8 legs.
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Do octopuses have better eyes than humans?

I've read that unlike humans, octopuses have eyes "designed" the "right way", i.e. with the nerve fibers behind the retina, thus getting rid of the blind spot we humans have as well as theoretically ...
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565 views

What did pangolin scales evolve from?

Were they developed anew or a heritage from fish?
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Are fish and reptilian scales homologous?

Wikipedia: Fish scales are dermally derived, specifically in the mesoderm. This fact distinguishes them from reptile scales paleontologically. So aren't reptilia scales also dermally derived?
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The least complex animals with ability to dream

People can dream, dogs can dream, cats probably too when they are sleeping. What about other creatures? Can a bird dream? Do rats have dreams? Are there any studies about that kind of thing? What ...
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271 views

What limits the size of fish compared to marine mammals?

The largest extant fish species is the whale shark (Rhincodon typus). With a length of 13 meters and a mass of about 20-30 metric tons, the whale shark is relatively small compared to the largest ...
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253 views

Why would deer continue to cross a river full of crocodiles even though some of them have been killed?

I recently watched a clip on Discovery Channel, where I saw deer crossing a river full of crocodiles, ignoring the fact that some of them would have been killed doing so. Is there a possible ...
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191 views

What is a subspecies?

Within a species there may be subspecies that are named using trinomial nomenclautre. For example the Grizzly Bear, Ursus arctos horribilis is a subspecies of the Brown Bear Ursus arctos. The ...
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802 views

Help me Identify this Spider

This red spider has set up a web in my yard, in South Eastern, Texas, United States: The spider itself is about an inch long (2.5 cm), and is predominantly red to brown in color, with red legs, and ...
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196 views

What's the smallest organism that can produce voice? [closed]

What's the smallest organism (animal, insect, or any living creature) that can produce voice. And not just make sound, but has an organ to specifically to create sound, like how us mamals have vocal ...
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223 views

Is there a DNA test to identify dog mixes?

We adopted a dog at the age of two. Our vet said it was a mix of an Australian Shepherd and Border Collie, which we've told everyone. Based on markings, I think it's likely. I am wondering, however, ...
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396 views

Are tongues red because they contain blood?

Many animals have red tongues, though not all of them - blue-tongued skinks and giraffes come to mind. Are they red because of the blood (and therefore haemoglobin) in them? It sounds plausible, but ...
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Is there any reason the common housefly continues to return to an area?

This might come off as a really silly question. But I'm wondering (especially in the case of food) if there is any reason a fly would continue to try and sit on top of a piece of food even after ...
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What evolutionary mechanism caused felines to develop purring?

And why can some felines roar while others meow?
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Which of the following lacks DNA?

a) An Enucleated ovum b) Mature RBC c) A mature spermatozoan d) Hair root According to me, there can be 2 answers, a and b because an ovum whose nucleus has been removed lacks DNA. And also, ...
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259 views

Why do small organisms make faster movements than big organisms?

I hesitated to ask this question because it seems so obvious and intuitive. However, I am not able to explain this tendency. Background It seems to me that small organisms make faster movements than ...
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Can I force evolution in a group of cells by removing all the smaller cells?

I actually have algae growing in water in a container. I was thinking if it was possible to filter the water so that all the small cells will be filtered out and only the bigger ones will remain to ...
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374 views

Do animals suffer from “Human” mental disorders?

It is tragic, but apparently Killer whales and Dolphins can commit suicide too (e.g. here)... This suggests they can become depressed. I wondered whether they were "clinically" depressed like many ...
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Is recognizing one's own mirror reflection a valid test of animal intelligence/self awareness?

I've been looking at this Ted talk on interspecies internet, and it appears that they have selected a small number of species of animals (dolphin, elephant, and some ape(?)) and are intent on ...
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Do all sea creatures that have scales have to have fins?

Do all sea creatures that have scales have to have fins? Do we know of any sea creatures that have only scales without fins? I'm especially interested in fish that have scales but no fins.
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Do dogs have something different about their physiology that allows them to pant without hyperventilating?

I was wondering this as I considered how effective panting would be for humans as a means of cooling.
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How do birds avoid mid-air collision?

Across from me there is a large flick of Pigeons and Ravens that like to nest on the roof. They swoop and dive and fly all over. Sometimes the whole flock lifts off at once. My question is, how do ...
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How are smell and taste in fish differentiated?

The senses of taste and smell in different fish classes are described as two distinct senses; smell is mediated by the nasal openings, and taste by epithelial taste buds. They are both forms of ...
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(Why) are polar bears more common in Labrador than in southern Greenland?

The Labrador Sea is between Greenland, Labrador, and Qikiqtaaluk: Map source. A Greenlandic source on polar bears states: In Greenland the polar bear lives and breeds in the northernmost parts ...
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Why are there so many sex determining systems in animals

There are several sex determining systems in animals. In mammals XY = male(except in rare cases where SRY crosses with genes on the X so that it is the reverse) and XX = female. In some birds it is ...
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How do sharks and other fish conserve and gain water in marine environments?

With the osmolarity of the average vertebrate being around 300mOsml, and salt water having an osmolarity of 1000mOsml, why does the water from the shark not leave to the salt water around it? I ...
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237 views

Is there such thing as Animal non-verbal body language?

Have there been any studies done on the animal use of their bodies to signal, communicate or express their emotions, particularly to members of other species (ex: humans)? I've been observing a very ...
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329 views

intravenous (IV) in the tail vein of an anaesthetized mouse

I trained myself to do intravenous injection on live mice. However, on anaesthetized mice you don't see the flux of your product showing that your injection was successful. In the same way, on live ...
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363 views

How fast can a panda run?

Pandas are going extinct, mostly due to habitat destruction. This leads me to the question: How fast can an average adult panda run? (more specifically Giant Panda)
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Why do snails come out after the rain?

Many times, when there is rain after a long time, snails come out afterwards, and you can see snails and slugs everywhere! I have two questions: Why do they come out after the rain? Where are they ...
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Can animals like squirrels leave “gifts” or tribute for humans?

I've heard anecdotal reports of squirrels bringing up gifts to a person's house after that person left out food for them. Sounds bizzare and unbelievable, until I actually saw some kind of a nut right ...
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What kind of insect is this and what is it doing?

I live in Denmark, Europe and found these 2 insects on a tree. I'm interested in the big fly and have the following questions: What kind of fly is it? What is it doing with the little fly?
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Identification of this Salamander

This salamander was found in a small forest pond somewhat near the Oregon coast. In the area are many rough skinned newts and a small number of another type of salamander that I still can't find the ...
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Blood clumping in mosquitos

Will a mosquito die due to blood clumping if it sucks blood from two persons having different blood group? What will happen in its gut? Is there any mechanism to avoid clumping ? Or mosquitos know ...
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381 views

Why do men grow facial hair?

Ancestral facial hair. Our closest ancestors, the chimpanzee and bonobo, both grow facial hair around the mouth area. What is noteworthy is that this is the case in both males and females of the ...
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Why do these earthworms stay between the road lines?

This article shows pictures of earthworms during floods in Texas. The worms ball up, supposedly in order to survive the floods. Can anyone explain the phenomenon a little? I can't seem to find ...
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Burns' “To a mouse” - what species of mouse?

What's the most likely mouse species Robert Burns is referring to in his poem "To a Mouse, on Turning Her Up in Her Nest with the Plough". Burns farmed near Ayr, which is on the Firth of Clyde in ...
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Evolution of spider webs?

Web making seems like a fairly complex behavior built from a pretty strong material. So how exactly did it evolve? Do we have any clues about what kind of features/behaviors preceded web making and ...
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Zoology - Help identify the kind of spider

Yesterday, I bought a banana tree (Musa Basjoo) from a local supermarket. Today, I noticed a hive of small spiders on the tree. I do not know where they came from, so I am curious to identify these ...
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What is dental health like in animals?

Do animals suffer from tooth decay, such as cavities? Is it to the same extent as in humans, or do animal teeth decay more or less? If teeth decay in animals as well, are there natural strategies ...
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Fetal development, gastrulation and embryonic disc

I am completely confused by the images circulating on the internet of human gastrulation. First, lets see how it happens in deuterostomes. This image depicts the process: (image is from Wikipedia) ...
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What traits make mountain goats so well adapted to mountain living?

I've never really understood how mountain goats manage to survive so well in mountainous regions. I've seen them scale almost sheer cliff faces with apparent ease, and they can almost sprint ...