The biological study of animals.

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Why do pandas have a high probability of giving birth to twins?

According to the BBC documentary "Wild About Pandas", about half of panda birth result in twins. Why do they have such a high probability compared to other mammals? What factor(s) control that ...
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1answer
445 views

How can an albatross stay airborne for months?

Albatrosses, of the biological family Diomedeidae, are large seabirds allied to the procellariids, storm-petrels and diving-petrels in the order Procellariiformes. They range widely in the Southern ...
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574 views

Do other animals have different blood types?

Humans have the ABO and Rhesus blood typing systems. I have two questions about it: Why have we evolved these blood types? Do other animals have different blood types as well?
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Skull mystery on beach

The skull was found on a beach on the Sechelt inlet on Canada's pacific coast. A marine environment. What species is this skull from?
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2k views

Why does the butterfly have a cocoon stage in its life cycle?

Why does the butterfly have a cocoon stage in its life cycle? It could have simply grown up within the egg/cocoon, and emerged as a butterfly. Instead it is first an egg, then a worm, then a ...
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How best to count bees entering and leaving a hive to measure hive activity?

This is my first question here, so I apologize for all mistakes I could have possibly made. I'm a high school student in East-Central Europe and I need to complete some research for a biology contest ...
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Species with reproduction barriers that can both reproduce with a third species

To start with, I do not have a sound knowledge in biology or any formal education in the area. I was told that one of the definition of a species is a reproductive barrier, which means that if two ...
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502 views

What's the name of this bird?

This morning I saw a bird that I have never seen before. Since it was quite big, I'm very interested in knowing its name. The bird was quite big, at least 2-3 times of a common blackbird. The wings ...
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412 views

Transitivity of Species Definitions

There are many definitions of "species" which usually take the form Two individuals are of the same species if ... An implied (rarely made explicit) property of any sensible species definition ...
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112 views

What is the smallest scale at which blood vessels, nerves and other structures are deterministic?

Super simple question, but I can't find the answer on the Internet (and I'm in a foreign country so the library is not English.) As the title says, what is the smallest scale at which blood vessels, ...
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318 views

Can canines communicate with each other using gaze direction?

After researching why humans have white scleras when most primates have dark scleras, I stumbled upon the cooperative eye hypothesis. It proposed that white scleras may have evolved on behalf that it ...
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1answer
94 views

Can a lizard shed a regrown tail again?

Some lizards are famous for their ability to voluntarily shed their tail to elude predators (Autotomy). After a while, the tail will be regenerated, though with slightly different qualities, as ...
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How much energy does a lion contain? [closed]

I was looking into the following problem: Obviously, the solution lies in how much energy either can output per unit of time. The total energy output of the sun is $3.8×10^{26} \frac{J}{s}$. The ...
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2answers
984 views

What kind of beetle is this?

I live in Denmark, Europe and I found this insect wandering around in my garden the other day. It's some kind of beetle but i dont know what kind it is or the species. The beetle could also fly and ...
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2answers
365 views

What are the frequency ranges of most marine mammal vocalizations?

I am trying to determine a list of frequency ranges into which marine mammal vocalizations fall. Ideally, I would like a list showing where the most popular marine mammal vocalizations fall, followed ...
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1answer
379 views

Why does the sex of the parent species determines the species of a hybrid offspring

I've read a little about hybrid animals, and have been amazed by the fact that the sex of the parent species determine the species of the offspring, in some hybrids. A male horse and a female donkey ...
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1answer
3k views

Will the “frog in boiling water not jumping out” work on warm blooded animals

There is the famous saying about a frog that is put in water that are slowly boiling will not jump out until it's too late. I realize it happens because of the frog's cold blood that adjusts to the ...
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1answer
237 views

What is the convention for log notation in biology?

I'm reading through some oldish (1980s) papers on length-weight relationships in fish and crustaceans. Many report log-log relationships without specifying whether this is natural log, base 10, etc. ...
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1answer
2k views

Is it true that oral sex exists in non-human animals?

For example, outside of humans, do other species of animals engage in oral sex, or any oral stimulation of others' genitals purely for pleasure, not any cleansing habits, etc.? Basically, what I am ...
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225 views

Is the squid giant axon the fastest conducting unmyelinated axon known?

The conduction velocity of the squid giant axon can reach 30 m/s. Is there any known example of an even faster conducting unmyelinated axons?
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1answer
1k views

Why are butterflies drinking blood?

According to this video, butterflies sometimes drink blood. Do they have the organs necessary to digest blood? I thought they eat only salts and nectar, which are easy to digest compared to proteins. ...
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2answers
188 views

Are there any structures in mammals that are used only by males?

There are examples of structures which only serve a purpose in females, but it seems like the opposite could also be true. Are there any structures which exist in both mammalian sexes and only serve a ...
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1answer
258 views

Are there specific features of birds that cats/small predators are attracted to?

I've recently heard a podcast, in which a professor describes one of the theories as to why we like abstract art. In his talk, he mentions an experiment with seagull chicks, in which the seagull ...
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240 views

Which organism has the sharpest vision?

Which organism has the sharpest vision in terms of distance and spectrum. Please propose any other useful measure.
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157 views

Does artificial high intensity light damage permanently dark ecosystems?

Popular science features on wildlife typically capture camera images using natural light, or high-speed exposures. This is not possible where the ambient light is extremely poor. E.g. Caves, Undersea ...
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275 views

Why do animal teeth get darker if exposed?

I was wondering why the teeth of cats (And dogs, as far as I know, plus possibly some other animals or even humans) get darker if they are exposed to air / light? Example: (See the lower end of ...
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Why don't rats have a gallbladder, unlike other rodents?

It has long been known that rats do not have a gallbladder, though other species including humans, monkeys, cows, reptiles, dogs and mice, all have a gallbladder. In this paper from almost 100 years ...
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Can a human acquire a memory of an animal? [closed]

I would like to know if it's possible for a human to acquire an animal memory. I mean, animals store their memories in their brain, right? And so do we, humans, store our memory. So, is it possible ...
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5answers
380 views

Theoretically, is domestication of (virtually) any animal possible?

Looking at ones that manage well alongside us human animals, such as dogs and cats, we see that this is possible for evolved, distant animals to have heritable, preferable traits around people. ...
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Why animals can move and plants cannot in general?

To clarify, I think the answer should be able to explain: What are animals? What are plants? What's the difference between animals and plants (How do biologists differentiate them, if they ...
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1answer
81 views

Cockroach-like insect identification

I just saw an insect in my room, and I have never seen anything like it ever before. I captured a photo, please see if you can identify it. It has got quite unique colours on its exodermis and it has ...
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3answers
143 views

Do any amphibians start their lives on land?

Most amphibians - at least, all the ones I know of - start their lives in the water (at least, after they hatch). They then spend time maturing before venturing onto land, where they can breed. The ...
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1answer
360 views

Regarding the kingdom Animalia, which phylogenic tree is more common: Molecular Comparisons or Body-Plan Grades

In the picture below, which I obviously do not own: it depicts two different phylogenic trees, one which is based on molecular comparisons and another one which is based on body-plan grades. My ...
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Do any animals other than humans undergo menopause?

Do any animals other than humans undergo menopause? Also, is there any difference between animals in captivity and animals in the wild as regards menopause? For example, even if menopause has been ...
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Why do rabbits often have white hindquarters?

There are several species of herbivores that have a very visible white hindquarters: several kinds of deer, rabbits, antelopes, etc. Does the white fur serve a functional purpose, or is it purely ...
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1answer
535 views

What is this crow eating, and is it a common part of the corvid diet?

Here's a picture (by Rob Curtis) of a crow carrying and eating the corpse of what looks a bit like a small hawk or falcon: Other pictures clearly show the crow is eating the dead bird. This image ...
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Why is it that cats can jump so high for their size, compared with humans?

My cat is about 1' high at the shoulder, and I am a little over 6', but my cat can easily jump onto something as high as I am. That is 6x it's height. If a cat can do this, then Why can't I jump up ...
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343 views

What is this insect I found in Russia?

I found this in Russia. It is approximately 2cm long.
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140 views

Identify this caterpillar

Could anyone try to help identify this caterpillar, there are loads of them all over my garden and I've got three of them in a makeshift caterpillar house. I've had them for about a week and they've ...
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2answers
837 views

Why is Portuguese man o' war considered a colony?

The wikipedia entry on the Portuguese man o' war says: ... the Portuguese man o' war is ... not actually a single multicellular organism but a colonial organism made up of many highly specialized ...
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694 views

Why is blood pressure higher the more distal an artery is?

Why is blood pressure generally higher in more distal arteries?
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105 views

Would a colony with only one male and female collapse?

This is a thought experiment: If we form a population with only a single founder pair, can this population survive? What would happen? Would this inbreeding cause the population to go extinct? Could ...
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1answer
968 views

How strong is spider silk?

Spider silk is pretty darn strong and all sorts of comparisons are made to steel. I'm more curious about the various moduli of spider silk and how it compares to other materials. What is the Young's ...
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1answer
502 views

Do non-human animals suffer from insomnia?

And how do we know whether they do or not? § If sleep is a physiological need, it seems weird that we become unable to fulfill on demand even in the absence of any obvious physical issues. We would ...
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1answer
743 views

What will happen if a scorpion pierces itself?

If a scorpion pierces itself, will it die or immune to its poison? If it produces the venom its blood should be immune to itself poison.
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1answer
101 views

Predators faking to be not hungry?

I believe that there are predator/prey combinations where the prey can easily spot that the predator is not hungry and will not try to flee from it. I’m thinking, for example, of gazelles who will ...
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1answer
73 views

Is the number of legs in myriapoda determined entirely by the genome?

Myriapoda (comprising, among others, millipedes and centipedes) can have hundreds of legs (Illacme plenipes having up to 750 legs). Interestingly, the number of legs (or leg pairs) appears to differ ...
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1answer
168 views

Dogs bark at familiar person in Santa costume. Why? Don't dogs trust smell over vision?

Last night 10 humans and 2 dogs spent Christmas together. At some point, one human dissappears for a few minutes and comes back wearing a full Santa outfit. Upon respawning, the dogs start barking ...
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If I put a cup over a spider, and leave it there for a day, will the spider survive?

Will it travel more slowly since it hasn't had food for a day? What if I left the cup there for longer?
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What is this bug?

I recorded a video of this bug: https://youtu.be/0eoWfHLEo7A I counted 8 legs, the front legs are a little curved. The drawing on the flat back is dark and looks like the image of Jesus with some ...