The biological study of animals.

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Why would villagers attack Orangutans?

I read today in the news that villagers in Borneo were attacking refugee Orangutans. Why would they do this?
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Which metazoans host anaerobes to aid in digestion? Do any host oxic digestive tracts?

Many metazoans (e.g., mammals, insects, earthworms) have anoxic digestive tracts that are colonized by anaerobic microbes that perform portions of digestion of food for the host. Some other metazoans ...
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Is pathlength correction vital to be included while quantifying protein

I am trying to quantify protein in serum/plasma samples. I have carried out biuret assay for my samples using microplate reader. While performing I encountered the doubt whether I should include ...
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Do other primates get gallstones?

Which non-human primates actually get gall stones the same as humans? All, some, none? References appreciated! Anecdotes about pet primates with gallstones also welcome if you have any...
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2answers
3k views

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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Steppe peoples method for healing horses' wounds

There was a custom among nomadic steppe peoples like Huns or Mongols of putting pieces of saltened meat in wounds of their horses to make them heal faster. Did it work? If so, how? I suppose it has ...
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4answers
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Why do men have nipples?

I'd be tempted to call nipples in men vestigial, but that suggests they have no modern function. They do have a function, of course, but only in women. So why do men (and all male mammals) have them?
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44 views

How can birds keep their eyes moist during flight? [duplicate]

Mammals have an upper lid and small mass of tissue in the upper corner known as nictitating membrane. This helps keep the eyes clean; birds can moisten their eyes in flight using this membrane ...
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101 views

Which class of animals constitute the largest biomass?

I found here that species-wise it is cow. But, collectively, insects may exceed even mammals. So, which class of animals constitutes the largest biomass?
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102 views

Please identify organ

This is the gut area of an Eastern Grey Kangaroo taken of a property in the Southern Highlands of NSW, Australia. The top red organ appears to be the spleen but what is the elongated tubular organ ...
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1answer
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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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3answers
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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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773 views

Why are lions the only social cats?

We know that almost all cats are solitary. How did the Lions (Panthera leo) end up social animals? Do we have an explanatory evolutionary path describing how the Lions became social while the rest of ...
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427 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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Is lung size/shape a factor in long-continuous running of animals?

Apart from other factors, does lung shape/structure/size play any role in long-continuous running animals. Is there any similarity in lung structure between different long-continuous running species?
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1answer
697 views

What is the known maximum ranging distance of a bat's sonar?

Bats are known to navigate by using echo-location. How far away can a bat detect an object by its sonar?
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1answer
128 views

Are there fishes with a double circulatory system?

Our courseware materials say there are such fishes, but my Internet searches suggests fishes only have a single circulatory system.
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429 views

What kind of bird species is this?

Every now and then I got a glimpse of this bird which I'm pretty sure is not native to Northern Germany where I live. There are at least three of these birds around but I usually only see something ...
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2answers
451 views

Why Egg shell is not called a cell wall?

Egg is a single cell and has a outer hard covering outside inside which there is a cell membrane. Then why isn't the egg shell a cell wall? Is it because no exchange of materials take place through ...
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1answer
134 views

The biggest underground living animal

It's easy to find informations about the biggest animals at land / at sea / in the air. But what was the biggest animal that ever existed, that lives underground? No animals that were forced to live ...
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1answer
6k views

Why do we grow so much hair on our heads compared to our bodies?

I've been wondering about head hair, facial hair in particular. Human males can grow very extensive beards should they choose to not shave - however you do not really see this in our chimpanzee ...
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290 views

is a musk deer's musk pod in its abdomen, its back, or its bottom/rear end?

I have read/heard different things about where a musk deer stores its perfume Some links say it stores it in its abdomen just in front of its penis. Others say the rectum(by which I suppose they ...
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51 views

Was this snake behaving abnormally?

This morning, I walked out front of my house to find a medium-sized snake balled up on my driveway beneath my motorcycle. I spotted it from my porch so I didn't walk any closer. I believe it was a ...
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4answers
11k views

Why we have no enzyme to digest cellulose?

As we know, cellulose is the most abundant polysaccharide in nature. Why don't we have any enzyme to digest cellulose?
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45 views

Biological Evolution outside of Earth [closed]

What drives evolution forward? I heard that climate change drives species to evolve and adapt. Is there any other mechanism that is encoded in our DNA by which species can over abrupt changes, evolve ...
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1answer
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Endothermy in different species

Birds and mammals are both endothermic, meaning they metabolically generate the heat they need to keep their body within a certain temperature ranger. But birds are closer relatives to reptiles than ...
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Why do I often see male robins with female robins?

Even when it is not breeding season for robins I still often see male robins with female robins. But why? I know that the male robin often chirps to find female robins within his territory. I also ...
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2answers
54 views

Do any predatorial animals attempt to appear smaller?

There are many animals that have behaviors or characteristics to make themselves appear larger than they are as a defense mechanism, such as butterflies have large eye patterns on their wings. Are ...
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1answer
81 views

Do all mammals have a Ventricular system?

I am familiar with the human Ventricular system that circulates Cerebrospinal fluid. This is needed among other reasons, to suspend the heavy human brain, and for injury protection. Do all mammals ...
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431 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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2answers
130 views

Which primates can swim underwater?

I saw a documentary awhile back and they were profiling a certain species of monkey which regularly swims underwater. I can't recall which species it was but they said it was rare for primates to do ...
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1answer
111 views

What type of jellyfish is this

I have been swimming in the seas around Minorca and saw a jellyfish I had not seen before. I have tried to find it and have (eventually) found 1 single picture of the jellyfish. The problem I ...
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How much oil you can get from a dead animal

This is purely speculative, but is there a formula to calculate how much oil you can get from 1 Kg of biomass? I've seen bioreactors in farms where they put dung, vegetable scraps, and all bio scraps,...
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3answers
172 views

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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can the regeneration mechanism be used in humans that of lizards?

how lizards grow their tail again like is there any mechanism or specific protein which helps them to regrow their tail? can the mechanism of regeneration be used in humans to regenerate our limbs is ...
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125 views

How to know the gestation time of pregnant mice?

In lab mice I wish to establish how many weeks my animals are into their pregnancy. Is there some way?
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3k views

Why do people and animals stretch out their bodies and what is causing this behaviour?

I noticed that my cat which is only 6 months old has started stretching its body from time to time. Then I thought that this motion doesn't seem very natural from another cat's viewpoint, so my cat ...
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3answers
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What's the difference between a plant and an animal?

Are there some living things where the distinction between plant and animal is blurry or unclear? I wouldn't know where to put something like yeast. I also thought of photosynthesis, but then I ...
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2answers
171 views

Is it possible to pet/groom birds?

I wonder if it's possible to pet a domestic crow, or an owl. Do birds respond to grooming as cats or dogs, for example? If so, then how does one pet a bird?
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How octopus develops its imitation skill?

I've watched one documentary about a Mimic octopus which they can imitate another animals in several form e.g. a Lion fish, a Sea snake, a Flatfish, etc. My question is how these octopuses can have ...
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1answer
169 views

The heart of a Pigmy Shrew beats 1300 per minute then why is it so fast?

A pigmy shrew is such small animal. Even with such fast heart beat their average life span is 1.5 years. So can we consider faster heartbeat not good for health?
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3answers
288 views

Insect identification: white spotted beetle

3 pairs of legs, a pair of antenna, wings absent, compound eye, 4-6 centimeter approx. in size. I found this beetle at my door, in Pune, India.
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1answer
280 views

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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What insect is in this photo?

Found in Russia, in the kitchen. It is about 1–2 cm length.
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1answer
348 views

What kind of caterpillar is this?

I've made a photo using the reversed 58 mm lens and my cropped DSLR: Could you please help? I really don't know where this came from. I found it in Russia.
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Madrid, Noise by the river: Bird or cricket?

I currently live in Madrid, Spain. In July there was a loud animal near the river, in an out of town area surrounded by grassland, with trees along the river. It's continued into August, though it ...
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1answer
66 views

Are dogs affected by dwarfism?

My husband and I noticed a dog today that looked like a smaller version of a purebred Border Collie, although it didn't appear to be a puppy. It made us wonder if other animal species experience ...
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How do animals end up in remote areas?

I was thinking specifically about random marshy water holes on farmers fields. It seems that you can visit just about any one of these and you will find frogs if you look hard enough. They usually ...
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Is there a mechanism by which mammals lose interest in a partner after mating?

I'm reading the book called "Cupid's poison arrow", which revolves around a rather simple assumption: most mammals, including humans have a genetic program that is responsible for ever increasing ...