The biological study of animals.

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What organs are absolutely needed by the human body?

The title is my question: what organs are absolutely needed (fatal if injured/removed) by the human body and perhaps animals in general? I'm not asking which organs are mechanically replaceable, but ...
2
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1answer
24 views

If crocodiles are k-selected, why do they supposedly “not age,” as in avoid senescence?

I recently saw a few sources stating that Crocodiles do not biologically age, implying negligible senescence. Basically, a 70 year old crocodile is in the same physical/health condition as a 7 year ...
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0answers
43 views

ants and their super powers [on hold]

I've noticed lots of ants being inside a package with sugar confectionery decorations. How did they get into a completely healthy package ? (P.M they ate its colors, what is left is some boring ...
7
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2answers
728 views

Are all quadrupeds edible? [closed]

I wonder if all quadrupeds (or, mammals, at least), are edible? From what I have collected, even down to fish, everything is edible apart from being sick or infected, and, apart from some glands ...
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2answers
31 views

Spatial dimensions for an animal

I'm reading a review paper. They say: The position of an object in head-centered coordinates (that is, relative to an animal's head) can be defined along three axes: the medio-lateral (radial) ...
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1answer
73 views

How much do crocodiles eat`?

How much do crocodiles eat? The closest I found to an answer was on german wikipedia, where it says that adult nile crocodiles eat "only about 50 full meals a year." While interesting, without knowing ...
7
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1answer
115 views

What species of fox is this?

I found this picture of a fox in a news article about arctic foxes in Sweden (source), but I'm not sure whether it is actually an arctic fox. On the one hand, it has white fur, which is the correct ...
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2answers
84 views

Why would a mother reject her offspring if it has been “interfered” with by humans?

There was a recent incident at Yellowstone National Park in which tourists placed a bison calf in their vehicle, and that eventually led to the calf being euthanized. The National Park Service issued ...
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0answers
14 views

ID for any of the following insects. Karnataka, India. May 2016 [closed]

Please help with the identification of the beetles/ bugs/ whatever insects they are. Thanks!
4
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1answer
58 views

Do ants use something similar to the honey bee “waggle dance” to instruct the rest of the colony where to find a food source?

In the 20 years since we built our home, we've just recently had our first ant infestation. I'm familiar with the fact that ants leave scent trails to find their way back and forth between the ...
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0answers
16 views

Do all parasitic worms lack tango receptors on their skin?

I read that the parasitic nematodes lack tango receptors on the surface of their body. Is this true for all the parasitic worms?
3
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1answer
61 views

Do animals have different taste preferences within the same species?

Humans (especially children...) seem to dislike certain foods or drinks, that other humans seem to like. Common examples are coffee, french cheeses, milk, fish and cabbage. Are there examples of ...
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1answer
52 views

What nocturnal animal sound am I hearing in the trees in Maine?

Every year, during late summer nights (usually around 9:00 pm) in Maine, I hear a noise coming from high up in the trees. The trees I hear it from are mostly maple or conifer, but where I live there ...
8
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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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0answers
28 views

What were the camels' bumps good for back in the polar areas?

I've heard that camels lived in the North America formerly and just in the last few thousands years they've migrated to the hot deserts. Thus they allegedly utilized the adaptations against the cold ...
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2answers
71 views

What is this animal? [duplicate]

Can someone tell me what is the name of this one? Then I can check a little more about it.
4
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1answer
77 views

Identification of a small mammal

Could someone help with identification of this small mammal? Is it a possum? A dormouse? It was photographed in Sukhumi botanical garden, in Abkhazia (west of Georgia, on the shores of the black ...
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1answer
30 views

How do mosquitoes orientate in the darkness?

An annoying mosquito (Culicidae) which kept me awake nearly the whole night lead me to this question. I have heard that mosquitoes can smell CO2 which could help them to orientate in the darkness, ...
6
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2answers
101 views

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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1answer
4k views

What is this crawling next to my house?

I just found this outside my house while walking the dog. I was thinking it's some kind of slug? It's been raining a lot lately and today, so maybe that has something to do with it being on the ...
7
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1answer
95 views

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 ...
12
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2answers
371 views

Why do crabs spit?

Last year I photographed this juvenile Sally Lightfoot Crab (Grapsus grapsus) 'spitting' (click for larger view): I thought I'd look up more information on this behavior, but couldn't find any ...
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0answers
27 views

Can you suggest me some books/articles about how female birds indicate receptivity to copulation? [closed]

Where can I find informations about the topic? I need to find some examples. I also really need this particular information: I know that many female mammals display lordosis behavior that indicate ...
4
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0answers
19 views

Extiction of non-mammal Synapsida

I am following M.J. Benton's Vertebrate Palaeontology, which explains how many groups of Synapsida were already extinct in the Mesozoic Era, with one obvious exception being the group of Cynodontia, ...
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Cells of Zona pellucida

My textbook states: Blastocyst hatches out by lysis of Zona pellucida with the help of the enzyme strypsin, Later the cells of Zona pellucida gradually disappear. We know that Zona pellucida is ...
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0answers
9 views

What did William Harvey discover from experimenting with deer?

On his wikipedia page, I read the following: In particular, Charles' hunting expeditions gave Harvey access to many deer carcasses; it was upon them that Harvey made many observations and ...
3
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1answer
19 views

What is the Cordil that Edward Topsell describes?

In his "History of four-footed beasts and serpents", Edward Topsell describes a "serpent" called Cordil. Since he lists everything that crawls on the ground as a serpent, regardless of being a ...
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0answers
17 views

Is it legal to send animals for near spaceflight research? [migrated]

For biology purposes, is it legal or not, like using crickets and mouse as subjects to be sent near space (Upper Stratosphere) High Altitude Balloon
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5answers
2k views

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 ...
6
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2answers
341 views

Do animals exist which have great vision, but see only grayscale?

In computer vision the color information is often discarded, as most object recognition tasks seem to work just as well on the greyscale image (even better, because there is less unnecessary ...
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0answers
22 views

Body part in motion after decapitation?

I'm sure following video is totally different than of other mammal after their body parts decapitated. In this video apparently, the snake is cut into three pieces. But when we look closer to the ...
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3answers
144 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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0answers
35 views

Are there insects who can or try to avoid colliding with raindrops?

Some insects are very fast. Does this mean that they are capable of finding a way through falling raindrops without getting wet? Probably they don't do that at all, because riding on a bike or in a ...
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1answer
95 views

Can kit foxes and red foxes produce offspring?

Can a kit fox (Vulpes macrotis) and a red fox (Vulpes vulpes) together produce offspring? Would such a hybrid be fertile?
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2answers
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Who are humans' closest relatives, after primates?

This question here addresses the controversy of whether humans are more closely related to bonobos or chimps. My question is - which group of animals are are closest relatives, beyond primates? Or ...
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2answers
276 views

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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1answer
47 views

Do camels have nucleated RBCs or enucleated RBCs?

Most mammals have enucleated RBCs as an adaptation to facilitate the transport of oxygen. My text says that camels and llamas are exceptions to these. I was wondering why they are exceptions, and the ...
6
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2answers
524 views

What makes an animal/species suitable for domestication/training?

Humans have domesticated all manner of creatures during the course of their civilization - dogs, horses, several types of cattle, varieties of birds, and perhaps others too. A prerequisite for an ...
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3answers
297 views

What is called the “area size that an animal usually lives in”?

What is called the "area size that an animal usually lives in" or "needs for a normal life"? Is there any specific term?
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1answer
20 views

How many cells does the hermaphrodite version of Caenorhabditis elegans have? [closed]

Wikipedia states: The male C. elegans, for example, has 1031 cells How many cells does the female version have?
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1answer
36 views

How to compare diversity between different ecosystems?

I've used the Shannon Wiener Diversity Index for a single ecosystem (species as categorical variables). Do you know any alternative indices, especially ones that compare diversity between different ...
3
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1answer
89 views

Has the human body the greatest total length of nerves of all animals?

I've read that a human body contains about 150,000-180,000 km (Pakkenberg et al., 1997; 2003) of nerve wiring in the whole body. But does this length increase with the size of the animal? For example, ...
4
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1answer
88 views

Species identification - greenish blue ocean worm (nudibranch?) in Perhentian Islands, Malaysia

We found this on a beach at the Perhentian Islands, Malaysia in March, 2016 and cannot identify it. It's some sort of worm-type creature with many legs and bluish back about 15cm long. The legs ...
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1answer
30 views

What do red ants secrete while marching in a line, one after the other?

Red ants often move in a group, and seem to follow a trail one after the other. Once, I rubbed a part of the path along which they were moving and surprisingly found that the successive ants roaming ...
12
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1answer
6k views

How many mice are on the Earth?

We are 7 billion human beings on the Earth. But how many mice are there? How would you estimate such a number?
11
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3answers
590 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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1answer
51 views

What are these curious cetaceans?

At the beginning of the superb documentary film “Un jardin d’Eden sous les mers” (“A garden of Eden under the seas”) [1], we see a group of curious cetaceans. At about 1 min. What are these ...
34
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2answers
3k views

Do homing pigeons fly straight home or follow certain “highways”?

Homing pigeons (Columba livia) have been prized for their navigational abilities for thousands of years. They’ve served as messengers during war, as a means of long-distance communication, and as ...
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1answer
92 views

What happens to a snail if we cut off its antennae?

First off, I don't know why snails have antennas. Are they eyes? And what if we cut those antennae off? If they are like eyes, could a blind snail survive somehow?
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1answer
141 views

What is the scientific and common name of this bug?

Captured this under my stereo microscope. Much beautiful than appearing on my camera sensor. Can someone help me identify it and explore more? Also is it having a compound eye ? Location: New ...