The biological study of animals.

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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 ...
21
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3answers
361 views

How is the blood volume of a living organism measured without killing it?

How is the blood-volume of an organism measured without killing it? Note:The blood-volume of an organism is defined as the total volume of blood present inside that organism.
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0answers
28 views

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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0answers
32 views

What is the difference between pianka's index and renkonen index? [closed]

Why do Pianka's and renkonen indices give different results, even though they are both meant to measure overlap and similarities?
9
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2answers
90 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. ...
2
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2answers
40 views

Mosquito physics

What are the environmental limitations of mosquitos I should know of if I want to avoid getting bitten? For example: How fast should I walk in order to be moving too fast for one to bite me? Can a ...
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1answer
50 views

Why are Oxyuranus snake species named Taipan?

It is interesting, why are Oxyuranus species called Taipan. The snakes are Australian but taipan looks like of Chinese origin word (it means big shot - important person).
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1answer
23 views

Are there fish with a double circulatory system?

Our courseware materials say there are such fish, but the internet suggests fish only have a single circulatory system. Thanks!
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3answers
57 views

How animals know which is carnivorous and herbivorous?

Deer ran away from tiger or cheetah, but not from giraffe or zebra. where did deer learn this? How animals know which is carnivorous and herbivorous?
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0answers
47 views

Consuming animals by slaughtering vs injecting barbiturates?

In "Least painful way to die" we get an answer ... Companion animals (e.g., dogs and cats): injected barbiturates are recommended Laboratory animals (e.g., mice and rats): injected ...
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1answer
40 views

Limited space for animals - how is that bad?

I am writing an English paper wherein I have to appeal for change in the way humans treat wildlife. I was initially given a situation wherein I took a ferry in a certain area and saw a dead baby ...
8
votes
2answers
419 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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0answers
20 views

Animal counterpart to global seed vaults

Is there a global 'animal' embryo bank (or something similar to it) like the Svalbard Global Seed Vault for plant life? I don't mean 'gene' banks because they are not as 'useful' as real seeds are. A ...
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1answer
85 views

Does the DNA of a tadpole change after it becomes a frog?

Does the DNA of a tadpole change after it becomes a frog? In other words what changes take place as a tadpole becomes a frog, and does this metamorphosis affect the DNA in any way? I would appreciate ...
14
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4answers
3k views

Why do parasites sometimes kill their hosts?

It's bothered me for a while now. I understand why a parasitoid would do this, as it only temporarily requires the host, and that not all parasites kill their hosts. There seems to be no evolutionary ...
3
votes
1answer
60 views

Human bone density and Brown Bear bone density?

It is stated on this website that the density of a Grizzly bear bone is ten times our own. And since I am not into biology at all, I am confused as I don't understand the meaning of bone density here. ...
25
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1answer
2k views

Why do ants live so long?

I was surprised to learn that worker ants in some species live many years. I would have expected a lifespan of a few weeks or months (which is apparently the case for many species). What factors ...
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2answers
406 views

Did cats evolve from monkeys ? or vice versa?

Did cats evolve from monkeys ? or vice versa ? How similar are the genes of cats and monkeys ? What is the proof that they are related or that they are not related ? Most monkeys climb in trees and ...
0
votes
1answer
35 views

Do “non-human” animal like cat, dog, bird or fish think about future while sleeping? [closed]

I don't think "non-human" animal like cat, dog, bird or fish think about future while sleeping. I think when sleeping, the "non-human" animal will feel rather think about anything. I think when ...
6
votes
2answers
109 views

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 ...
10
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3answers
501 views

How many cells does the smallest animal have?

Note: question rewritten to prevent misunderstanding and make it more answerable I know that some small animals like C. elegans display surprising sophistication with a very small number of cells. ...
8
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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 ...
5
votes
1answer
401 views

What produces the strong odor of decaying dead animals?

Are there specific chemicals responsible for producing the strong, putrid odor that is present after an animal deceases? Also, how long does this odor last?
10
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3answers
350 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 ...
7
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2answers
246 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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5answers
1k views

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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4answers
3k views

Why are there no wheeled animals?

In physics, "almost everything is already discovered, and all that remains is to fill a few unimportant holes." (See Jolly.) Therefore, on Physics SE, people are veering off into different directions: ...
4
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1answer
140 views

How do animals handle light refraction in different media?

For a human, when diving underwater, everything is blurry because of the water's different refractive index compared to that of air, which we are accustomed to. How do animals, like turtles, seals or ...
12
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1answer
130 views

Help identifying what this is in Crayfish gills?

this is my first time posting here. I was in my Zoology lab doing a dissection on a Crayfish when I noticed these hairlike structures within the gills. They were very "snappy" and fine, and would ...
3
votes
1answer
29 views

Why are killer whales found in the Gulf of Mexico smaller than ones found in the Pacific?

I recently found out that there are killer whales that live in the Gulf of Mexico, but they are smaller than killer whales that are commonly found in the Pacific Ocean. Why is it they are smaller in ...
2
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1answer
26 views

Cysticercoids of Eucestoda

I have found the following pictures representing cysticercoids of Eucestoda. If I correctly understand the right part of the picture, I would say that the development of the scolex is portrayed on ...
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2answers
79 views

Horns in animals and birds [closed]

Are there any carnivores with horns (whether extinct or currently alive)? Do any flying creatures have horns? By horns I mean horn like structure.
14
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2answers
1k views

How do birds deal with their eyes drying out at high speeds?

My eyes tear up when cycling at 15 mph, which is nothing compared to bird airspeeds. Do birds continuously produce lots of tears and blink a lot, or do the eyes self-moisturize from the inside ...
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0answers
62 views

How did birds become so intelligent?

I have seen a Discovery Channel video of a bird throwing stones in a pot to raise the water level so it is able to reach and drink it. A similar experiment in this paper from Current Biology shows ...
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0answers
24 views

Founders of Cnidarian colony

I know that colonial Cnidaria enlarge their colony by the means of asexual reproduction and sexual and asexual reproduction can originate individuals that will be part of other colonies. ...
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2answers
694 views

Do plant-animal cross races exist?

Plants and animals have the following distinct properties: Plants live from solar energy by photosynthesis, they use solar energy to make sugar and oxygen out of carbon dioxide, which gives them ...
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1answer
82 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.
9
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1answer
123 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. ...
18
votes
3answers
7k views

Do cows produce milk excessively?

Do cows produce more milk than it is required for their calves? It seems like cows are able to provide milk all the time (all year around). Is it so? Or do they, like other mammals, produce milk only ...
5
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1answer
59 views

(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 ...
0
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1answer
57 views

Why do insects avoid being on their back?

I have noticed that when insects are placed on their backs, they tend to turn themselves over quickly or else appear to be in distress. Is there a physiologic, anatomic, or adaptive reason why supine ...
4
votes
1answer
81 views

Why does cucumber skin kill ants?

I recently read that cucumber skin is an effective repellent for some ants: Set out cucumber peels or slices in the kitchen or at the ants' point of entry. Many ants have a natural aversion to ...
7
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2answers
78 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?
2
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1answer
39 views

Detailed mechanism of the cause of diabetes mellitus type 1?

I have read in some texts that diabetes mellitus type 1 is caused by degeneration of beta cells due to our body's own immune reaction.Is it true? Can you explain further how are such types of immune ...
15
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3answers
753 views

Are there cats with black skin?

Some mammals can have a black, pink or spotted skin, depending on race - see for example humans or pigs. But I recently learned that this is not the case with mice. Even black furred mice have pink ...
3
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2answers
163 views

Are these cats calico?

Calico cats are cats that have 3 fur colors and are always female or males two X chromosomes. I've seen many cats that will have 2 fur colors (one of them is usually white) and another, third, color ...
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1answer
22k views

Why are (some) cats attracted by bleach?

(Sorry if this question is only partly biological) I have noticed that several cats (including the one that keeps sleeping in my house), are fond of the odor of bleach (eau de Javel) and chlorine. ...
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1answer
5k views

Fish “coming back to life” after being frozen

I've encountered a clip on Youtube showing a goldfish thrown in liquid nitrogen and immediately after to normal water and swimming normally. In the explanation to the clip it says: For everyone ...
2
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2answers
259 views

How can we know or measure pain in animals?

Is there any standard way to know how much pain an animal feels when it gets hurt like when a bird loses it's wing or hen when killed etc. All pain sensation points? Hey I'm new to biology. :)
4
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2answers
95 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?