Questions tagged [mammals]
Questions related to mammals, animals that nurse their young, have a neocortex, and three middle ear bones.
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If density and anchorage prevents mammalian cells from forming multiple layers, how is it that tissue (like the dermal tissue) have multiple layers?
This figure from Campbell Biology shows how mammalian, normal (non-cancerous) cells form only a single layer before anchorage-dependence and density-dependence inhibit cell division, unlike cancer ...
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Why do dogs still have periods if they have an estrous cycle?
I recently learned that in most mammals, the endometrium is reabsorbed in the estrous cycle. Thus, I would expect dogs not to have periods (at least similar to periods that come from the menstrual ...
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Have lions, tigers, and cheetahs begun to lose or not yet fully gained tree climbing traits?
Leopards, jaguars, and the domestic cat all regularly climb trees, but lions and tigers rarely do. From what I can tell from a basic online search, the latter are inexpert tree climbers, but they ...
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Why are animal's whiskers in a square lattice?
I was observing my cat up close when I noticed his whiskers were in a square lattice as a novice mathematician, took notice of it and wanted to know if any other animal had this peculiar feature, so I ...
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What mammalian species has the greatest relative variance in adult size?
The smallest adult chihuahuas weigh about 2 kg, and the largest adult English Mastiffs are around 104 kg, making them 52 times larger by weight.
Of course, this enormous variance is the result of ...
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Are animal whiskers a useful monitoring tool?
I have come across studies that have used stable isotope values from seal/sea lion whiskers to infer foraging ecology. However, I am also aware that whiskers can fall off and then grow back. Is there ...
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Why is the sex ratio of male and female cats close to 50/50 (with males actually being more prevalent)?
According to this study from 1970, cats are about 50% male and 50% female. Furthermore, there appear to be about 100 male pedigree cats born for every 92 female cats.
I couldn't find any info about ...
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What happens to quality of breast milk when twins of two different sexes are born?
It says here in Scientific American
Mother's milk may be the first food, but it is not created equal. In
humans and other mammals, researchers have found that milk composition
changes depending on ...
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What are these animals, and what happened here?
While walking along the northern shore of Lake Ontario, I noticed the following strange scene:
Here is a closer angle:
What are these animals, and what is the likeliest cause of this?
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Is there any species of mammals where males can feed the offspring with milk?
It seems to me that an evolutionary path where not only females, but also males could feed the offsprings is entirely plausible: the males anyway have niples, so it is easy for the offsprings to ...
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Why do fish and marine mammals need special low density adaptations for buoyancy?
When one reads about fish and marine mammals, it is always said that for example blubber of marine mammals helps them with buoyancy because it is so low density and similarly for example sharks have ...
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To which ungulate species does this tooth remainder belong?
Found on the beach in Çanakkale, Turkey.
I have found a lot of these, but this is the first one that has parts like long teeth. My other findings have sometimes 4, sometimes 6 tubes. Very solid, ...
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What made this pile of tiny poops at the base of an old oak? Eastern Long Island, NY
I ran across three trees (all with cavities) that had mounds of these small droppings at their base. These were approximately 50-100 meters from the shore of a salt marsh on the east end of long ...
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If massive animals live longer, why do humans with gigantism die younger?
What I mean is humans suffering from gigantism (type 1 neurofibromatosis, Marfan syndrome, X-linked dominant acro-gigantism, et cetera) rarely live more than 5 decades (50 years).
The same can be said ...
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Do whales ever just hang out on the surface breathing?
You only ever hear of whales surfacing for a brief second to exhale/inhale before they dive back down. But do they ever just stay at surface level, laying there with their blow hole up in the air, ...
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Have scientists tried to communicate with Sperm whales?
I see lots of passive studies of sperm whale click "language", usually focused on fingerprinting to identify groups and individuals. There's application of deep learning, and all sorts of ...
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Did mammals evolve from something with eusociality?
Eusociality (from Greek εὖ eu "good" and social), the highest level of
organization of sociality, is defined by the following
characteristics: cooperative brood care (including care of ...
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Do beavers' tails hurt from being dragged?
I understand that when beavers walk on land, they drag their tails behind them on the ground. Their tails look quite large and rather heavy, and the ground is often rough - does dragging the tail not ...
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Bats observed hunting insect prey - any evidence of "handedness" (laterality) in circular flight pattern?
Whilst watching a bat hunting on the wing at dusk (most likely was a species common to my urban UK location, e.g. pipistrelle) its flight pattern around the garden comprised circles, several metres in ...
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Specific mechanism behind lethality of yellow coat color in mice
Our high school genetics chapter has some extra information about L.Cuenot. It only covered his research, and the fact that mice homozygous for yellow coat color would die before birth. It was an ...
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Mystery rodent in Winnipeg
I spotted this rodent in Winnipeg, Manitoba, Canada on September 6, 2020.
It is about 10 inches long.
What is it?
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What is the animal in Nosferatu movie? [closed]
I was watching Nosferatu, and this dog-like animal appeared, with very curious stripes. I was wondering if this is clearly a specific animal, and which one it is, or if it's too mixed up and low ...
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Why do mammals rarely have eyespots?
An eyespot is a marking to mimic the eyes. Many examples of eyespots can be found in fish, reptiles (including birds), and insects. Recently Radford 2020 has shown that artificial eyespots can reduce ...
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What is the primary cause of death for small animals in urban and suburban areas?
Small birds (sparrows, robins, jays, finches) and mammals (squirrels, rats, opossums, raccoons) are a common sight in many urban and suburban communities with green space. However, I observe carcasses ...
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How does a sheep's fleece impact its tolerance for high temperatures?
I am interested in whether a sheep endures more stress when its environment is hot if it has a full fleece or if it is recently shorn. Put another way, at the extremes, is a sheep more likely to die ...
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Has a primate species ever weighed the average mass of a tonne (1000 kg)?
I ask because primates are mammals from the euarchontoglires superorder. Most mammals that weigh a tonne are laurasiatherians (except for elephantids and their ancestors) (elephantids are afrotherians)...
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What coronaviruses have been identified in racoon dogs?
Christian Dorsten says in an (Apr 26) interview in the Guardian that racoon dogs as [intermediate] source of coronavirues have been overlooked (in China):
Q: What do we know about that intermediate ...
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In north America is their mammals that can survive from falling from hundreds of feet? [closed]
Like animals have great attributes but is their any mammals that have unique attributes to survive such fate of death?
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Why animals haven’t yet evolve in 2020? [closed]
In past when I was born like 1990s I notice most animals haven’t evolved in 30yrs. Example cats haven’t gain more muscular body as to be strong to defend themselves from predators like well many ...
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Did my wildlife camera take pictures of coyotes?
A wildlife camera took these photographs of these animals. These are the only pictures my camera collected of them. This picture was taken in the central interior of British Columbia, Canada. The ...
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Like Mother Cape Buffalo,do remaining mammal mother species also try to protect their babies from being eaten by predative animals?
Some statistics say that on earth there are approximately 5500 mammal species.I have seen a video of Mother Cape Buffalo protecting it's calf from being eaten by predative animals.Like Mother Cape ...
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Why do some mammals have incomplete orbits?
I've noticed that a lot of carnivorous/omnivorous mammals (most, if not all the members of carnivora and some ancestral cetaceans), as well as some herbivores (marsupials), have incomplete orbits that ...
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Why are Aardvarks capable of burrowing given their size?
I was wondering if large animals could possibly dig extensive burrows for themselves to live in. The polar bear burrows, but snow is not dirt. The aardvark goes about 4' long, ~150 lbs: similar to a ...
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Why are smaller mammals more prone to cancer and tumors
especially rats and mice usually develop cancer and tumors very fast, reducing their life expectancy.
From an evolutionary point of view, how come that these mammals are so prone to cancer and tumors ...
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Are there any animals that are unable to hear the human voice?
Humans and animals have different hearing ranges. The frequency range of a human, for example, is stated with 20 Hz to 20 kHz, whereas the fundamental voice frequency is stated with 125 Hz for men, ...
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Did any warm blooded animals evolve back into cold blooded?
Pretty much as title says - wondering if evolution can go from mammal back to reptile - either in theory or practice.
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Eagles carrying off a goat to its nest: How heavy is the young goat? How strong is the eagle? Here is my guess:
I posted a related question, here, trying to identify the exact subspecies of animals. In the documentary El Hombre y la Tierra, a golden eagle carries off some sort of juvenile(?) goat.
The Japanese ...
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What pigment is responsible for the formation of blue skin color in some animals?
Not long ago I read about Vervet monkey. Here's picture:
My question is what causes this blue coloration of the scrotum? I don't mean evolutionary need (e.g. attracting females), but what pigment or ...
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Why is there such a long interval between ages of sexual maturity and of reproduction in female chimpanzees?
There seems to be some disagreement on the ages at which female chimpanzees typically reach sexual maturity and when they typically first give birth, but regardless, different sources seem to agree ...
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Do animals like Seals feel cold on their skin?
Whenever there is a documentary about animals and you get to the colder regions, you will hear about Seals and their layer of blubber keeping them warm.
But the skin is on top of the blubber, in ...
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What kind of skull is this-I found it on the beach in Cape May
I am hoping someone can help identify this skull! We found it on the beach in Cape May. The skull size is about 4 inch in length. Thank you.
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Age until physical growth ceases, mammals
Fairly basic, but I am seeking a table showing how many years from birth it takes for the best-known mammals to stop growing. (Including the latest on humans - ie. 0-17..?).
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What are the differences between mammal and insect digestion of cellulose?
I know that digestion of cellulose is difficult in mammals and requires a lot of steps. But I am fascinated by the idea of one day achieving human digestion of cellulose.
Which got me thinking about ...
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Do male skunks have teats?
Simple question. Do male skunks (striped skunk, eastern US/Canada if it matters) have teats? Occasionally want to identify road-kill, but don't know if teats are diagnostic for females. I believe ...
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Mammal Statistics about Natural Death Versus Being Killed?
Is there data determining what percentage of mammals die a natural death (disease, old age) and what percentage die due to being killed and/or eaten by other mammals?
In watching wildlife ...
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What about this bat?
This happened in LaGrange GA. We heard some crawling around behind one of the faux-wood shutters on our front porch. So I eased it back and saw this:
If you can't make out the scale, the furry part ...
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Are there poisons that affect only mammals but not reptiles
Are there poisons that affect only mammals but not reptiles or crustaceans?
E.g. hemotoxins which affect hemoglobin but not hemocyanin or specific Na+ channels?
Looking for a "nice" poison/disease as ...
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How exactly does symbolic language for apes work?
I'm talking about the panels with lots of colored symbols on them you sometimes see in documentaries and the like. Apes point at the symbols in a specific order and in this way can communicate with ...
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Limbs in synapsids
Within synapsids, there was a change from a lizard-like sprawling posture (like in pelycosaurs) to a more erect stance. Non-eucynodont eutherapsids seem to have had a facultatively erect hindlimb and ...
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How are the first mammary glands thought to have functioned?
I happened upon a book (not about biology) containing this text:
A life-changing birth occurred on the planet about 190 million years ago [...] the first tiny shrew like creature brought forth an ...
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