Questions tagged [mammals]

Questions related to mammals, animals that nurse their young, have a neocortex, and three middle ear bones.

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42k views

Cats, Dogs and Bears - how are they related?

What is the ancestral relationship between cats, dogs and bears? I presume they are more closely related to one another than other paraphyletic clades of mammal. Which came first? What did their ...
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1answer
220 views

Gestation period of African savanna elephants?

I found out it is 22 months for African bush elephants, but is this also true for African savanna elephants?
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141 views

Why do sea mammals die on land, and drown on sea?

It's quite confusing to me, why do sea mammals die on land, but also die from drowning if they couldn't reach the sea surface to breath? Excuse my ignorance but I am really confused!
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157 views

How to determine externally that a whale is a mammal?

Mammals have external qualifying characteristics like body hair, ear pinna, etc. But a whale has none of that. So, can it be identified as a mammal just by external observations?
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Why only female mammals have well developed mammary glands?

In course of evolution (possibly), mammary glands became vestigial in male mammals, but became fully developed in females. Is there any plausible explanation for this characteristic?
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267 views

Are bears related to dogs in a similar way to how cats are related to 'panthers'?

I've tried searching on Wikipedia but I couldn't find what family dogs belonged to. Ursidae is 'bears' and Canis is 'dogs' ; Panthera is big cats like:- tigers and jaguars is what I know.
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120 views

Whales and cancer [duplicate]

Do whales get less cancer than they should considering they have a lot more cells and tissue? If a lot of cancer formation is random because of mutations then shouldn't whales receive a lot of ...
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1answer
5k views

Why does the kidney of a cow have lobules, why the kidney of a human hasn't any?

The kidney of a cow has lobules, while the kidney of a human hasn't any. I can't think of any reason why it would be good for a kidney to have lobules. It would be good if the kidney needed to have a ...
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1answer
139 views

Heteromaternal Superfecundation - Any known cases?

Superfecundation in mammals (fertilization of two or more ova from the same cycle by sperm from separate acts of sexual intercourse) -- Is possible in nature from different fathers (Heteropaternal) as ...
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1answer
717 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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28 views

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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43 views

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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What do chimpz/bonobos/orangutangs/gorillas feed their babies with?

I just read this question and it made me curious about what a more original baby diet would look like. So, at what age do our closest relatives in the animal kingdom start giving their offspring more ...
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87 views

What is the closest relative to odd-toed ungulate?

I have seen about 3 variation of phylogenetic tree about odd-toed ungulate and I don't know which one is really updated or outdated or which one have more backed up theory First is odd-toed ungulate ...
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30 views

Do marsupials ever die in childbirth?

Question: Do marsupials ever die in childbirth? Obviously the notion of there being a linear ordering of "least advanced" to "most advanced" life forms isn't correct. Still, often marsupials are ...
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62 views

Are insects really strong or just small?

It's a common statement that insects are stronger, faster and jump higher than almost anything by mass. However, this leaves out that compared to their mass, all large creatures are actually pretty ...
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55 views

Why did the armadillo cross the border?

Armadillos evolved in South America. When the continent was joined with North America, one species - the nine-banded armadillo - spread north into Middle America. Apparently, the armadillo reached ...
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63 views

Basic behaviour patterns of animals for a modeling project?

I am working on a project (a tool) for my GIS class that models natural habitat of an animal based on landcovers, distance to the nearest watersource and distance from developed area in Kansas, USA. I ...
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423 views

Why were dinosaur skeletons so light compared to mammal skeletons?

I was watching a presentation by Dr. Jessica Theodor [1] who discusses (at 38:10), among other things, the skeletal structure of dinosaurs vs. mammals. "Dinosaurs have way lighter skeletons, which ...
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263 views

What is a common body composition in mammals?

The Physiology Of The Racing Greyhound states that most species have about a 40% muscle mass to body mass ratio. Understanding Body Composition puts "optimal fitness" in humans at 16-25% body fat for ...
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14 views

Does level of bats activity differs from day to day?

Say we measure bats activity as number of passes through given area. Can it differ significantly depending from day to day or it stays on average roughly the same? I am wondering whether the following ...
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33 views

Why there are two rounds of cytosine de-methylation in mammalian development?

I assume that the key biological meaning of cytosine de-methylation during germline development in germline progenitor cells is to reset imprinted genes and then set methylation pattern on these genes ...
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65 views

How do I get recombinant proteins into the nucleus of mammal cells?

I know that there are Nuclear Localisation Sequencenes (NLS). They can be taken from endogenous or viral proteins and fused to the N or C terminus of my recombinant protein. Which is the best one? ...
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37 views

Which agricultural crops attract rodents?

Are there any data on rodent populations per acre of different types of agricultural crops?
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6k views

Can Squirrels Eat Every Mushroom? [closed]

Squirrels have the ability to eat toxic mushrooms as described below. Are there any mushrooms that they can't eat without dying? According to Dr. John Rippon, an IMA member and world expert on ...
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173 views

Are there any mammals in which polyspermy produces viable zygotes?

Are there any mammals in which polyspermy produces viable zygotes? In the wikipedia page it is mentioned that there is a delicate equilibrium between female defenses against many sperms, which ...
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244 views

Red fox with blue legs

On the Wikipedia I found this photo of a red fox, labeled as being taken at Quesnel Lake, British Columbia: Why would the fox have blue legs? Is that normal for a Red Fox?
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123 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 ...
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86 views

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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1answer
123 views

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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2answers
136 views

Why aren't mammals and reptiles considered amphibians?

We've all heard it: birds descend from dinosaurs, so they're dinosaurs too. But this got me thinking: doesn't this mean that, for instance, all terrestrial vertebrates – including humans – are ...
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139 views

Why are monotremes so rare?

There are currently only five species of monotremes remaining, and all of them are found in Australia. Additionally, I read a science article claiming that competition from marsupials essentially ...
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1answer
56 views

Are there known life expectancy differences in non human mammals by sex?

In humans either for biological or cultural reasons there are life expectancy differences by sex. But how about non human mammals? Are there known life expectancy differences in non human mammals by ...
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2answers
521 views

Does Science Say That We Should Die? [duplicate]

Excluding situations where you die from accidents, the main reason for death is -generaly- diseases. And usually it is about an organ which becomes "tired" after many years. These results are all ...
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1answer
97 views

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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1answer
65 views

What are the migratory patterns of Orcas in the Pacific Northwest? Do they pass by Vancouver in the Fall?

What are the migratory patterns of Orcas in the Pacific Northwest? Do the pass by Vancouver in the Fall? I know you can never predict the sightings of a wild creature, but I was wondering what the ...
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1answer
156 views

Why do some animals have beards?

Why do some animals such as some Goats, Ibex, Orangutan etc, have long well-shaped beard like men?
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1answer
136 views

Do squirrels and blue jays play a role in oak tree distribution?

White oak (Quercas alba) acorns have lower tannin levels than red oak (Quercas rubra) acorns, therefore animals tend to eat the white oak acorns before red oak acorns. Animals such as squirrels and ...
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1answer
36 views

Do Pthirus gorillae remain in gorilla leaf nests after gorillas migrate and abandon them?

Gorillas build leaf nests to sleep in. Do the lice which parasitise gorillas, Pthirus gorilla, remain in gorilla leaf nests after gorillas migrate to new regions (and abandon the old nests)?
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1answer
41 views

Which variables are controlled in the mammalian womb to ensure a healthy environment?

Recently, researchers have had some success with artificial wombs. Which aspects of the womb are difficult to replicate through technology?
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1answer
44 views

Book recommendation on mammal (or just primate) behaviour, especially in relation to child-rearing

I have a growing frustration with the lows 'new-age' parenting is reaching, along with asininity of so much of our public schools' (and summer camps') philosophies and policies in relation to our kids....
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1answer
1k views

Are females more flexible than males in all mammals?

It's common that human females have a more flexible body than males, (but I don't know why, so it'd be helpful if someone answers why so as well!) but does this apply to all mammals?
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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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29 views

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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125 views

Which mammal produces the most milk?

I'm searching for mammal who can produce most milk whenever she lactate. I Googled it but it says dairy cattle which biologically speaking is not right answer, because a baby whale can drink up to 150 ...
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72 views

Are humans the only primates being engaged in group sex?

There are quite many examples of humans being involved in group sex. I won't say it is a common thing and won't say whether it is "natural" or "cultural" (but "cultural" only means induced to majority ...
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95 views

How “unique” human vagina is?

Regading penis Dixson showed that it is not really unique and complex. This argument (and there were some others) was used against the idea of human polygynandry. But what about vaginal shape? I know ...
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Is there any data to explore the heterozygosity of the South African lion over the last 18 years?

Background: I need to find data on the heterozygosity of the south African lion over the last 18 years... and I'm struggling: so far I have found a single data point. Question: Where can I find ...
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37 views

Are there mainstream views on the mandrill's coloration's being so unique?

According to the Wikipedia article: Mandrills are noted as being exceptionally colourful for mammalian standards. Charles Darwin wrote in The Descent of Man that "no other member in the whole ...
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Tests for object size discrimination in mammals?

Are there common testing protocols for establishing whether an animal (mammals especially) can distinguish the size of objects? In particular, are there procedures or is there good literature on ways ...