Look around you sometime…
Chances are – if you see an animal – it’s a mammal. Mammals
are the dominant life form on this planet at the moment, at least from a human
perspective.
There are about 6,399 species of mammals known on this
planet at the moment. Though taxonomists are still arguing and species are
still being found.
Mammals are in fact not the most speciose animal group on
the planet.
Three other groups of vertebrates out-number them right now:
Reptiles have 11,050 species,
Birds have 10,988 species and
Fishes approximately 34,300 species.
Invertebrates – of course – have groups with huge numbers of
species that outnumber all the vertebrates put together: Arachnids, with a
100,000 species and insects with 1,000,000. While even Molluscs with a mere
85,000, still outnumber any 3 groups of vertebrates put together.
Mammals however are big. You can see them easily – and
perhaps most importantly you are one.
Mammals are there, everywhere you look. Large, warm-blooded,
four-limbed vertebrates whose females produce milk
Elephants and Whales, Pigs, Horses, Cattle, Sheep, Dogs, Cats,
Hamsters, Rats and of course Human beings (that’s you and me) are all mammals.
Mammals are friendly or fierce, cuddly, cute and/or awesome
– depending on which ones you look at.
They fascinate and horrify us at the same time!
We eat them, ride them, keep them as pets, makes clothes out
of them, hunt other mammals with them and use them as substitutes for ourselves
in scientific (particularly medical) research.
We use them to carry our burdens, support our foolish habits
(gambling) and expect them to entertain us. To most people animals are mammals.
Many people are totally dependent on non-human mammals to
keep their lives functioning (vegetarians and vegans excepted) and many of us
need them as emotional supports as well.
We are mammals (genetically a man and his dog are 97% the
same) and we love them because they are like us.
We use them to describe people. Someone is a dog, bitch,
stallion, pig, cow, kitten, bunny… we run like a rabbit, weasel out of a deal,
are as sly as a fox, as strong as an Ox and can have a whale of a time!
Our mammalian cousins are very important to us.
But how much do you really know about what it takes to be a
mammal?
Mammals may have only become successful as a group
relatively recently, but they have been around a long time.
The first mammals appeared about 265 million years ago, a
mere 10 million years after the first dinosaurs. But they remained relatively
obscure for the first 160 million years while the dinosaurs ruled (see The
Evolution of Mammals).
Anyhow, let’s continue our journey of learning, starting
with some of the most interesting facts about mammals:
The Largest Mammal In The World
The Blue Whale, Balaenoptera musculus, is the largest mammal
living today.
It is also the largest mammal to have ever lived. In fact
the Blue whale is the largest animal ever to have lived on the planet, as far
as we know. Bigger by far than even the largest Dinosaur.
The longest Blue Whale ever measured was a female, 33.58m or
110ft long. The heaviest weighed over 190 tonnes.
blue whale facts
The largest animal in the world, a blue whale showing its
back
Well, we haven’t actually got a set of weighing scales big
enough – so weights are estimated from the cut up remains.
The largest living land animal on this planet is a mammal –
the bull African Elephant. The largest specimen recorded stood around 3.96m or
13ft at the shoulder and weighed over 12 tonnes.
The tallest animal on the planet is also a mammal –
Giraffes, Giraffa camelopardalis, can be 6.1m or 20ft tall.
The Smallest Mammal In The World
The smallest mammal in the world is a bat from Thailand,
Kitli’s Hog-nosed Bat, Craseonycteris thonglongyai.
Being only 2.9-3.3cm or 1.14-1.3 inches long and weighing a
mere 1.7 – 2 g or 0.06 – 0.07oz, this bat is much smaller than many insects and
snails.
smallest mammal shrew
Pygmy shrew (Suncus etruscus)
In a close 2nd place, the Pygmy or Savi’s White-toothed
Shrew Suncus etruscus weighs in at 1.5 – 2.5 grams or 0.05 – 0.09oz and is
definitely the smallest land mammal on record.
The Fastest Mammal
The Cheetah, Acinonyx jubatus, is the fastest animal on land
– reaching sprinting speeds of over 98 kmh or 61 mph. In 2012 National
Geographic radar recorded an eleven year old Cheetah named Sarah running at 98
kmh. Sarah was a zoo kept animal who
didn’t have to run flat out every day to catch her dinner and eleven years is
getting old for a Cheetah, therefore scientists believe younger animals living
wild can probably run quite a bit faster than this, perhaps up to 110
kilometers per hour.
fastest mammal cheetah running
Cheetah (Acinonyx jubatus) running through savannah at fast
speed
The fastest mammal in the water is the Killer Whale, Orcinus
orca, which has been recorded swimming at speeds of 55.5 kmh or 34 mph!
The fasted mammal in the air is the Big Brown Bat, Eptesicus
fuscus, with a recorded flight speed of 25 kmh or 15.5 mph.
Which Lives Longest?
The longest lived mammals are not human beings – as many
people think – but the whales.
Fin Whale Balaenoptera physalis is believed to have a
maximum life-span of 90 – 114 years, a little less that the human maximum.
But Bowhead Whales (Balaena mysticetus), also known as
Greenland Right Whale has been known to live to at least 170 and possibly more
than 200 years since the mid 1990s.
A Few More Mammal Facts
Rhinoceroses have the thickest skin of any terrestrial
mammal… and the thickest skin in relation to their size, of any animal. The
skin on their backs and flanks can be 2.5 cm or 1 inch thick!
rhino thickest skin
Closeup on rhinoceros skin from the side
Nearly a quarter of all mammals can fly.
Yes, it’s true. With a huge 985 species, bats make up 23.1%
of all known mammals by species.
The meek shall inherit the earth, or at least Australia
(which is a reasonable portion of it). With about 67 million head of sheep,
there are about 3 sheep for every person in Australia!
A prehistoric mammal, the extinct Irish Elk, Megaloceros
giganteus, had the largest antlers ever. A specimen found in an Irish peat bog
had antlers 4.3 m or 14 ft across, which weighed 45kg or 100 lbs.
The Giant Anteater, Myrmecophaga tridactyla, eats over
10,000,000 ants or termites a year.
giant anteater fact
Closeup of Giant Anteater (Myrmecophaga tridactyla) walking
on grass
No two Giraffes have the same pattern of spots and no two
Zebras have the same pattern of stripes.
Whales and dolphins sleep one side of their brains at a
time. While one side is asleep the other keeps watch for danger!
Sperm Whales can stay submerged for up to two hours,
descending over a mile below the surface.
The Andes Fishing Mouse was first recorded for science when
scientists from the British Mammal Society watching a television programme on
the ‘Wildlife of the Andes’ saw a specimen in the programme and realized that
no records of it existed.
House mice, Mus musculus, have on several occasions been so
numerous that they had a population density of over 200,000 per hectare. That’s
2 mice for every square meter of land, if they were all spaced out evenly.
house mouse population density fact
Eastern House Mouse – Mus musculus
Rodents, at least the few species that are pests, cost us
about £43 million tonnes of damaged and destroyed food every year.
There is a vine in Madagascar that is pollinated exclusively
by lemurs.
Chimpanzees can go bald as they age.
A female kangaroo can produce 2 different kinds of milk at
the same time, when she is suckling youngsters of different ages.
fun fact about kangeroo
Female kangaroo with joey
Anteaters are the only placental mammals to have no teeth.
Hippopotamuses produce a special reddish oil from modified
sweat glands that acts like a sun-cream to stop them getting sunburned.
Shrews evolved 54 million years ago. Today some species have
such fast metabolisms that they need to eat up to 1.3 times their own weight in
food everyday.
A contender for the smelliest mammal is most definitely the
Striped Polecat or Ictonyx striatus. It releases a spray from its anal stink
glands that not only blinds any attacker, but leaves its skin in searing pain.
0 Comments