Hi, I'm Jess Keating, and you are watching Animalogic: Second Nature. [♪♪♪]
Hi there. What you doing way back there?
Come on up here. [Chuckling]
Ah, that's better. I'm glad you dropped by.
I've got a little story I think you'll like.
[Jess] A species' survival is entirely dependent
on its ability to exploit and compete for the resources
in their ecosystem. But sometimes
those ecosystems change and animals that have excelled
with one strategy for thousands of years
all of a sudden need to adapt. This can mean specializing
in a new niche, broadening their niche
to a more general diet, or pushing into an
entirely different territory. Over time this can lead to
the creation of a new species. Amphibious mammals.
Currently, several species of terrestrial mammals
are dealing with ecosystem changes
that have them turning to a life in the water.
[male announcer] Take this mother hippopotamus and her young son, Sabastian,
who's just learning to swim and is sticking close to mom.
[Jess] Here in Canada on Vancouver Island
live the sea wolves. These wolves are a population
of grey wolf that are beginning to draw
a genetic line in the sand, or beach.
Unlike interior wolves who primarily eat elk and deer,
these coastal wolves eat seafood.
Their diet is made primarily of salmon,
but they also eat clams, seals, otters, and marine carrion.
They travel great distances in search of food,
either by land or sea, and have been recorded swimming
12 kilometres in a single go. than interior grey wolves
and D.N.A. testing has found that they are actually
genetically distinct from their mainland cousins.
When hunting salmon, they hunt much like
grizzly bears.@They stand in the shallows where the salmon are spawning
and catch them as they jump out of the water.
These wolves were driven to the coasts and islands
as their original territory was logged,
leaving much less room for prey and predators to survive.
Yet, while life on the coast isn't what grey wolves have
excelled at historically,@they have found some advantages.
Hunting sm all prey like salmon
is a lot safer than hunting their traditional
diet of large ungulates which can injure a wolf
during the hunt. If interior wolves
wanted to hunt salmon, they'd be competing
with grizzly bears who take to the islands in much
smaller numbers, if at all. [male announcer]
Then one of the great epic struggles of nature begins.
Day after day, week after week. [Jess] Grizzly bears
are amphibious mammals, but they don't swim
all that often. They primarily hang out in the
shallows waiting for salmon. Polar bears, on the other hand,
are much more aquatic. Their habitat is made up of ice,
and as that ice melts, they must take to the seas
far more often. They have huge paws designed for
pushing their aerodynamic bodies through the water.
They spend the majority of the time in the water travelling,
preferring to ambush seals at seal holes
rather than diving for them. Though they will use the water
as a means to approach unsuspecting
prey stealthily. But they're not alone.
Jaguars, too, use the water to silently approach their preybefore striking.
Living in such vast diverse and changing ecosystems,
jaguars have become much more generalist in their diet
than other big cats. They're fantastic swimmers
and will dive into the water to hunt turtles, fish,
capybaras, and caiman. [♪♪♪]
[♪♪♪] [Jess] In the Sundarbans
in the mangrov e forests,
tigers often take to the water to cross from island to island
in search of prey. While tigers are
less amphibious than jaguars,
if their prey tries to escape them in the water,
they will dive in pursuit. [♪♪♪]
Though in the East,
the cat that reigns supreme among amphibious mammals
is the aptly named fishing cat. These rare felines are found
in the Bay of Bengal with most of them
living in the mangrove forest and swamps of the Sundarbans.
These cats are right at home in the water.
They're excellent swimmers and hunt their aquatic prey
either by fishing it out fromúthe surface with their big paws
or by diving in to get it. These bulky-looking cats m
ightúnot look like amazing swimmers, but they have a few adaptations
that give them an edge. @Their paws are partially webbed.
This helps propel them through the water
as well as giving them more surface area to walk on
when strolling through the muddy wetlands,
stopping them from sinking in. They also have thick layers
of fur perfectly adapted
for life in the water. The bottom layer
is short and dense. This keeps the fishing cat's
skin dry and warm while swimming.
The top layer is longer and this is where they get their pattern.
This is used for camouflage. [male announcer]
It looks like revenge, but the cat will be all right.
A little wiser and cleaner. Fishing cats took to the water
for survival. There was far too much
competition on land from similar predators,
but now they face the opposite problem.
As humans are pushing further and further
into their territory, the wetlands are beginning
to disappear @and the fishing cat will be left
to either adapt or die. While the king fisher
might hold the title for the most graceful diver,
perhaps the cutest diver is the most ridiculously
adorable water shrew. These shrews are the smallest
warm-blooded diving species in the world.
They're about the size of your thumb.
They're primarily insectivorous and have found a lot of success
hunting larvae in the water. They can dive
for up to 45 seconds. Not the longest dive
in the world, but it's long enough for
them to catch their prey. When they dive,
their fur fills up with bubbles, and when they stop swimming,
the bubbles push the shrew straight up to the surface,like an adorable
little lifejacket. These bubbles also give the
shrews a layer of insulation, reducing heat loss
This is especially helpful for the North American species
which dive in cold water for most of the year,
though the North American species have another adaptation
for staying warm during their cold dives.
They can control their metabolic demands,
creating more body heat on command.
There are even some reports of water shrews
that are able to walk on water. [Eric] He's over there.
[man] You gotta get this, Eric. This is like
pretty significant, man. [Jes
s] Their feet are covered in little fringes of hair that
may help trap air bubbles like their fur,
allowing them to not break surface tension.
This could be helpful when escaping predators
or possibly when hunting prey as it emerges from the water.
Unlike all the other animals we've talked about
who've changed their behaviour to take advantage of a new
or different ecological niche, the swimming pigs of the Bahamas
started swimming after the discovery
of an entirely different niche. Tourists.
The pigs Big Major Cay have discovered that
if they're really cute, humans will feed them.
And as it turns out, swimming pigs are in fact
pretty damn cute. We're not entirely certain
how the pigs got to the island in the first place.
They may have been brought their by people hoping to settle. They may have swam to
shore after a boat capsize, or they may have been
brought as tourist traps. Whatever the reason,
they're certainly making the best of it.
There isn't a lot of food for them to eat in the island,
so their diet relies on entirely what people bring them,
hence the cuteness. But this isn't a habitat
that they chose to push into. Instead they're making
do in a habitat where they're not meant to be.
Recently, ten pigs were found dead on the island.This was in part due to
people giving them alcohol. But autopsies revealed
that is was primarily from ingesting large quantities
of sand. Tourists would throw
their food on the beach which the pigs
would then swallow whole, sand and all.
This small island leaves them little room to adapt.
A couple of dry months can easily decimate
their populations, forcing them to eat and drink things that they shouldn't.
This is not the first time that mammals
have sought new niches in the water.
The ancestors of whales and dolphins
turned to the sea for food and slowly transitioned
from terrestrial to amphibian to fully aquatic.
Will these more recent changes in behaviour
lead to a more permanent split? With the world changing
as rapidly as it is, it's anyone's guess.
So what should we talk about next?
Please let us know in the comments,
and be sure to subscribe for new episodes of
Animalogic: Second Nature every other week.
Thank you so much for watching. [♪♪♪]
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