A year in the life of one of Earth's weirdest animals - Gilad Bino

1,158,375 views

2021-07-27 ・ TED-Ed


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A year in the life of one of Earth's weirdest animals - Gilad Bino

1,158,375 views ・ 2021-07-27

TED-Ed


Please double-click on the English subtitles below to play the video.

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Waddling along the parched Australian earth,
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this female platypus is searching for fresh water.
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Over the past year, a severe drought turned rivers and streams
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to mere trickles.
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She barely survived and was unable to reproduce.
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Could the next year bring a change in luck?
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It's autumn and fat raindrops finally come spilling from the sky.
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Within days, the platypus finds a river and begins to hunt.
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Her webbed feet propel her along
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and her waterproof coat traps heat close to her body.
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Underwater, she senses her surroundings with her duck-like bill,
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which is fitted with about 40,000 electroreceptors.
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This allows her to detect the minuscule electrical signals
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coming from a glass shrimp’s nerves and muscles.
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She makes it a quick meal.
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And once she clambers back on land to construct a burrow,
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she waddles in a lizard-like posture,
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her limbs moving horizontally to her spine.
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The platypus has many quirks.
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As a monotreme, she's part of the most ancient lineage of mammals alive today.
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Consequently, she has a curious mix of mammalian, avian, and reptilian features,
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which is reflected in her genome.
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For instance, mammals usually have one pair of chromosomes that determine sex.
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But the platypus has five, which more closely resemble a bird’s.
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Let's hope she gets to put them to use.
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She regains her strength and, as winter turns to spring,
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it’s time to mate.
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However, she can’t raise her young here.
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The surrounding land has begun to be deforested,
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causing the riverbank to erode.
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Instead, she journeys upstream
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and settles in a clear, deep pool sheltered by a river red gum tree.
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Suddenly, a rustle flushes birds from the undergrowth and a fox appears.
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These predators have threatened platypuses
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ever since they were introduced to Australia by white settlers in 1855.
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The fox doesn’t see her this time, but the platypus will need to stay alert.
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Two males also occupy this area and, soon enough,
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they begin competing for her affections.
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Each has spurs on its hind legs containing a potent snake-like venom.
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One male fights the other off and courts the female over several weeks,
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swimming alongside her, and occasionally biting her tail.
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Eventually, she reciprocates,
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and they swim around in circles before doing the deed.
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The male platypus has a penis with eccentric features
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like two heads and spines that aid and fertilization.
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Over the following week, the female constructs an extensive burrow
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furnished with a cozy nest.
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She plugs up the tunnels leading in,
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making them appear as dead ends to potential predators.
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Then, much like a reptile or bird, she lays eggs from her cloaca,
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a single opening that's used for both reproduction and excretion.
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She incubates her eggs, and as the river red gum tree blooms,
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her offspring hatch.
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Like other mammals, she feeds them milk.
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But unlike other mammals, she has no nipples.
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Instead, her milk oozes from mammary glands onto her belly,
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where her babies slurp it up.
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This pooled milk invites bacteria,
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but the platypus also produces potent antibacterial proteins,
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ensuring her newborns are safe.
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She continues nursing them for four months—
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hunting, evading the fox, and repairing her burrow all the while.
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By the time her young are ready to make their debut,
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the summer is waning.
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One evening, after the female platypus returns from hunting,
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she finds that one nestling has already struck off on its own.
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A few days later, the other also leaves the borough.
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Soon, her young are living completely independently.
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And eventually they’ll leave this part of the river to make homes of their own.
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