For humans, bulking up takes months at the gym. For some animals, it takes a couple of seconds.
I took the author’s prerogative at Saturday’s Weird Animal Question of the Week to ask “How and why do some animals inflate themselves?”
Some critters puff up to impress the ladies, like the male kori bustard.
The heaviest of all flying birds, kori bustards gulp air to inflate their throats and make their “percussive, booming call—probably useful for communicating across long distances in its typical flat, open habitat in Africa,” Marc Devokaitis, of the Cornell Lab of Ornithology, says via email. (Also see "Unlike Footballs, These Animals Are Meant to Deflate.")
The resulting look of this inflated esophagus, though, shares an uncanny resemblance with Santa's beard.
Male hooded seals, native to the Arctic and North Atlantic Oceans, have two inflatables: A flap of skin they inflate with their nostrils, which covers their head; and a pinkish red balloon blown through one nostril, which attracts females and warns off other males.
Male Arabian camels sport a dulaa, a part of the soft palate that the animals inflate during mating season to call to and impress females. The males most likely inflate the dulaa by diverting air from their respiratory passages, according to a 2006 study in the Journal of the British Veterinary Association.
Get Off My Back
Not all this self-aggrandizement is a form of attraction—female cane toads, for instance, go to great lengths to avoid romance.
According to a 2010 study in Biology Letters, male cane toads have a tougher time grasping a female who inflates her body. (See "Wild Romance: Weird Animal Courtship and Mating Rituals.")
This gives the female toad more leeway in choosing her mate.
Bigger is Badder—and Safer
The name pufferfish suggests these marine cuties are full of air.
But pufferfish inflate by swallowing water, says Adam Summers of the University of Washington via email.
“The stomach itself, and the pufferfish’s skin, pleats like a skirt,” Summers says, and as it fills, the pleats unfold “and it just gets bigger and bigger.”
Ballooning to an inedible size is great protection against predators—and if that wasn't enough, most individual pufferfish contain enough toxins to kill 30 people.
Another animal that uses the inflation defense is the puff adder, a common name applied to several different species of snakes—ranging from the harmless North American hognose to the venomous African puff adder, says Kate Jackson of Whitman College in Washington State.
When threatened, puff adders hiss and puff up their bodies to make themselves look larger. They do this by using their lung—singular.
Because of snakes' long and thin body shape, most species only have a left lung, which, in the case of the puff adder, can extend to fill much of its body cavity, Jackson says.
The siamang, the largest of the gibbon species, has a throat sac that can expand to the size of its head.
The Southeast Asian animals use the sac to make two loud territorial calls, one made with the mouth closed and the other with the mouth open. (Learn more about funky and incredibly agile gibbons.)
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