A rare video shows the mating ritual of hooded seals in the Arctic Ocean.
These seals can inflate a nasal cavity to the size of a balloon to attract females and scare rivals.
The scene is from the BBC series "Frozen Planet II" narrated by David Attenborough.
A rare video shows hooded seals competing over a female by inflating cavities in their nose to the size of a balloon.
It shows a mating ritual taking place in the frozen waters of the Arctic Ocean.
The video, below, was released alongside the BBC documentary series "Frozen Planet II," narrated by David Attenborough.
In the video, a young male hooded seal appears bobbing along a slab of ice, where a female is nursing a pup. A larger male is nearby who seems to have claimed the females.
The younger male jumps on the ice to intimidate the older male. He inflates his nasal cavity, which blows up like a black balloon on his forehead. The older male does the same. The display is accompanied by clicking sounds that echo in the inflated sac.
The older male eventually slinks back into the water.
Encouraged, the younger male heads towards the female and inflates once again. But this time, it comes out of his left nostril, appearing like a bright red balloon, as illustrated below.
The female is unimpressed and sends the younger male on his way with a bite on the tail.
"With only one day in the year in which to mate, the female is understandably choosy," Attenborough said in the documentary.
"And until the youngster has grown a more impressive balloon, he's unlikely to be chosen. No wonder he's deflated."
More than 600,000 hooded seals live across the North Atlantic and Arctic Ocean, per the National Oceanic and Atmospheric Administration (NOAA) fisheries.
The stretchy cavity in their nose is also called the hood, which gives the seals their name.
Males can inflate the cavity across their forehead when they reach adulthood. But it is only with sexual maturity that they are able to inflate the cavity as a reddish balloon under the nose. They shake these sacs violently to intimidate rivals and to attract females.
These massive animals, which can weigh up to 776 pounds and measure up to 8.5 feet, are mostly solitary. During most of the year, they are fiercely territorial and will fend off competitors more aggressively than other seals, per NOAA.
They only come together when they migrate to their breeding grounds east of Greenland over two or three weeks in the spring.
Because of their aggression, it is very difficult to get good footage of the animals, wildlife photographer Sylvain Cordier previously told MailOnline.
That's not the only bizarre fact about these seals. The females' milk is the fattiest in the world, Insider previously reported.
It contains about 60% fat. By comparison, gourmet ice cream is only about 16% fat, per Insider's Uma Sharma and Shira Polan.
The fatty food allows the pups to double in weight in their first week of life. Hooded seal pups are weaned off the milk in just four days, the shortest time for any mammal.