Leopard seals are one of the most challenging top predators to examine due to the severe temperature in Antarctica, the species' solitary lifestyle, and its fatal reputation.
Marine biologists have now collected baseline data on the ecology and physiology of the leopard seal, the Antarctic's mysterious apex predator.
The apex predator of the Antarctic
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Sarah Kienle, Ph.D., a marine scientist at Baylor University, has long been captivated by leopard seals.
These ancient, reptilian-looking seals are frequently portrayed as terrifying antagonists in films like "Happy Feet" and "Eight Below," but little is known about their fundamental biology, as per ScienceDaily.
Leopard seals are one of the most challenging top predators to examine due to the severe temperature in Antarctica, the species' solitary lifestyle, and its fatal reputation.
Professor Daniel Costa, associate professor Stephen Trumble, Ph.D., professor Shane Kanatous, Ph.D., wildlife biologist Mike Goebel, Ph.D., and professor Daniel Crocker, Ph.D. embarked on a groundbreaking study funded by the National Science Foundation with a single goal in mind: to learn more about leopard seals.
The study of 22 leopard seals off the Western Antarctic Peninsula, which is quickly warming and changing, lasted two years.
They weighed and measured each seal and used satellite/GPS tags to track their activity and diving patterns.
Kienle (first author) and colleagues recorded the flexible behavior patterns and characteristics that may offer leopard seals the adaptability required to withstand the extreme climate and environmental disturbances occurring around Antarctica in their study published in Frontiers of Marine Science - Plasticity in the morphological features and movement patterns of an Antarctic apex predator, the leopard seal.
According to Kienle, "this study considerably expands our understanding of leopard seals' life cycle, spatial patterns, and diving behavior."
They show that these leopard seals exhibit a high level of diversity (or flexibility) in these many features.
Variety is essential for creatures adapting and responding to changes in their environment throughout the animal world, therefore we're pleased to observe such variability in this Antarctic predator.
Female leopard seals are significantly bigger than males; in fact, females are 1.5 times larger and longer.
The researchers measured one of the world's largest leopard seals, an adult female dubbed "Bigonia" who weighed 540 kg (1,190 lbs.).
Female-biased sexual dimorphism (where females are bigger) is rare among marine mammals, which include polar bears, whales, dolphins, seals, and sea lions, but leopard seals are the most severe example among the 130+ species of marine mammals.
In this investigation, two mature female leopard seals were pulled out on the e in the middle of the ocean for two weeks without eating or swimming.
Kienle and colleagues hypothesize that female leopard seals give birth and feed their pups during this two-week haul-out phase.
After two weeks, females return to the ocean and resume diving for food, while also weaning their pups.
Because the leopard seal is performing all of these extremely energetically demanding behaviors without food, they only have a little time to spend with their pups.
It is unknown why females are larger than males, but Kienle stated that previous research demonstrates that larger females are better at protecting eating locations and taking prey from smaller seals.
Larger females consume larger, more energy-dense food such as fur seals and penguins, whilst males and smaller females eat smaller prey such as krill and fish.
This shows that bigger body size in adult females is advantageous and provides a selective advantage, which Kienle and colleagues will continue to investigate.
The likeness between this seal and the sea leopard is more than skin deep. Leopard seals, like their feline namesakes, are vicious predators, as per National Geographic.
They are the most fearsome predators of all seals and the only ones that feed on warm-blooded food like other seals.
Leopard seals hunt smaller seals, fish, and squid with their formidable jaws and long fangs.
These deadly predators reside in the Antarctic and sub-Antarctic seas, where they prey on penguins.
They frequently wait underwater near an ice shelf and trap the birds when they jump from the ice into the sea. They may also appear beneath resting seabirds on the water's surface and snare them in their jaws.
Leopard seals have no ears. They have large heads and lengthy bodies (10 to 11.5 feet). Leopard seals, like most other seals, are protected from cold waters by a thick covering of fat known as blubber.
Though the leopard seal is noted for its coat, unlike its fur seal siblings, it has not been commercially killed for its skin.
