Hooded Seal

Hooded Seal Baby

Hooded Seal Male

These seals are solitary by nature, spending most of the time without the company of any other fellow seals. However, they spend time together with a member of the opposite sex only breeding and molting. These seals are more territorial than most other species of seals, and would even become aggressive when in defense mode.

During the time of molting in around July, they would get together near the Denmark Strait. The hooded seals fast when they molt and breed. Prior to the mating season, the couples gather at different sites close to the strait.

While very little has been learned by the scientists about these creatures, it is during these congregating periods that they have carefully been studied.

The male seals display their inflatable nasal sac (hood) especially when they seek for the attention of the female, but also when they feel threatened. Males with larger hoods have better chances to get a mate. While diving, the seals usually stay underwater for almost half an hour, however, they can stay even longer. While swimming, they can reach a speed of up to 27 km per hour.

The hooded seals are carnivorous and mostly feast upon fish like herring, cod, redfish, and capelin. Other than that, they would also hunt for mollusks like mussels, octopuses, squids, starfish, and shrimps.

Reproduction & Life Cycle

Lasting only for two to three weeks, the mating season of this phocid usually falls around the end of March. The female hooded seals would haul out on floes of ice to give birth to the pups. Pregnancy in hooded seals lasts for about 11 months and ends with a single baby. Interestingly, the baby seal takes birth in a developmental stage.

Very little could be known about the movements of juvenile seals during the first few years of birth. At the end of the concise lactation period, the parents return to the water, while the pup remains alone for several days, or even weeks, on the ice.

Although the suckling period is short, the mother’s milk has a very high fat content, while the babies can readily double their size. During the suckling period, the father hooded seal temporarily leaves the mother and the baby in search of other mates.

During this time, the babies thrive entirely on the fat reserves stored in their bodies. When they grow a few weeks old, they begin with their first foraying into the water, teaching itself diving, foraging, and swimming.

The age of sexual maturity in these seals is 4 years. The males start developing their ‘hoods’ by the age of 4 years, and it becomes fully developed by the time they are 12.

Hooded Seal Pup

The Hooded Seal

Adaptations

1. When the seals would spend time on land, they do show some shivering behavior; however, when these creatures dive even in the cold waters, they do not display any shivering mechanism since such an action would lead to an increased need for oxygen, eventually cutting the time short to stay underwater.
2. The seals have the ability to keep their nose closed while swimming to avoid water from accidentally entering through their nostrils.
3. These creatures use their whiskers to navigate through the waters, as also detect underwater predators.
4. The hood of the hooded seals has multiple functions. The seal can inflate its hood, which can be double the size of its head to startle and scare away the predators. While swimming, it is also used as a kind of noisemaker, i.e., when vibrated, the organ can emit a sound as a warning to the other seals away from the territory.
5. Their typical silver-grey to bluish grey body coloration helps them camouflage in the sheets of ice.

Predators

The primary predators of the hooded seals are killer whales or orcas, polar bears, and sharks.

Conservation Status

This phocid is a vulnerable species since their population is going down at a considerable rate. The IUCN 3.1 has categorized them under the ‘VU’ (Vulnerable) species list.

Hooded Seals

Hooded Seal Skull

Interesting Facts

• The weaning and lactation periods of these seals are the shortest known for any mammal, with the baby seals suckling only for four to five days.
• The average size of the hood in males is two times bigger than a football, with a volume of approximately 6.3 liters.
• The generic name Cystophora comes from Greek, which means the ‘bladder-bearer’.
• The baby hooded seals are known as ‘blue-backs’ since their coats are bluish-grey on the dorsal side and whitish on the ventral.
• A group of hooded seals is known as rockery, pod, harem, flock, herd, and colony.

• Video

• References

  • 1. https://www.britannica.com/animal/hooded-seal
    2. https://seaworld.org/en/animal-info/animal-bytes/mammals/hooded-seal
    3. https://www.oceansoffun.org/pinniped_species/21
    4. http://eol.org/pages/328632/details