Етесіздер тұқымдасы: Ортақ және дақты түлендер

Genus of carnivores

Phoca (/"//f//oU//k//@/ FOHkə) is a genus of the earless seals, within the family Phocidae. It now contains just two species, the common seal (or harbour seal) and the spotted seal (or largha seal). Several species formerly listed under this genus have been split into the genera Pusa, Pagophilus, and Histriophoca. Until recently, Phoca largha has been considered a subspecies of Phoca vitulina but now is considered its own species. For this reason, the fossil history of the genus is unclear, and it has formerly been used as wastebasket taxon for a number of fossils of uncertain affinity.

Both harbour and spotted seals are aquatically mating pinnipeds. Females in estrus are typically more dispersed than land breeding pinnipeds and the distinction between foraging and reproductive behavior is less apparent. For this reason, it is difficult to study the mating patterns of this genus. Female harbour seals start making foraging trips shortly before weaning their pup and consequently are widely dispersed when in estrus. Males restrict their range around the time females start to make these foraging trips. Harbour seals follow a polygynous mating system. More specifically it has been shown that male harbour seals partake in lek polygyny. Male seals defend underwater territories with well defined boundaries. The most valuable territories are near haulouts or along traffic corridors that provide maximum exposure to estrous females. Males assess each other by their vocalizations before deciding whether to respond. These vocalizations are energetically expensive to produce and are honest signals of male quality and dominance. Male body condition will decline as the mating season progresses. Aquatic courtship is long in duration and involves rolling, bubble blowing, and splashing to attract females. During the breeding season, a male will join a female approximately ten days before the female gives birth to a pup from the previous years mating. The pairs are considered to be territorial as they keep widely spaced from other spotted seals. The social group consists of an isolated adult pair and the females pup. The female spotted seal receives direct benefits from the male as he provides protection for her and the pup until it is weaned. Immediately after weaning mating occurs.