Cystophora cristata [Hooded Seal]
× Pagophilus groenlandicus (♂) [Harp Seal] NHR. CON: Gulf of St. Lawrence (North America). Harp seal males are about 1/3 the size of hooded seal males. Kovacs et al. 1997†.
Halichoerus grypus [Gray Seal]
× Phoca vitulina (♀) [Harbor Seal] CON: northern Atlantic. Mixed matings have been observed in the wild. No hybrids as yet reported. Boness et al. 1993; Wilson 1975.
× Pusa hispida (♀) [Ringed Seal] CHR. CON: northern Atlantic. A newborn hybrid was found dead at Skansen Zoo (Stockholm). It resembled P. hispida. Lönnberg 1929†; Mohr 1940.
Mirounga leonina [Southern Elephant Seal] See: Arctocephalus pusillus.
+ Arctocephalus pusillus [South Africa Fur Seal] An M. leonina male was observed mating with numerous A. pusillus females. He crushed them to death in the process. M. leonina males are far larger than Arctocephalus pusillus females (2,000-2,700 kg vs. 36-122 kg). These seals belong to separate families (Mirounga leonina belongs to Phocidae and Arctocephalus pusillus belongs to Otariidae). Best et al. 1981.
Odobenus rosmarus [Walrus] Walrus populations in the northern Atlantic (Atlantic Walrus, O. r. rosmarus) differ in morphology from those of the northern Pacific (Pacific Walrus, O. r. divergens). A third population (laptevi) which occurs between the ranges of the other two in the Laptev Sea has been treated as a race of both, and as a separate species. This history of treatment, together with its geographic and morphological intermediacy, suggests laptevi as a PHP of crossing between divergens and rosmarus. All three of these walruses were formerly treated as separate species. Fay 1985.
Pagophilus groenlandicus [Harp Seal] See: Cystophora cristata.
Phoca largha [Largha Seal]
× Phoca vitulina [Harbor Seal] CHR(Kamogawa Sea World, Japan). CON: northern Pacific. International Zoo Yearbook 1984/1985 (p. 544), 1986 (p. 494), 1988 (p. 473); Katsumata et al. 2003.
Phoca vitulina [Harbor Seal]
See also: Halichoerus grypus.
+ Enhydra lutris (♂) [Sea Otter] No hybrids of this type have been reported, but along the California coast, matings between southern sea otters (E. l. nereis) and young harbor seal females (weaned pups) have been repeatedly observed (Channel Islands and Monterey Bay). Typically, the sea otter hauls out on the beach near a harbor seal and then harasses it into the water (or accosts it in the water). It then grasps the seal from behind with its teeth and forepaws, bites it on the nose and face, mounts it, and engages in copulatory behavior. Actual intromission frequently occurs (often many times repeated). Such encounters commonly result in the injury, or even death, of the female seal. Harris et al. 2010; Hatfield et al. 1994.
Pusa hispida [Ringed Seal] See: Halichoerus grypus.
Human Origins: Are we hybrids?
On the Origins of New Forms of Life
Cat-rabbit Hybrids: Fact or fiction?
Georges Cuvier: A Biography
Prothero: A Rebuttal
Branches of Biology
By the same author: Handbook of Avian Hybrids of the World, Oxford University Press (2006).