Unlike most seals, the Guadalupe Seal is a solitary non-social animal. There is a high level of sexual dimorphism, with males being larger than females. Males are polygamous and, on average, will breed with between 5 to 10 females in a season.
As with other species, the male is territorial and will return to the same breeding site for several years in a row. He will guard his smallish piece of turf with vocal displays by coughing and barking. They prefer to breed in caves rather than beaches though there is some speculation that this is due to their persecution from the commercial seal hunts that nearly wiped the species out. Females will arrive a few weeks after the males and give birth shortly afterwards.
Birthing runs from mid June through till the end of July. Pups are born black, but lighten to a tan colour as they mature. Gestation period is around a year and, as with the Cape Fur Seal (Arctocephalus Pusillus) they take relatively long to wean. (Around 9 months)
Guadalupe seals were thought to be extinct in the late 1800's. In 1928 two were spotted off the coast of Mexico.
Total protection from both US and Mexican legislation has seen these seals recover to an estimated population of around 7 000, though there is strain on the gene pool.
In 1997, the first pup was born on San Miguel Island in California.
It is estimated that Guadalupe seals will live between 17 and 20 years. Their main predators are sharks and Killer Whales.
Their Latin name translates as "bear headed."
Guadalupe seals are the rarest of the Fur Seals.
These seals feed almost exclusively at night, diving to a depth of around 20m to catch their favourite prey of squid and fish.
In 1992, the el Nino and Hurricane Darby combined caused a 33% pup mortality. Not good for a species recovering from the brink of extinction.