Little is known about Guadalupe fur seals because they were hunted almost to extinction before researchers began to study them. Being a member of the otariid (sea lion) family, they have external ear flaps and they have long front and hind flippers that allow them to walk when on land. They are similar to northern fur seals in appearance but are slightly smaller, and the males are lighter brown. Adult male Guadalupe fur seals also have a larger head and a long, pointed muzzle. Males reach six feet (1.8 m) and 300 pounds (136 kg), while females grow to four feet (1.2 m) and 100 pounds (43 kg). By looks alone, juvenile Guadalupe fur seals are very difficult to tell apart from juvenile California sea lions and northern fur seals.
There is evidence that Guadalupe fur seals once bred as far North as Point Conception in central California. Due to hunting, they became extinct in California waters by 1825. Today, the only known breeding colony is on Guadalupe Island, off the Mexican coast. Increasing numbers have been seen on California's Channel Islands, and in recent years, several Guadalupe fur seals have stranded along the central California coast. It is not yet known whether these strandings are a result of El Niño events (warmer water pushing their prey northward) or a sign of Guadalupe fur seals returning to their former range.
The breeding strategy of Guadalupe fur seals appears to be similar to that of northern fur seals and other types of sea lions. Males hold territories and breed with many females, and pups are born from mid-June to mid-July. Guadalupe fur seals tend to stay near shore and breed in caves on Guadalupe Island rather than on open beaches. There is evidence that they once bred on the rocky beaches of Guadalupe Island and some scientists speculate that hunting pressure pushed them back into caves for protection.
Little is known about their behavior or their diet, but they seem to eat squid and lanternfish. Guadalupe fur seals are pelagic, living almost all of the time in the open ocean.
Guadalupe fur seals were not identified as a distinct species until 1897. By that time, they were already thought to be extinct. Scientists did not know what a living Guadalupe fur seal looked like until 1928, when a few dozen fur seals were discovered on Guadalupe Island, two of which were brought to the San Diego Zoo. The breeding colony was not reestablished until 1954 and has been growing slowly since then. As a threatened species, the population is estimated to be about 10,000. Guadalupe fur seals are now protected by law in the United States and in Mexico, and Guadalupe Island has been designated a pinniped (seal and sea lion) sanctuary. Hopefully, this protection will restore the Guadalupe fur seal to its former range and we will see them thrive again off the California coast.
At The Marine Mammal Center
The Marine Mammal Center has not rescued many Guadalupe fur seals because they are threatened and are found primarily offshore. From 1975 to 2012, we have rescued 50 Guadalupe fur seals. Similar to northern fur seals, we often rescue underweight pups (especially during El Niño years). In 1998, we rescued an adult female named Emiliano. Because she was the only adult we have ever rescued, we attached a satellite tag to monitor her movements once she was released. She swam back to Guadalupe Island, Mexico within two weeks of being released!
|Pup||< 1 year||< 1 year|
|Weaner||n/a (weaned ~6-9 months)||n/a (weaned ~6-9 months)|
|Yearling||1-2 years||1-2 years|
|Juvenile||n/a (classified as subadults)||n/a (classified as subadults)|
|Subadult||2-3 years||2-3 years|
|Adult||3+ years||3+ years|
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