About the Species
Guadalupe fur seals are members of the “eared seal” family, Otariidae. Their breeding grounds are almost entirely on Guadalupe Island, off the Pacific coast of Mexico, with recent re-colonization of the islands comprising the San Benito Archipelago. A small number of Guadalupe fur seals have also been reported on the northern Channel Islands off California.
Commercial sealers heavily hunted Guadalupe fur seals in the 1700s to the 1800s until they were thought to be extinct in the early 1900s. Dr. Hubbs and Dr. Bartholomew from the University of California rediscovered them breeding in a cave on Guadalupe Island in 1954. The Guadalupe fur seal population has continued to increase from the small remnant group on Guadalupe Island due to protection by the Mexican Government. Guadalupe fur seals are listed as threatened under the Endangered Species Act and depleted under the Marine Mammal Protection Act.
NOAA Fisheries and its partners (including researchers and conservation managers in Mexico) are dedicated to conserving and promoting the recovery of the Guadalupe fur seal population. Researchers use innovative techniques to study and protect this species. For example, they use satellite telemetry to assess movement patterns and foraging activities, interactions between Guadalupe fur seals and fisheries, and their vulnerability to oil spills. This work helps reduce harm from human activities (e.g., fishing) through management based on sound science, public input, and outreach and education.
Population Status
The Guadalupe fur seal population has been growing at approximately 6 percent between 1984 and 2013, based on pup counts at Guadalupe Island. Based on recent surveys, the minimum population abundance estimate for Guadalupe fur seals was estimated at approximately 31,000 animals, thanks in large part to protection under Mexican and U.S. laws.
Learn more about our estimates for population size in our stock assessment reports
Appearance
Guadalupe fur seals' breeding season extends from May through August. Adult males return to the colonies during early June. They set up territories that they defend through aggression and vocalizations when challenged or threatened by other males. Breeding Guadalupe males are polygamous and may mate with and average of 16 females during a single breeding season. Adult females arrive at the colonies in late May, giving birth a few days later. Pups are born from early June through early July, with a peak in late June. An adult female will mate about a week after giving birth to her pup. Weaning occurs around 9 months.
Behavior and Diet
Guadalupe fur seals are generally solitary, are thought to be non-social animals when at sea. They primarily feed at night on coastal and pelagic squid, and small pelagic fish (e.g., mackerel,sardine, and lanternfish) by diving to average depths of 65 feet with maximum depths of about 250 feet. They rest in water with their heads submerged and hind-flippers sticking out.
Where They Live
Guadalupe fur seals live in the waters off southern California and the Pacific coast of Mexico. During the breeding season, they are found in coastal rocky habitats and caves. Little is known about their whereabouts during the non-breeding season.
Guadalupe fur seals generally do not migrate, although they have been documented traveling great distances from their breeding grounds. Their breeding grounds are almost entirely on Guadalupe Island, Mexico, although there are small populations off Baja California on San Benito Archipelago and off southern California at San Miguel Island. It is the only species of the Arctocephalus genus that occurs north of the equator.
Guadalupe fur seals are not common along the West Coast of the United States, but immature animals commonly strand on beaches as far north as Washington State. Over the last several years, a few pups have been born on San Miguel Island in the Channel Islands off southern California.
From archeological findings Guadalupe fur seals were historically found as far north as the northwest Washington coast.
World map providing approximate representation of the Guadalupe Fur Seal range.
Lifespan & Reproduction
Guadalupe fur seals' breeding season extends from May through August. Adult males return to the colonies during early June. They set up territories that they defend through aggression and vocalizations when challenged or threatened by other males. Breeding Guadalupe males are polygamous and may mate with up to 12 females during a single breeding season. Adult females arrive at the colonies in late May, giving birth a few days later. Pups are born from early June through early July, with a peak in late June. An adult female will mate about a week after giving birth to her pup. Weaning occurs around 9 months.
Threats
Entanglement
We have very limited data on the incidental bycatch of Guadalupe fur seals in fishing gear, although some pups and juvenile seals have been documented as entangled, through strandings or fisheries observations. If a fur seal becomes entangled in fishing gear, the animal risks either swimming off with the gear attached or becoming anchored. Once entangled, Guadalupe fur seals may drag and swim with gear attached for long distances, ultimately resulting in fatigue, compromised feeding ability, or severe injury, which may lead to reduced reproductive success and death.
Military Activities
Guadalupe fur seals may be affected by military activities off the U.S. west coast, including readiness training for personnel and their associated fleets and battalions, and construction and maintenance of land-based and island-based facilities. Some of the military training exercises include the use of mid-frequency active sonar for submarine detection, placement and detection of small explosives in coastal waters, open-ocean target practice using high powered guns, ship-shock tests, and other more small-scale exercises. These types of activities can cause temporary or permanent hearing damage or physical injury to Guadalupe fur seals through increased ocean noise and vessel strikes.
Oil Spills
Fur seals rely on their thick layer of fur to insulate their bodies from the cold marine environment. Oil spills pose a threat to this species by affecting the ability of their fur to keep them warm. Guadalupe fur seals rarely strand in southern California, and only recently have we received reports of stranded yearlings, with most of them emaciated or dead. Based on a review of our stranding reports over the last 30 years, there have been no reports of Guadalupe fur seals that have ingested oil or have an oiled pelage.
Ocean Noise
Noise associated with coastal development (e.g., pile driving, dredging, and vessels transporting personnel) could disturb Guadalupe fur seals and cause them to avoid areas temporarily, and may even cause temporary or permanent hearing loss.
Scientific Classification
| Animalia |
Chordata |
Mammalia |
Carnivora |
Otariidae |
Arctocephalus |
townsendi |
Last updated by NOAA Fisheries on 04/10/2024
