IUCN Red List Assessment
Red List Category
Red List Criteria
IUCN Evaluation of the Galápagos Fur Seal, Arctocephalus (australis) galapagoensis
Prepared by the Pinniped Specialist Group
A. Population reduction Declines measured over the longer of 10 years or 3 generations
A1 CR > 90%; EN > 70%; VU > 50%
Al. Population reduction observed, estimated, inferred, or suspected in the past where the causes of the reduction are clearly reversible AND understood AND have ceased, based on and specifying any of the following:
(a) direct observation
(b) an index of abundance appropriate to the taxon
(c) a decline in area of occupancy (AOO), extent of occurrence (EOO) and/or habitat quality
(d) actual or potential levels of exploitation
(e) effects of introduced taxa, hybridization, pathogens, pollutants, competitors or parasites.
Age-structure data are not available for the Galápagos Fur Seal population so the generation time cannot be calculated precisely. With sexual maturity attained at perhaps 5-6 years of age and a maximum longevity of approximately 20 years, the average age of reproducing individuals should be around 10 years. A population reduction of 50% has been estimated for Galápagos Fur Seals over the past 30 years. This meets the criterion for Vulnerable.
A2, A3 & A4 CR > 80%; EN > 50%; VU > 30%
A2. Population reduction observed, estimated, inferred, or suspected in the past where the causes of reduction may not have ceased OR may not be understood OR may not be reversible, based on (a) to (e) under A1.
A population reduction of Galápagos Fur Seals has occurred during the past 30 years. The reasons for the reduction are not clearly understood, but may lie mostly in population effects of the 1982/83 and 1997/98 El Niño events. This meets the criteria for Endangered.
A3. Population reduction projected or suspected to be met in the future (up to a maximum of 100 years) based on (b) to (e) under A1.
A4. An observed, estimated, inferred, projected or suspected population reduction (up to a maximum of 100 years) where the time period must include both the past and the future, and where the causes of reduction may not have ceased OR may not be understood OR may not be reversible, based on (a) to (e) under A1.
A population reduction of around 50% of Galápagos Fur Seals has been estimated over the past 30 years.
B. Geographic range in the form of either B1 (extent of occurrence) AND/OR B2 (area of occupancy)
B1. Extent of occurrence (EOO): CR
The EOO of Galápagos Fur Seals is approximately > 138,000 km².
B2. Area of occupancy (AOO): CR
The AOO of Galápagos Fur Seals is > 120,000 km².
AND at least 2 of the following:
(a) Severely fragmented, OR number of locations: CR = 1; EN (b) Continuing decline in any of: (i) extent of occurrence; (ii) area of occupancy; (iii) area, extent and/or quality of habitat; (iv) number of locations or subpopulations; (v) number of mature individuals.
(c) Extreme fluctuations in any of: (i) extent of occurrence; (ii) area of occupancy; (iii) number of locations or subpopulations; (iv) number of mature individuals.
C. Small population size and decline
Number of mature individuals: CR
The current abundance of Galápagos Fur Seals is roughly known, but is estimated to be about 15,000-20,000.
AND either C1 or C2:
C1. An estimated continuing decline of at least: CR = 25% in 3 years or 1 generation; EN = 20% in 5 years or 2 generations; VU = 10% in 10 years or 3 generations (up to a max. of 100 years in future)
C2. A continuing decline AND (a) and/or (b):
(a i) Number of mature individuals in each subpopulation: CR or
(a ii) % individuals in one subpopulation: CR = 90?100%; EN = 95?100%; VU = 100%
(b) Extreme fluctuations in the number of mature individuals.
D. Very small or restricted population
Number of mature individuals: CR AND/OR restricted area of occupancy typically: AOO
E. Quantitative analysis
Indicating the probability of extinction in the wild to be: Indicating the probability of extinction in the wild to be: CR > 50% in 10 years or 3 generations (100 years max.); EN > 20% in 20 years or 5 generations (100 years max.); VU > 10% in 100 years
There has been no quantitative analysis of the probability of extinction for Galápagos Fur Seals.
Listing recommendation ? Estimates of Galápagos Fur Seal abundance in 1977-1978 suggested a total population size of about 30,000-40,000. Current abundance is estimated to be around 10,000-15,000. The seals are protected within a National Park and the cause of the decline is unclear. Galápagos Fur Seals qualify for listing as Endangered under IUCN criterion A2(a).
- 1996Vulnerable(Baillie and Groombridge 1996)
- 1982Out of Danger(Thornback and Jenkins 1982)