IUCN Red List Assessment
Red List Category
Red List Criteria
IUCN Evaluation of the Northern Elephant Seal, Mirounga angustirostris
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.
The current population is ~170,000 and growing. The population is renowned for its remarkable growth during the 20th century, following virtual annihilation by sealers in the 19th century. In 2005, 42,589 pups were counted, an increase of 14,699 (53%) over the number observed in 1991. Total population size increased at a rate of 3% from 1991 to 2005.
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.
The total population of this species is probably expanding.
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 Al.
A population reduction is not suspected, although the species is susceptible to El Niño and climate warming may increase its effects.
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 to negligible numbers was observed in the past due to hunting by sealers. Hunting stopped and the population recovered, thus the criteria do not apply.
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 (distribution of colonies) is > 20,000 km². The EOO at sea of foraging individuals is much larger than that.
B2. Area of occupancy (AOO): CR
The AOO (distribution of colonies) is > 2,000 km². The AOO at sea of foraging individuals is much larger than that.
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.
Does not apply for the species.
C. Small population size and decline
Number of mature individuals: CR
Population size is larger than the criteria and is not declining.
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.
Does not apply to the species.
D. Very small or restricted population
Number of mature individuals: CR AND/OR restricted area of occupancy typically: AOO
Most populations are larger than the criteria and are widely distributed.
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. Climate change may impact the population to the point that the probability of extinction may be important but the quantitative value is unknown.
Listing recommendation — The Northern Elephant Seal is increasing and currently expanding its range. Despite past population reductions, this species should now be classified as Least Concern.
- 1996Lower Risk/least concern