National Marine Mammal Laboratory, National Marine Fisheries Service, 7600 Sand Point Way, N.E., Seattle, Washington 98115.
MODELING AGE-SPECIFIC MORTALITY FOR MARINE MAMMAL POPULATIONS
Article first published online: 26 AUG 2006
Marine Mammal Science
Volume 7, Issue 1, pages 50–65, January 1991
How to Cite
Barlow, J. and Boveng, P. (1991), MODELING AGE-SPECIFIC MORTALITY FOR MARINE MAMMAL POPULATIONS. Marine Mammal Science, 7: 50–65. doi: 10.1111/j.1748-7692.1991.tb00550.x
- Issue published online: 26 AUG 2006
- Article first published online: 26 AUG 2006
- Received: November 23, 1988 Accepted: May 29, 1990
- mortality estimation;
- survival rates;
- Leslie matrix;
A method is presented for estimating age-specific mortality based on minimal information: a model life table and an estimate of longevity. This approach uses expected patterns of mammalian survivorship to define a general model of age-specific mortality rates. One such model life table is based on data for northern fur seals (Callorhinus ursinus) using Siler's (1979) 5-parameter competing risk model. Alternative model life tables are based on historical data for human females and on a published model for Old World monkeys. Survival rates for a marine mammal species are then calculated by scaling these models by the longevity of that species. By using a realistic model (instead of assuming constant mortality), one can see more easily the real biological limits to population growth. The mortality estimation procedure is illustrated with examples of spotted dolphins (Stenella attenuata) and harbor porpoise (Phocoena phocoena).