Viability of the southern elephant seal population of the Falkland Islands

• Published in: Animal Conservation
• Main Authors: Galimberti, F., Sanvito, S., Boitani, L., Fabiani, A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2001
• Subjects: Elephant Seal; Elephant Seals; Southern Elephant Seal; Southern Elephant Seals
• Online Access: http://dx.doi.org/10.1017/s1367943001001093; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1017%2FS1367943001001093; https://zslpublications.onlinelibrary.wiley.com/doi/pdf/10.1017/S1367943001001093

Abstract Accurate long‐term series of demographic data are available for most populations of southern elephant seals. However, research on the elephant seals of the Falkland Islands began only recently, and information for an accurate forecasting of the future of this population is lacking. In this paper we present data on the current status of the population and its trend in size during the last 11 years. We built an age‐structured model of the population and analyzed the effect of variation in demographic parameters on population growth. Elasticity analysis demonstrated that variation in mortality has a more pronounced effect on instantaneous growth rate than an equivalent variation in fecundity. We examined the effects of environmental variability, inbreeding and catastrophes on population viability by a computer simulation using the VORTEX PVA programme. In the stochastic model, the most important factor affecting extinction risk was variability in mortality rates, in particular of the adult classes. We concluded that, although the population does not appear to be at immediate risk of extinction, its small size and isolation make it necessary to accurately monitor the population trends and to acquire additional information on life history and feeding strategies.