Hostname: page-component-84b7d79bbc-tsvsl Total loading time: 0 Render date: 2024-07-31T10:27:06.476Z Has data issue: false hasContentIssue false

Viability of the southern elephant seal population of the Falkland Islands

Published online by Cambridge University Press:  04 April 2001

F. Galimberti
Affiliation:
Elephant Seals Research Group, Via Buonarroti 35, 20145 Milano, Italy
S. Sanvito
Affiliation:
Department of Biology, Memorial University of Newfoundland, St. John's NF A1B 3X9, Canada
L. Boitani
Affiliation:
Dipartimento di Biologia Animale e dell' Uomo, Università degli Studi di Roma “La Sapienza”, Viale dell' Università 32, 00185 Roma, Italy
A. Fabiani
Affiliation:
Department of Biological Sciences, University of Durham, South Road, Durham DH1 3LE, UK
Get access

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.

Type
Research Article
Copyright
© 2001 The Zoological Society of London

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)