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Skeletochronological assessment of age structure and population stability for two threatened frog species

journal contribution
posted on 1999-04-01, 00:00 authored by Don DriscollDon Driscoll
Populations that fluctuate in size may become small at particular times and therefore be at risk of extinction. I used skeletochronology to examine the potential for fluctuations in population size in the threatened frog species Geocrinia alba and Geocrinia vitellina from southwestern Australia. The change in number of lines of arrested growth (LAG) in toe bones of recaptured frogs indicated that most individuals probably gain one LAG annually. Therefore, skeletochronology can be used for age determination. From a combination of skeletochronology and a mark-recapture study, both species appear to live for a maximum of six years. However, the majority of adult males only bred in a single year, which gave rise to a consistently dominant three-year-old age class. A drop in the number of two-year-old frogs and a large increase in the number of three-year-olds (up to 85%) from 1993 to 1994 in both species highlighted the potential for substantial fluctuations in population size. Widespread changes in abundance of between 25 and 50% may therefore be expected over periods as short as one or two years, due to variation in recruitment success.

History

Journal

Austral Ecology

Volume

24

Issue

2

Pagination

182 - 189

Publisher

Wiley-Blackwell Publishing Asia

Location

Richmond, Vic.

ISSN

1442-9985

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

1999, The Author