Sie können Bookmarks mittels Listen verwalten, loggen Sie sich dafür bitte in Ihr SLUB Benutzerkonto ein.
Medientyp:
E-Artikel
Titel:
Evaluating the effect of varying clutch frequency in nesting trend estimation of sea turtles
Beteiligte:
Matsinos, Yiannis;
Mazaris, Antonios;
Pantis, John
Erschienen:
Brill, 2008
Erschienen in:
Amphibia-Reptilia, 29 (2008) 3, Seite 361-369
Sprache:
Nicht zu entscheiden
DOI:
10.1163/156853808785111968
ISSN:
0173-5373;
1568-5381
Entstehung:
Anmerkungen:
Beschreibung:
AbstractIn sea turtle studies, population trend assessments are primarily based on monitoring of beach nesting. Annual nesting abundances are usually estimated by dividing the total number of nests laid during a season by the mean number of clutches deposited annually by nesting turtles, termed clutch frequency. The estimated numbers of annual nester are used for drawing population trends. In the present study, we evaluate the potential effect of individual variability in clutch frequency and successful nest construction, in estimating annual nesting abundance and nesting population trends. We estimate annual nesting abundance and trends by using constant values of clutch frequency. We further develop a stochastic model that simulates breeding performance as an individual based process to produce estimates of annual female abundances. As the next step, we draw population trends by using abundance estimates produced by the model. Our results indicate that nesting abundance estimations are highly affected by stochasticity in nesting behavior. Long term nesting population trends followed annual fluctuations in nester abundance, leading to a great variability in the produced patterns. Our results indicate that population trend estimations which are based on observed numbers of females nesting annually and mean values of clutch frequency are unreliable due to the exclusion of stochastic events that increment nesting performance, thus should be viewed with increased caution. We conclude that more data are needed to be collected in order to produce accurate estimates of sea turtle nesting population tends.