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A Video Surveillance System to Monitor Breeding Colonies of Common Terns Sterna Hirundo
Published on: July 22, 2018
Population recovery changes population composition at a major southern Caribbean juvenile developmental habitat for
Jurjan P van der Zee1,2, Marjolijn J A Christianen3,4, Mabel Nava5
1Marine Evolution and Conservation, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborg 7, 9747 AG, Groningen, The Netherlands. j.p.van.der.zee@rug.nl.
Abstract:
Understanding the population composition and dynamics of migratory megafauna at key developmental habitats is critical for conservation and management. The present study investigated whether differential recovery of Caribbean green turtle (Chelonia mydas) rookeries influenced population composition at a major juvenile feeding ground in the southern Caribbean (Lac Bay, Bonaire, Caribbean Netherlands) using genetic and demographic analyses. Genetic divergence indicated a strong temporal shift in population composition between 2006-2007 and 2015-2016 (ϕST = 0.101, P < 0.001). Juvenile recruitment (<75.0 cm straight carapace length; SCL) from the north-western Caribbean increased from 12% to 38% while recruitment from the eastern Caribbean region decreased from 46% to 20% between 2006-2007 and 2015-2016. Furthermore, the product of the population growth rate and adult female abundance was a significant predictor for population composition in 2015-2016. Our results may reflect early warning signals of declining reproductive output at eastern Caribbean rookeries, potential displacement effects of smaller rookeries by larger rookeries, and advocate for genetic monitoring as a useful method for monitoring trends in juvenile megafauna. Furthermore, these findings underline the need for adequate conservation of juvenile developmental habitats and a deeper understanding of the interactions between megafaunal population dynamics in different habitats.
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