hays-hownumbersof-2017.pdf (765.04 kB)
How numbers of nesting sea turtles can be overestimated by nearly a factor of two
journal contribution
posted on 2017-02-22, 00:00 authored by N Esteban, J A Mortimer, Graeme HaysGraeme HaysEstimating the absolute number of individuals in populations and their fecundity is central to understanding the ecosystem role of species and their population dynamics as well as allowing informed conservation management for endangered species. Estimates of abundance and fecundity are often difficult to obtain for rare or cryptic species. Yet, in addition, here we show for a charismatic group, sea turtles, that are neither cryptic nor rare and whose nesting is easy to observe, that the traditional approach of direct observations of nesting has likely led to a gross overestimation of the number of individuals in populations and underestimation of their fecundity. We use high-resolution GPS satellite tags to track female green turtles throughout their nesting season in the Chagos Archipelago (Indian Ocean) and assess when and where they nested. For individual turtles, nest locations were often spread over several tens of kilometres of coastline. Assessed by satellite observations, a mean of 6.0 clutches (range 2-9, s.d. = 2.2) was laid by individuals, about twice as many as previously assumed, a finding also reported in other species and ocean basins. Taken together, these findings suggest that the actual number of nesting turtles may be almost 50% less than previously assumed.
History
Journal
Proceedings of the Royal Society B: biological sciencesVolume
284Issue
1849Article number
20162581Pagination
1 - 7Publisher
Royal Society PublishingLocation
London, Eng.Publisher DOI
Link to full text
ISSN
0962-8452eISSN
1471-2954Language
engPublication classification
C Journal article; C1 Refereed article in a scholarly journalCopyright notice
2017, The AuthorsUsage metrics
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chagoscheloniaargosfastloc-GPSclutch frequencycritically endangeredScience & TechnologyLife Sciences & BiomedicineBiologyEcologyEvolutionary BiologyLife Sciences & Biomedicine - Other TopicsEnvironmental Sciences & EcologyCHELONIA-MYDASGREEN TURTLESDERMOCHELYS-CORIACEACARETTA-CARETTAMARINE TURTLESCOSTA-RICAPOPULATIONCONSERVATIONPACIFICOCEAN
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