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How numbers of nesting sea turtles can be overestimated by nearly a factor of two

Nicole Esteban Orcid Logo, Jeanne A. Mortimer, Graeme C. Hays

Proceedings of the Royal Society B: Biological Sciences, Volume: 284, Issue: 1849, Start page: 20162581

Swansea University Author: Nicole Esteban Orcid Logo

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DOI (Published version): 10.1098/rspb.2016.2581

Abstract

Estimating 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 difficu...

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Published in: Proceedings of the Royal Society B: Biological Sciences
ISSN: 0962-8452 1471-2954
Published: 2017
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URI: https://cronfa.swan.ac.uk/Record/cronfa31973
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spelling 2020-08-06T14:40:03.7879706 v2 31973 2017-02-14 How numbers of nesting sea turtles can be overestimated by nearly a factor of two fb2e760b83b4580e7445092982f1f319 0000-0003-4693-7221 Nicole Esteban Nicole Esteban true false 2017-02-14 SBI Estimating 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 10s of km of coastline. Assessed by satellite observations, a mean of 6.0 clutches (range 2-9, SD=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 often the actual number of nesting turtles may be almost 50% less than previously assumed. Journal Article Proceedings of the Royal Society B: Biological Sciences 284 1849 20162581 0962-8452 1471-2954 Chagos, Chelonia, Argos, Fastloc-GPS, clutch frequency, critically endangered 22 2 2017 2017-02-22 10.1098/rspb.2016.2581 COLLEGE NANME Biosciences COLLEGE CODE SBI Swansea University 2020-08-06T14:40:03.7879706 2017-02-14T11:16:14.3901245 Nicole Esteban 0000-0003-4693-7221 1 Jeanne A. Mortimer 2 Graeme C. Hays 3 0031973-14022017114931.pdf Esteban-2017_PRSB_accepted.pdf 2017-02-14T11:49:31.6930000 Output 902308 application/pdf Accepted Manuscript true 2017-02-15T00:00:00.0000000 true eng
title How numbers of nesting sea turtles can be overestimated by nearly a factor of two
spellingShingle How numbers of nesting sea turtles can be overestimated by nearly a factor of two
Nicole Esteban
title_short How numbers of nesting sea turtles can be overestimated by nearly a factor of two
title_full How numbers of nesting sea turtles can be overestimated by nearly a factor of two
title_fullStr How numbers of nesting sea turtles can be overestimated by nearly a factor of two
title_full_unstemmed How numbers of nesting sea turtles can be overestimated by nearly a factor of two
title_sort How numbers of nesting sea turtles can be overestimated by nearly a factor of two
author_id_str_mv fb2e760b83b4580e7445092982f1f319
author_id_fullname_str_mv fb2e760b83b4580e7445092982f1f319_***_Nicole Esteban
author Nicole Esteban
author2 Nicole Esteban
Jeanne A. Mortimer
Graeme C. Hays
format Journal article
container_title Proceedings of the Royal Society B: Biological Sciences
container_volume 284
container_issue 1849
container_start_page 20162581
publishDate 2017
institution Swansea University
issn 0962-8452
1471-2954
doi_str_mv 10.1098/rspb.2016.2581
document_store_str 1
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description Estimating 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 10s of km of coastline. Assessed by satellite observations, a mean of 6.0 clutches (range 2-9, SD=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 often the actual number of nesting turtles may be almost 50% less than previously assumed.
published_date 2017-02-22T03:39:06Z
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