Accounting for Imperfect Detection Is Critical for Inferring Marine Turtle Nesting Population Trends

Pfaller, Joseph B., Bjorndal, Karen A., Chaloupka, Milani, Williams, Kristina L., Frick, Michael G. and Bolten, Alan B. (2013) Accounting for Imperfect Detection Is Critical for Inferring Marine Turtle Nesting Population Trends. PLoS One, 8 4: e62326.1-e62326.5. doi:10.1371/journal.pone.0062326

Author Pfaller, Joseph B.
Bjorndal, Karen A.
Chaloupka, Milani
Williams, Kristina L.
Frick, Michael G.
Bolten, Alan B.
Title Accounting for Imperfect Detection Is Critical for Inferring Marine Turtle Nesting Population Trends
Journal name PLoS One   Check publisher's open access policy
ISSN 1932-6203
Publication date 2013-04
Sub-type Article (original research)
DOI 10.1371/journal.pone.0062326
Open Access Status DOI
Volume 8
Issue 4
Start page e62326.1
End page e62326.5
Total pages 5
Place of publication San Francisco, CA United States
Publisher Public Library of Science
Collection year 2014
Language eng
Formatted abstract
Assessments of population trends based on time-series counts of individuals are complicated by imperfect detection, which can lead to serious misinterpretations of data. Population trends of threatened marine turtles worldwide are usually based on counts of nests or nesting females. We analyze 39 years of nest-count, female-count, and capture-mark-recapture (CMR) data for nesting loggerhead turtles (Caretta caretta) on Wassaw Island, Georgia, USA. Annual counts of nests and females, not corrected for imperfect detection, yield significant, positive trends in abundance. However, multistate open robust design modeling of CMR data that accounts for changes in imperfect detection reveals that the annual abundance of nesting females has remained essentially constant over the 39-year period. The dichotomy could result from improvements in surveys or increased within-season nest-site fidelity in females, either of which would increase detection probability. For the first time in a marine turtle population, we compare results of population trend analyses that do and do not account for imperfect detection and demonstrate the potential for erroneous conclusions. Past assessments of marine turtle population trends based exclusively on count data should be interpreted with caution and re-evaluated when possible. These concerns apply equally to population assessments of all species with imperfect detection
Keyword Capture Recapture Data
Breeding Bird Survey
Temporary Emigration
Robust Design
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2014 Collection
School of Biological Sciences Publications
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