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Journal Article

Analyzing temporally correlated dolphin sightings data using generalized estimating equations

Helen Bailey; Ross Corkrey; Barbara Cheney; Paul M. Thompson
Marine Mammal Science · Vol. 29, Issue 1 · pp. 123-141 · 2013

Abstract

A bstract Many of the statistical techniques commonly used in ecology assume independence among responses. However, there are many marine mammal survey techniques, such as those involving time series or subgroups, which result in correlations within the data. Generalized estimating equations (GEEs) take such correlations into account and are an extension of generalized linear models. This study demonstrates the application of GEEs by modeling temporal variation in bottlenose dolphin presence from sightings data. Since dolphins could remain in the study area for several hours resulting in temporal autocorrelation, an autoregressive correlation structure was used within the GEE, each cluster representing hours within a day of survey effort. The results of the GEE model showed that there was significant diel, tidal, and interannual variation in the presence of dolphins. Dolphins were most likely to be seen in the early morning and during the summer months. Dolphin presence generally peaked during low tide, but this varied among years. There was a significantly lower probability of dolphins being present in 2003 than 2004, but not between 2004 and the other years (1991, 1992, and 2002). GEE‐model fitting packages are now readily available, making this a valuable, versatile tool for marine mammal biologists.

Bibliographic Information

JournalMarine Mammal Science
PublisherWiley
Publication Date2013-01-01
Publication Year2013
Volume29
Issue1
Pages123-141
Document TypeJournal Article
Print ISSN0824-0469
eISSN1748-7692
DOI10.1111/j.1748-7692.2011.00552.x
SubjectMarine Biology

Access Information

NARA Access Coverage1997-01-01~Current
Journal Homepagehttps://onlinelibrary.wiley.com/loi/17487692
Publisher PageOpen Publisher Page
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