Factors Affecting Occupancy and Abundance of American Alligators at the Northern Extent of Their Range

Populations of American Alligators (Alligator mississippiensis) generally are considered more abundant at present than historically; however, little information exists to assess the population of alligators in North Carolina at the northern extent of the species' range. Investigation of the fac...

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Bibliographische Detailangaben
Veröffentlicht in:Journal of Herpetology. in. - Society for the Study of Amphibians and Reptiles, 1968. - 50(2016), 4, Seite 541-547
1. Verfasser: Gardner, Beth (VerfasserIn)
Weitere Verfasser: Garner, Lindsey A., Cobb, David T., Moorman, Christopher E.
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2016
Zugriff auf das übergeordnete Werk:Journal of Herpetology. in
Schlagworte:Biological sciences Physical sciences Environmental studies
Beschreibung
Zusammenfassung:Populations of American Alligators (Alligator mississippiensis) generally are considered more abundant at present than historically; however, little information exists to assess the population of alligators in North Carolina at the northern extent of the species' range. Investigation of the factors influencing the distribution and abundance of alligators in North Carolina could shed light on the species' response to rapid environmental change in the region. We conducted a two-phase study: 1) to assess the distribution of alligators in North Carolina using a site-occupancy design; and 2) to assess the patterns in abundance using a repeated sampling design for population estimation. Results showed that both occupancy and abundance decreased in more northern sites, in sites with higher salinity, and in sites that were generally more westward. Sites sampled later in June were more likely to be occupied than those sampled earlier in the month. Abundance also increased with greater shoreline vegetation complexity and varied between lakes, rivers, and estuaries. Compared with studies from 30 years prior, the population seems fairly stable in terms of abundance and distribution. Given the northern limits of the species and the negative association with salinity, continued monitoring is warranted to understand changes in distribution and abundance with respect to predicted rates of sea-level rise, salinization, and urbanization locally around coastal cities like Wilmington.
ISSN:19372418