Editorial Type:
Article Category: Research Article
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Online Publication Date: 26 Aug 2019

Multiscale Spatiotemporal Habitat Selection of Northern Cottonmouths

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Page Range: 187 – 195
DOI: 10.1670/18-103
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Abstract

Habitat selection is dependent on several abiotic and biotic factors which have influence at multiple spatial scales. Dependence on specific habitat characteristics for thermoregulation could make habitat selection by herpetofauna especially subtle. Enhancing knowledge of habitat selection by herpetofauna is critical for completely understanding natural histories and improving future habitat management strategies. We conducted a year-long telemetric habitat selection study on two Northern Cottonmouth (Agkistrodon piscivorus) populations in northeast Texas. We used a use–availability approach and investigated intersexual differences at three spatiotemporal scales: home range selection within the study site (home range selection); habitat selection within the home range (macrohabitat selection); and fine-scale local habitat selection (microhabitat selection). The home range selection of both males and females exhibited selection for edges and avoidance of pasture. Males only exhibited macrohabitat selection in the summer, when they selected edge and wetland. Females did not exhibit any macrohabitat selection. Males and females selected microhabitats with thick vegetation in the spring and summer. However, in the fall, male microhabitat selection was influenced by lower temperatures and female microhabitat use appeared to be driven by parturition. Although our study suffered from small female sample size and a short time frame, we provide insight into the complex habitat selection of Cottonmouths in northeast Texas.

Copyright: Copyright 2019 Society for the Study of Amphibians and Reptiles 2019
<sc>Fig</sc>
. 1
Fig . 1

The Texas A&M University–Commerce Artificial Wetland Area (bottom) and the Cooper Lake Wildlife Management Area (top) presented with all macrohabitat types plotted. Stars within the counties represent each wetland's location. Northern Cottonmouth 100% minimum convex polygons are also shown on top of macrohabitat types.


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. 2
Fig . 2

Manly Selection Ratios comparing the proportion of each macrohabitat within 100% minimum convex polygon home ranges to the proportion of each available macrohabitat within the study site (i.e., selection of the home range within the study site; similar to Johnson [1980] second-order selection). A = female A. piscivorus; B = male A. piscivorus.


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Fig . 3

Beta coefficients (±95% CI) from the most-supported microhabitat selection model for males (M) and females (F) during the spring (A), summer (B), and fall (C). Only significant parameters are shown (i.e., parameters with beta coefficients whose 95% CI do not overlap zero). BG = bare ground; CC = canopy cover; CWD = coarse woody debris; DFW = distance from water; GC = ground cover; GT = ground temperature; MVH = maximum vegetation height; SR = sedge and rush.


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Fig . 4

The average distance from water that Cottonmouths were located each month from May 2017 to June 2018 at the Texas A&M University–Commerce Artificial Wetland Area (Commerce, Texas, USA) and the Cooper Lake Wildlife Management Area (Cooper, Texas, USA).


Contributor Notes

Corresponding Author. E-mail: zdelisle@purdue.edu
Accepted: 30 May 2019
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