| Abstract: | Resource managers often have little information regarding the habitat requirements and distribution of rare species. Factor analysis-based habitat suitability models describe the ecological niche of a species and identify locations where these conditions occur on the landscape using existing occurrence data.We used factor analyses to assess the suitability of habitats for Thamnophis gigas (Giant Gartersnake), a rare, threatened species endemic to the Central Valley of California, USA, and to map the locations of habitat suitable for T. gigas in the Sacramento Valley. Factor analyses indicated that the niche of T. gigas is composed of sites near rice agriculture with low stream densities. Sites with high canal densities and near wetlands also appeared suitable, but results for these variables were sensitive to potential sampling bias. In the Sacramento Valley, suitable habitats occur primarily in the central portion of the valley floor. Based upon the results of the factor analyses, recovery planning for T. gigas will require an on-the-ground assessment of the current distribution and abundance of T. gigas, maintaining the few remaining natural wetlands and the practice of rice agriculture in the Sacramento Valley, and studying the effects of agricultural practices and land use changes on populations of T. gigas. |
| Genre: | Article |
| ProdID: | 70003801 |
| Citation Author: | Halstead, Brian J.; Wylie, Glenn D.; Casazza, Michael L. |
| Citation Contributing Office: | Western Ecological Research Center |
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| Citation End Page: | 599 |
| Citation Issue: | 4 |
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| Citation Language: | English |
| Citation Larger Work Title: | Copeia |
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| Citation Number Of Pages: | 9 |
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| Citation Phsyical Description: | 9 p. |
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| Citation Publisher: | American Society of Ichthyologists and Herpetologists |
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| Citation Search Results Text: | Habitat suitability and conservation of the giant gartersnake (Thamnophis gigas) in the Sacramento Valley of California; 2010; Article; Journal; Copeia; Halstead, Brian J.; Wylie, Glenn D.; Casazza, Michael L. |
| Citation Start Page: | 591 |
| Citation Volume: | 2010 |
| Citation Year: | 2010 |
| Type: | citation/reference |
| Text: | Habitat suitability and conservation of the giant gartersnake (Thamnophis gigas) in the Sacramento Valley of California; 2010; Article; Journal; Copeia; Halstead, Brian J.; Wylie, Glenn D.; Casazza, Michael L. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (INDEX PAGE): | http://www.asihcopeiaonline.org/doi/abs/10.1643/CE-09-199 |
| Date Other: | Tue, 2 Aug 2011 00:00 -0500 |
| Publisher: | American Society of Ichthyologists and Herpetologists |
