Literaturdatenbank
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Sherwood, N. R. (2011). Habitat selection criteria by wood turtle, glyptemy insculpta, in new jersey. Unpublished thesis , Montclair University, Montclair, NJ.
Added by: Sarina Wunderlich (25 Jun 2011 12:42:03 UTC) |
| Resource type: Thesis/Dissertation BibTeX citation key: Sherwood2011 View all bibliographic details  |
Categories: General Keywords: Emydidae, Glyptemys, Glyptemys insculpta, Habitat = habitat, Nordamerika = North America, Schildkröten = turtles + tortoises Creators: Sherwood Publisher: Montclair University (Montclair, NJ) |
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| Abstract |
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Due to habitat loss and collection for pet trades in the early 1900s, the wood turtle, Glyptemys insculpta, in New Jersey declined rapidly. The species has been listed by the State of New Jersey as a threatened species since 1979. Wood turtle collection was made illegal in New Jersey; however, the major and growing threats to this species (habitat loss, fragmentation and alteration) continues, which makes their protection and conservation efforts necessary for the preservation of this species. Understanding its habitat selection preference will improve agencies’ capacity of wood turtle conservation via identifying essential wood turtle habitats across Northern New Jersey and increasing connectivity of their habitats. This study utilized paired logistic regression to determine habitat selection criteria by wood turtles. The paired logistic regression requires comparisons of habitat characteristics between turtle activity areas with characteristics of reference areas where no turtle activity was recorded; a reference area was selected to pair with each selected activity area. Turtle activity areas were selected from 2007 wood turtle tracking data collected by New Jersey Department of Environmental Protection, Endangered and Nongame Species Program (ENSP). A 100 m2 (10 m x 10 m) plot was established for each site. The availability of potential food sources, (berries, mushrooms, moss, and invertebrates), as well as habitat features (leaf litter depth, distance to water, distance to reference areas, distance to disturbance, percent canopy cover, tree richness, percent organic in soil, and percent organic in leaf litter) were surveyed. All eleven variables were tested in two stepwise model selection procedures using a statistical program, Statistical Analysis System (SAS). Model 1 used continuous values for nine variables (berries, moss, mushrooms, invertebrates, tree richness, distance to water, distance to disturbance, and percent organic content in soil and leaf litter) and two were categorical (leaf litter depth and percent canopy cover). Model 2 used presence (1) and absence (0) values for food items (berries, mushroom, moss and invertebrates), categorical values were used for two variables (leaf litter depth and percent canopy cover) and continuous values were used for the five remaining variables (tree richness, distance to water, distance to disturbance, and percent organic content in soil and leaf litter). For model 1, among the eleven variable, three (distance to water, invertebrates, and mushrooms) were considered significant variables. For model 2, among the eleven variables, three (distance to water, invertebrates, and percent canopy cover) were considered significant variables. The results of both models suggest wood turtles prefer areas close to water with a high invertebrate occurrence.
Added by: Sarina Wunderlich |