Lesser prairie-chicken habitat selection across varying land use practices in Eastern New Mexico and West Texas
Borsdorf, Philip K. K.
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The primary focus of this thesis was to assess gender-specific lesser prairie-chicken breeding season home range size and habitat selection. Data were collected on two different study areas occurring in sand-shinnery oak grassland communities on the Southern High Plains. From 2008-2012, on a study area occurring in west Texas (Chapter 2), male lesser prairie-chickens demonstrated selection for vegetative cover-types comprised of sand-shinnery oak, but dominated by native prairie-grasses, while females used the cover-types in proportion to availability. On experimentally tebuthiuron treated (0.6 kg/ha) and rotationally grazed plots in eastern New Mexico (Chapter 3), results suggested selection by male lesser prairie-chickens for areas not treated with tebuthiuron in comparison to tebuthiuron treated areas. Female lesser prairie-chickens, in New Mexico, used the not-treated and not-grazed areas in greater proportion to availability, the treated and not-grazed, and not-treated and grazed areas in proportion to availability, and the treated and grazed areas less than were proportionally available. Gender-specific home range size was assessed for lesser prairie-chickens from 2008-2012 on the west Texas study area (Chapter 2). Three different home range estimators were used; 95% fixed kernel density estimates using two different bandwidths (LSCV and Plug-in) and a 100% Minimum Convex Polygon were implemented to estimate home range sizes. For male lesser prairie-chickens, both 95% fixed kernel density estimates (LSCV and Plug-in) were significantly larger than 100% MCP home ranges. For female lesser prairie-chickens, only the 95% fixed kernel density (LSCV) estimates were significantly larger than 100% MCP home ranges. Despite the home range estimator, all female home ranges were approximately twice the size of male home ranges. Nocturnal roosting site selection was assessed in relation to microhabitat and microclimate in west Texas during the breeding seasons of 2011 and 2012 (Chapter 4). There were no differences in visual obstruction readings between roost and paired random sites. Lesser prairie-chickens roosted directly on bareground with no overhead vegetative coverage. In 2011, there was significantly more bareground and less humidity (% relative humidity) at roosting site point center compared to paired random sites. In 2012, roost and random sites were equally humid, but there was more litter coverage surrounding roosting sites compared to paired random sites. Temperature did not appear to differ between roost and random sites in either 2011 or 2012. Results may show evidence for the selection of nocturnal roosting sites based on tradeoffs between visual and/or scent concealment from nocturnal predators as related to the available microclimate and microhabitat variables during the course of this study.