Date of Award:

5-2010

Document Type:

Dissertation

Degree Name:

Doctor of Philosophy (PhD)

Department:

Wildland Resources

Advisor/Chair:

John A. Shivik

Abstract

A common observation in animal space use studies is that animals do not use space uniformly, but rather use some areas of their home ranges and territories with much higher intensity than others. Numerous methods have been developed to estimate these "core areas"; however, all of the current methods available are based on arbitrary rules. Additionally, most studies do not attempt to understand what behavioral processes lead to the observed patterns of non-uniform space use. This study has four main objectives: 1) to develop an objective and more precise method for estimating core areas, 2) to understand the processes leading to unequal coyote capture probabilities across territories, 3) to understand the biological mechanisms that influence the location of bobcat core areas, and 4) to determine how differences in territory size affect coyote movement patterns. The core area estimation method I developed consistently performed better than methods using arbitrary values to define core areas. Using this method to estimate coyote core areas, I determined that coyote capture locations were not actually biased towards low use areas because of low familiarity with those areas, but rather because of a higher probability of encountering traps there. Intensity of coyote use did, however, influence the location of bobcat core areas. When prey abundance was high, bobcat core areas were located in areas of low coyote use but occurred in areas of high coyote use when prey abundance was low, indicating bobcat core areas are the result of at least two processes: foraging conditions and avoidance of intraguild predation. Lastly, coyote movement behavior changed significantly as territory size increased, leading to faster and straighter movement patterns. However, even though coyotes in larger territories moved twice as fast as those in small territories, they took significantly longer to traverse their territories compared to those in small territories. This might be the result of coyotes occupying large territories being less constrained by defense due to lower conspecific density compared to coyotes occupying small territories. Overall, my research reveals the importance of using more precise methods to delineate animal space use patterns, and the greater information researchers can obtain when they attempt to understand the processes underlying space use patterns.

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