Nesting habitat selection in a fire disturbed area for Spotted Towhee <i>Pipilo maculatus</i>: support for the potential prey site hypothesis

Habitat selection is an important process studied in evolutionary ecology because of its effects on fitness. However, whether it is adaptive remains questionable, especially in disturbed habitats. I investigated nesting habitat To evaluate whether habitat selection was adaptive, I tested two alternative hypotheses using nest survival, which is strongly influenced by nest predation, as a proxy for fitness: 1. The potential prey site hypothesis, that suggests breeding pairs select habitat patches with more potential nest sites, thereby increasing the number of possible nest substrates predators must search, and reducing nest predation rates; 2. The total foliage hypothesis that suggests breeding pairs choose nest sites in habitat patches with dense vegetation to conceal nests and reduce predation risk. I first tested habitat choice and showed that the number of firs (Pseudotsuga menziesii and Abies concolor), locust Robinia neomexicana, and total woody stems were more abundant in nest patches than in random patches. The choice of nest patches with more total stems might suggest support for the total foliage hypothesis. On the other hand, the choice of nest patches with more firs might support the potential prey site hypothesis because they always built their nests in firs. I fit nest survival models to these habitat features and found that daily nest survival increased with the number of firs, supporting the potential prey site hypothesis. However, daily survival rate did not change with the number of total stems, rejecting the total foliage hypothesis. Ultimately, the choice of nest patches with more firs than random patches and the positive directional selection for numbers of firs suggest that habitat selection is adaptive in a fire disturbed area.