Date of Award:

2013

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Wildland Resources

Advisor/Chair:

Eric M. Gese

Abstract

Valles Caldera National Preserve (VCNP) managers were concerned about low elk recruitment observed at the same time as an apparent increase in sightings of coyotes and observations of coyote predation on elk calves. The goal of this study was to describe coyotes’ ecological interactions with elk, particularly coyote diet and movements on the Valle Grande, a large grassland meadow in the southeastern portion of the VCNP.

We examined coyote diet by quantifying undigested remains of food items in coyote scats (feces). The most frequent taxa were rodents (montane voles and pocket gophers), elk (adult and calf), insects (grasshoppers and beetles), mountain cottontail rabbits, and plants. Most food types varied significantly seasonally and annually, likely due to climatic variation and the relative availability or vulnerability of food items. In particular, an increase in calf elk consumed during summer 2006 followed a dry winter when elk may have been in a lower nutritional state.

We analyzed locations of 33 coyotes, obtained via global positioning system (GPS) collars and radio-tracking. We classified 23 coyotes as residents, living with a social group in a defined area (11.0 km2 mean), and 10 coyotes as transient, with less fidelity to specific areas and often travelling around the edges of the areas occupied by the four resident packs. Coyotes spent most of their time in dry meadow habitat. Coyotes spent more time in riparian habitat than expected based on its availability within home range and less time in forests. We found no relationship between coyote social cohesion (proximity of pack members to each other) and the proportion of elk in coyote diets. We concluded that coyote sociality on VCNP was relatively stable year-round despite changes in biological needs and prey size.

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