Consequences of woody plant encroachment for mammalian predator

Woody plant encroachment is a widespread process of land cover change from grass- to woody plant-dominated habitats that has been observed in arid and semiarid ecosystems around the world. Woody plant encroachment affects ecosystem characteristics, including plant resource availability and microclimate, and it has the potential to have bottom-up effects on a wide range of animals through changes in habitat structure and the abundance and species richness of prey. Little is known about the impact that woody plant encroachment may have on the ecology of mammalian predators. This dissertation begins by assessing the consequences of woody plant encroachment for mammalian predator ecology globally and then focuses on the ecology of a widely distributed, North American predator, the coyote (Canis latrans).;A dataset containing information on the global distribution of mammals was used to generate a list of carnivores found in woody plant-encroached areas. Noninvasive genetic sampling and carbon isotope techniques were used to assess the individual-specific feeding ecology of coyotes at the Sevilleta National Wildlife Refuge (NWR) and Long Term Ecological Research (LTER) site in central New Mexico, USA. The specific objective was to determine whether woody plant encroachment, which has occurred over the past century at the Sevilleta NWR, has led to a shift in the base of the coyote food chain from native C4 grasses to encroaching C3 woody plants. Habitat characteristics associated with woody plant encroachment were assessed at multiple spatial scales to determine whether spatial scale has an impact on the observed relationship between coyote feeding ecology and woody plant encroachment.;At least 97 mammalian carnivores are found in woody plant-encroached areas. Spatial scale affects the strength of the relationship between coyote feeding ecology and woody plant encroachment. A significant shift in the base of the coyote food chain from C4 grasses to C3 plants was observed only when habitat characteristics were evaluated at a small spatial scale. Further research regarding the effects of woody plant encroachment on mammalian predator ecology, especially on predator fitness and the ecology of specialized predators, is needed.