Seasonal Changes in Coyote Food Habits as Determined by Fecal Analysis

Abstract

Feces were analyzed to determine the food habits of coyotes (Canis latrans) in Cuyamaca Rancho State Park, San Diego Co., California. Of 748 food items identified from 223 scats, mammals made up 53 %, vegetation 23 %, arthropods 9%, reptiles 1 %, birds 1 % and miscellaneous items 3 %. Percent relative frequency of mammalian food items decreased significantly from winter (78%) to summer (52 %). Conversely percent of arthropod remains in summer scats ( 1 o%) increased significantly from winter scats (0%). Percent occurrence of vegetation in feces also increased significantly from winter (12%) to summer (22 %). Observations of coyotes did not vary significantly between seasons. These results suggest that coyotes feed opportunistically in Cuyamaca Rancho State Park. INTRODUCTION Past studies of coyote (Canis latrans) food habits (Bond, 1934; Murie, 1940, 1951; Ferrel et al., 1953; Fichter et al., 1955; Korschgen, 1957; Gipson, 1974; Holle, 1978; Johnson and Hansen, 1978; Litvaitis and Mautz, 1980) prompted some authors to categorize the feeding behavior of coyotes as opportunistic (Murie, 1945; Fichter et al., 1955; Nellis and Keith, 1976; Bekoff, 1977; Litvaitis and Shaw, 1980), whereas others suggested their feeding was highly selective (Clark, 1972; Johnson and Hansen, 1979; Todd et al., 1981). Seasonal variation in the food habits of coyotes has been welldocumented (Ferrel et al., 1953; Fichter et al., 1955; Korschgen, 1957; Bowen, 1981), but limited data are available for southern California. The purpose of this study was to examine seasonal fluctuations in the number of coyotes in relation to corresponding changes in their food habits. STUDY AREA East Mesa is located in Cuyamaca Rancho State Park, San Diego Co., Calif., at an elevation of 1525 m. This area consists of extensive upland meadows, intermixed with stands of oak (Quercus kelloggii and Q agrifolia) and pine (Pinusjeffreyi) and is surrounded by dense chaparral. Bowyer and Bleich (1980) provide a more complete description of this area. METHODS Scats were collected along a 8.2-km dirt road on East Mesa on 268 days from June 1977 throughJanuary 1979. Sightings of 278 coyotes occurred along this fixed transect throughout the sampling period. Scats were stored in paper bags, and location, date and method of scat identification were recorded. Coyote feces were identified by their characteristic morphology and the presence of coyote tracks nearby. For laboratory analyses, scats were placed in nylon stockings and thoroughly rinsed under tap water. Remains were spread across a dissection pan and carefully examined with a dissection microscope for food items. Additionally, four or five random points were examined for food items in each pan. Mammalian species were identified from hair morphology as Present address: Center of Environmental Sciences, Unity College, Unity, Maine 04988.