Coyote Food Habits and Relative Abundance in the Mojave Desert

Worldwide, there has been a growing interest regarding the status and distribution of terrestrial carnivores. As an opportunistic predator, coyotes (Canis latrans) have adapted to most environments, although conflicts between coyotes and humans are an increasing concern for managers in periurban, suburban, and urban areas. Human subsidized food resources can habituate coyotes to urban areas, which can exacerbate human-coyote conflicts. Pet depredation, disease, and rarely, attacks on humans, sometimes occur when humans coexist with coyotes. Additionally, coyotes can pose a threat to populations of rare species, such as the Agassiz’s desert tortoise (Gopherus agassizii). I examined coyote food habits and relative abundance in and surrounding the Marine Corps Air Ground Combat Center (MCAGCC) in Twentynine Palms, CA in spring and fall of 2021. Using macroscopic analysis methods, I examined 536 coyote scat samples and recorded nine different food item groups. Lagomorphs (42%) and rodents (31%) were the most common food item of the seven recognized prey orders. Hair (prey fur) was the most common component in coyote scat (F1,8 = 8.43, P = 0.004) among seasons and study areas. Anthropogenic items were most frequent in the study areas nearest to residential areas (F1,8 = 4.01, P < 0.001), while desert tortoise remains were rare, occurring in <1% of coyote scat (F1,8 = 1.53, P = 0.216) throughout both seasons. Coyotes in the study area primarily consume natural prey items, however anthropogenic food frequency increased in drought conditions. Coyotes rarely consumed desert tortoises in the Twentynine Palms area. I collected coyote scat (n = 1,096) samples in spring (n = 551) and fall (n = 545) using 70 2-km or 1-km transects to quantify scat indices (spring: 2.12 scat/km fall: 2.10 scat/km) to provide an estimate of coyote relative abundance. I evaluated two survey methods for scat density: human-only survey and detection dog-handler (DDH) surveys. Area surveyed by the DDH was approximately three times larger (31.85 km ²) than area surveyed by the human-only (9.49 km²) method. Coyote scats were more frequently discovered in areas near residential areas (F1,8 = 4.77, P < 0.001) which are a likely source of supplemental foods for coyotes via human-subsidized food items. Contrary to previous studies, seasonality did not influence coyote scat index, suggesting that supplemental food resources may assist in supporting coyote populations near residential areas. Greater coyote scat indices in areas closer to wildland-urban interfaces may be a result of anthropogenic food resources (food waste, pet food, water, etc.).