Marilyn Knight, M.S., 2001
(Wildlife Technician, North Carolina Wildlife Resources Commission)Department of Biology
Murray State University, Murray, KY 42071
Diet analysis of re-introduced red wolves (Canis rufus) in northeastern North Carolina.ABSTRACT :
Upon passage of the Endangered Species Act of 1973, the U.S. Fish and Wildlife Service established a priority management program to bring the red wolf (Canis rufus) back from the brink of extinction through capture, captive breeding, and reintroduction. Initially re-established in 1987, approximately 55-70 red wolves currently thrive in northeastern North Carolina. From January 1993 through December 1995, 648 red wolf scats were collected and analyzed for composition of diet. I identified the mammalian prey items consumed by wolves using characteristics of hair and teeth found in the residue remaining after fecal material was washed out of the samples. I analyzed my data by year, season, habitat, and relative pack age using two methods of calculation: frequency of occurrence and average amount of biomass per scat for each species of prey. I performed a series of two-way analyses of variance to identify the presence of interaction between factors. If there was no evidence of two-way interaction, differences in diet were tested for statistical significance by comparing the mean amount of a particular species of prey (kg) recovered per scat in a series of one-way analyses of variance with season, year, habitat, and relative pack age as the independent variables. Four primary prey items were identified in decreasing order of importance: small rodents, primarily hispid cotton rats (Sigmodon hispidus) and house mice (Mus musculus); white-tailed deer (Odocoileus virginianus); rabbit (Sylvilagus floridanus and Sylvilagus palustris); and raccoon (Procyon
lotor). The frequency of occurrence of all four primary prey taxa was found to differ significantly by year, season, habitat, and relative pack age. According to analyses of mean biomass of prey per scat, I found evidence for annual variation in the consumption of white-tailed deer, raccoon, and small rodents. Small rodents appeared to be more important in the diet in 1995 than during other years, except in those samples representing the spring season, and least important in 1994. Annual differences in the consumption of white-tailed deer were significantly greater in spring of 1995 than in spring of 1994. The mean biomass of raccoon and rabbit per scat did not vary seasonally, but that of small rodents showed significant variation by season, with larger quantities being consumed in winter of 1995 than in summer of that year. The mean biomass of white-tailed deer was significantly greater in spring of 1995 than in winter of 1995. There were significant differences in the mean biomass of small rodents per scat among habitat types and of white-tailed deer and small rodents among relative pack ages. Packs using primarily agricultural areas consumed greater amounts of rodents and less deer than did packs inhabiting non-agricultural areas. Likewise, young packs consumed more rodents and less deer than did old packs. The mean biomass of raccoon and rabbit per scat was similar in agricultural and non-agricultural habitats, and no significant differences in amounts of these species consumed were detected between packs with a young age structure and packs of older age structure. Overall, diets appeared to differ due to wolf pack habitat utilization and age structures. Annual and seasonal differences in diet were evident, as well. Future dietary studies of red wolves should examine prey availability in order to gain a better understanding of annual and seasonal variations.
Constructed by Brandon Kellie on 6/26/01.
