Territorial defense by coyotes (Canis latrans) in Yellowstone National Park, Wyoming: who, how, where, when, and why

Abstract

Territorial defense and maintenance are an important facet of the social ecology of most carnivore species. From January 1991 to June 1993, we observed 54 coyotes (Canis latrans) for 2507 h in Yellowstone National Park, Wyoming, during which we observed 112 instances of territory defense. The identity of the coyotes involved in challenging and evicting intruding animals was known. Alpha coyotes were most likely to be involved in territorial evictions of intruding animals, followed by beta individuals; pups participated little in territory defense. Coyotes evicting intruders generally had a numerical advantage when challenging the intruders. Territory-defense rates were highest during and immediately after the breeding season and during the time of pup emergence from the den. All chases of intruders ended at the boundary of the resident coyote pack's territory. Physical contact between the intruding animal and resident pack members occurred with no intruders being killed or seriously injured. Physical contact consisted of fighting and ritualized behaviors, with only a few instances in which fighting led to blood being drawn or minor injuries to the intruder. Most encounters resulted in a hasty retreat from the area by the intruder(s). While indirect means of territory maintenance (i.e., howling and scent-marking) were utilized by resident packs, trespassing still occurred and direct confrontation was needed to enforce boundaries and assert occupancy against other resident packs, as well as against lone intruders seeking territory vacancies. Territoriality was advantageous in that territory holders generally had higher survival rates (except pups), contributed all the reproductive effort to the population, and had greater access to food resources. In contrast, nonterritorial animals had lower survival rates, did not breed, and had reduced access to food (ungulate carcasses) during winter.Résumé : La défense et la conservation du territoire constituent une facette importante de l'écologie sociale de la plupart des espèces de carnivores. De janvier 1991 à juin 1993, nous avons observé 54 coyotes (Canis latrans) pendant 2507 h dans le parc national de Yellowstone, au Wyoming, au cours desquelles nous avons étudié 112 cas de défense de territoire. Les coyotes qui ont défié et chassé des intrus de leur territoire ont été identifiés. Les coyotes alpha sont plus enclins à évincer les intrus de leur territoire, suivis des coyotes bêta; les petits participent peu à la défense territoriale. Les coyotes qui évincent des intrus ont généralement l'avantage numérique lorsqu'ils les poursuivent. La fré-quence des cas de défense territoriale est maximale pendant et immédiatement après la saison de reproduction et au moment de la sortie des petits des terriers. Toutes les poursuites observées ont pris fin à la frontière du territoire de la meute résidante. Les contacts physiques entre intrus et résidants de la meute n'ont jamais abouti à la mort d'un intrus, ni même à des blessures graves. Les contacts physiques se limit...

Space use and social ecology of coyotes (Canis latrans) in a high-elevation ecosystem: relative stability in a changing environment

“…Because resident coyotes are territorial (Camenzind 1978;Bekoff and Wells 1986;Andelt 1985;Gese 2001), it was biologically justified to calculate territories as a single, continuous polygon. Further, visual inspection of GPS collar data indicated that a single, continuous polygon was an appropriate generalization of space use of coyote packs.…”

“…In addition, home range size of resident packs can be influenced by resources or habitat types (Gese et al 1988a). In terms of social ecology, coyote populations can be divided into resident and transient individuals (e.g., Camenzind 1978;Bowen 1982;Bekoff and Wells 1986), but social organization differs among populations, and the way in which an individual transitions into or out of resident packs also varies (Andelt 1985;Gese 2001). Previous studies evaluating coyote social ecology have examined seasonal group size with most of these studies having found the largest coyote group sizes in winter, coinciding with a shift in diet from rodents to ungulates (Camenzind 1978;Bekoff and Wells 1980;Bowen 1981;Andelt 1985;Gese et al 1988b).…”

Coywolf, <em>Canis latrans</em> × <em>lycaon</em>, Pack Density Doubles Following the Death of a Resident Territorial Male

“…Gese (1998) documented a similar shift in the territories of resident Coyote packs following the death of an alpha male in Yellowstone National Park (Wyoming, USA), although no increase in Coyote density was observed. One potential explanation for the original territory in our study being divided is the following: subsequent to the death of the breeding male of the Centerville pack (#0103), there was no dominant male remaining to ward off non-pack members (e.g., see Gese 2001), thereby allowing an influx of Coywolves into the area. Similarly, researchers studying Cougars (Puma concolor) and Black Bears (Ursus americanus) have demonstrated that, in certain instances, killing adult territorial males can cause an influx and hence greater population density of both of these species in a local area (Sargeant and Ruff 2001;Hornocker and Negri 2010: 138, 236, 239).…”

Control of bovine tuberculosis in British livestock: there is no ‘silver bullet’

“…Members of a group might not all participate in intergroup interactions to the same degree; for example, dominant individuals might be more involved in territorial defence than sub-dominants, or males more than females [64,65]. As a result, direct contact both between members of the same social group and between members of different groups can be highly asymmetrical.…”