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|Species:||Canis latrans x Canis lupus familiaris|
|Canis latrans x Canis lupus familiaris
The prevalence of naturally occurring coydogs is problematic. If interbreeding between the species were common, the coyote population would be expected to acquire more dog-like traits with each successive generation.
Breeding experiments in Germany with poodles and coyotes, as well as with wolves, jackals and later on with the resulting dog-coyote hybrids showed a decrease in fertility and significant communication problems as well as an increase of genetic diseases after three generations of interbreeding between the hybrids, unlike with wolfdogs. This suggests that genetic mutations could be the problem.
Prevalence in the wild
The New York State Department of Environmental Conservation casts doubt on the existence of naturally occurring coydogs in any significant number, at least in New York State, despite the widespread presence of coyotes: "Coyotes and dogs theoretically can interbreed to produce what is called a 'coydog'. However, depending on how much coyote and dog is inherited in the hybrid, crossbreeds with mostly dog genes usually have a reproductive cycle of dogs, not coyotes, and will give birth at times of the year when the pups cannot possibly survive (e.g., January). In addition, there are behavioral differences between most breeds of domestic dogs and coyotes which often prevents crossbreeding from occurring. Coyotes normally mate with other coyotes and not with dogs. [...] Coydogs occurred at the leading edge of coyote range expansion during the 1950 to early 1970's. The occurrence of a coydog would be an extremely rare event in New York today."
The Crane Creek Wildlife Experiment Station of the Ohio Division of Wildlife conducted an analysis of skulls taken from encounters with wild canids in Ohio, cited in The Ohio Journal of Science. "From 1982 to 1988, skull collections were made in 71 counties, yielding 379 (87%) coyotes, 10 (2%) coydogs, and 25 (6%) feral dogs." The figures do not add to 100% because of skull damage hindering positive identification. "The incidence of coydog hybrids was high only in areas of expanding, widely dispersed coyote populations. [...] Mengel (1971) reviewed behavioral and physiological reasons why coydogs are adapted for survival less well than coyotes. These included inappropriate whelping time, lack of parental care by the male, and decreased fertility."[PDF]
- Doris Feddersen-Petersen, Hundepsychologie, 4. Auflage, 2004, Franck-Kosmos-Verlag 2004
- The complicated science of studying coyotes and hybrid species: Mysteries That Howl and Hunt
- Molecular evolution of the dog family - with specifics on chromosome number and hybridization of coyotes and wolves.