For northeastern coyotes, hybridization with the dog was estimated to have occurred between 11 and 24 generations ago, and there is no evidence of recent dog-coyote crossing. There was some evidence of first and second generation wolf-coyote hybrids back-crossing with coyotes. For Ohio coyotes, the wolf DNA was present in the nuclear genome but not the mitochondrial genome, indicating hybridization between male wolves and female coyotes. For northeastern coyotes, the dog DNA was present in the nuclear genome but not the mitochondrial genome, indicating hybridization between male dogs and female coyotes. Although hundreds of northeastern coyotes showed maternal wolf DNA, nearly all were the same haplotype that indicated a past single hybridization between a female wolf and a male coyote. These findings support the hypothesis of sexual interaction based on body size, with the larger species male almost always crossing with the smaller species female.
