Coywolf

Abstract: The eastern Coyote or Coywolf ( Canis latrans × C. lycaon ) inhabiting northeastern North America resulted from hybridization between the expanding population of the western Coyote ( Canis latrans ) and the remnant population of Eastern Wolf ( C. lycaon ) and possibly domestic dogs ( C. lupus familiaris ) in the early 20th century. This study compares the body mass of eastern (i.e., northeastern) Coyotes, western Coyotes, and Eastern Wolves and synthesizes the recent literature to gain better insight into the taxonomic relations and differences of closely-related Canis species. Northeastern Coyotes (males = 16.5 kg; females = 14.7 kg) were statistically ( P < 0.0001) intermediate in mass between western Coyotes (males = 12.2 kg; females = 10.7 kg) and Eastern Wolves (males = 28.2 kg, females = 23.7 kg), consistent with their hybrid origin, but were numerically closer to western Coyotes. Large Cohen’s d (3.00–8.56), (0.915–0.929), and Cohen’s f (3.28–3.62) values indicated large effect sizes from the body mass comparisons. Eastern Wolves were 61–71% heavier than the same sex in the northeastern Coyotes, which in turn were ca. 35–37% heavier than the same sex in the western Coyotes. Alternatively, western Coyotes were 73–74% of the size of the same sex in the northeastern Coyotes, which in turn were 59–62% of the size of the same sex in the Eastern Wolves. I also attempted to relate mitochondrial DNA (mtDNA) haplotypes to body mass. Six of 17 (35.3%) adult female northeastern Coyotes captured in Massachusetts weighed ≥18 kg, heavier than any other described Coyote from outside northeastern North America. Mitochondrial DNA haplotypes associated with these heavy female northeastern canids were C9 = 4, C19 = 1, and C48 = 1. Body mass (kg) and mtDNA haplotype data of 53 northeastern Coyotes (males = 28, females = 25) showed no difference between haplotype and body mass for males ( P < 0.852) or females ( P < 0.128), suggesting that there is not a particular haplotype (e.g., C1) that is associated with the heavier animals. I propose that the most appropriate name for this hybrid animal is Coywolf ( Canis latrans × C. lycaon ), rather than a type of Coyote. Coywolves are distinct, being larger than any other population of Coyotes but smaller than Eastern Wolves. I propose that the 5 distinct types of Canis be recognized as: western Coyote, Coywolf (northeastern Coyote), Eastern Wolf (including Red Wolf C. rufus ), Gray × Eastern Wolf hybrids (‘Great Lakes’ Wolves; C. lupus × C. lycaon or C. lycaon × C. lupus ), and Gray Wolf ( C. lupus ). The implications for wolf recovery in the northeastern United States is discussed.

Abstract: I directly observed Coywolves ( Canis latrans × lycaon ; also called Eastern Coyote) successfully crossing over rivers/bays by traveling on paved (i.e., used by vehicles) bridges within their established territories. These data confirm that Coyotes/Coywolves use these narrow corridors in their travels, such as when colonizing new areas. I also report on breeding female, sick, and old Coywolves using human structures, including under overturned boats/canoes, under houses, and under sheds/decks. Breeding females ( n = 3) used these sites as dens, and sick ( n = 2) and old ( n = 2) individuals used them for shelter.

Abstract: Way et al. (2010) defi ne a "coywolf" population in the northeastern United States and eastern Canada that originated through hybridization between Canis lycaon (Eastern Wolf) and Canis latrans (Coyote), but they maintain that it is now genetically uniform and only minimally infl uenced by either parental spe- cies. An alternative interpretation of available data is that this northeastern Coyote population is genetically diverse, substantially more Coyote than Eastern Wolf in its genetic composition, and part of a larger population of Coyotes that interbreeds with a hybrid Coyote/Eastern Wolf population in southern Ontario and western Coyotes in western New York and Pennsylvania.

Abstract: We report on an eastern coyote or coywolf (Canis latrans × lycaon) pack in a heavily urbanized area at the northern edge of Boston, Massachusetts, living at a high pack density. We radio-collared four members of this social unit, a breeding pair and two of their juvenile offspring and tracked them from May 2004–Apr. 2005. The pack had a small cumulative territory area (overall = 2.05 km2), yet lived at a normal group size (fall = 6–7, winter = 4) for coyotes/coywolves in eastern North America. Fall density for this pack was 2.92–3.41/km2 and winter density was 1.95/km2, representing the highest recorded density for coyotes in this region.