Influence of hybridization on animal space use: A case study using coyote range expansion

Background/Question/Methods

Hybridization between animal species is likely to increase as distributional and reproductive barriers continue to break down due to anthropogenically-driven habitat and climate changes, yet the role that hybridization might play in shaping future space use patterns is understudied. Animal space use is a complex interaction between intrinsic factors, which hybridization can influence, and extrinsic factors, such as environmental heterogeneity. We sought to assess the relative contributions of intrinsic and extrinsic factors in driving space use in the C. latrans complex. Using home range size as a space use metric, we predicted that in regions where coyotes have hybridized extensively with wolves or dogs (eastern North America), home range size would be larger than where hybridization has not occurred, and that such intrinsic factors would supersede any effects of extrinsic factors such as habitat quality and prey availability. We conducted a meta-regression analysis of 67 datasets on coyote home range size across North America and generated models to predict coyote home range size. To identify the role of individual predictor variables in determining coyote home range size, we conducted weighted model averaging and ranked predictor variables using relative importance values.

Results/Conclusions

In general, coyote home range size was larger and more variable in populations with hybridization (hybrid: mean = 39.5 ± 1.3 km² (SE); non-hybrid: mean = 22.0 ± 0.6 km²) and the proportion of forest cover was generally higher where hybrid coyotes occurred (hybrid: mean = 0.75 ± 0.05; non-hybrid: mean = 0.66 ± 0.03). Hybridization was the most important predictor of coyote home range size (mean Σ = 0.99). Forest cover, though often cited as an alternative driver of the differences in home range size observed between hybridized and non-hybridized coyotes, was not an important predictor of coyote home range size (mean Σ = 0.22). We found that hybridization increased average coyote home range size by >20 km². Hybridization with wolves or dogs has likely allowed coyotes to develop resource needs and resource acquiring behaviors that are more wolf- or dog-like and thus require more space. Our findings add to the growing body of literature supporting eastern coyotes as ecologically distinct from western coyotes. More importantly, however, our findings demonstrate that hybridization can have a more important impact on how animals use space across large spatial scales than environmental variability.