Limitations of current knowledge about the ecology of Grey Foxes hamper conservation efforts

Abstract

Species-specific conservation is important for maintaining the integrity of ecological communities but is dependent on sufficiently understanding multiple aspects of a species’ ecology. Species-specific data are commonly lacking for species in geographic areas with little research and species perceived to have insufficient charisma or economic importance. Despite their widespread distribution across central and North America and status as a furbearing mammal, little is known about the ecology of Grey Foxes Urocyon cinereoargenteus compared to other species of furbearing mammals. To understand what is known about this species, especially factors affecting population dynamics, we performed a systematic review of the scientific literature. We found 234 studies about Grey Foxes, with studies increasing substantially over time but with geographic gaps in the Great Plains and most of Mexico and central America. Most studies we reviewed examined relative abundance or occupancy (n= 35), habitat associations (n= 30), primarily as part of larger mammalian community studies, or spatiotemporal effects of other mammalian carnivores (n= 19), predominately Coyote Canis latrans. Grey Foxes were primarily forest-associated although associations with specific forest communities or anthropogenically disturbed habitats varied among studies. Multiple studies across ecoregions reported this fox as among both the most- and least-abundant mammalian carnivore. The inter-specific effects of Coyote were often, but not exclusively, negative and were likely mediated by landscape composition and human development. Importantly, very few studies examined population-effects of coyotes on Grey Foxes. Studies of population trends, demographics, and space use of Grey Foxes were comparatively rare and small inter- and intra-study sample sizes limited our ability to infer broader patterns. We suggest multiple avenues for future research to better understand the population status of this species throughout their range.

Modelling the distribution and intraguild associations of an understudied mesocarnivore across the contiguous United States

“…Grey foxes are often thought of as a forest dependent species (Allen et al, 2021;Borchert, 2012;Davis et al, 2011;Harmsen et al, 2019), and while forest covariates were important in our results, their effects were nuanced. ψ was positively affected by mixed deciduous forest edge at the 100 m scale and total forest edge at the 1 km scale.…”

“…Deciduous, mixed forest, and total forest cover The total size of each of wet forest, deciduous forest, and mixed forest, from Homer et al (2020) Grey foxes are often associated with various forest habitats (Allen et al, 2021;Borchert, 2012;Davis et al, 2011;Harmsen et al, 2019) p Deciduous, mixed forest, and total forest edge…”

“…Grey foxes (Urocyon cinereoargenteus) are a low-density and widespread but understudied mesocarnivore (Allen et al, 2021).…”

“…Effectively addressing this challenge is critical given the decline of many carnivore species and the shifting community dynamics among carnivore guilds due to apex carnivore losses and associated trophic downgrading (Estes et al, 2011; Prugh et al, 2009; Ripple et al, 2014). Despite recent increased research effort to address this challenge for several large carnivore species (e.g., wolves Canis lupus and pumas Puma concolor ; Ripple et al, 2014), there remain substantial knowledge gaps for many species, especially cryptic and low‐density mesocarnivores (Allen et al, 2021; Moll et al, 2016).…”

“…Grey foxes ( Urocyon cinereoargenteus ) are a low‐density and widespread but understudied mesocarnivore (Allen et al, 2021). Grey foxes are an adaptable species, being found in many temperate and tropical habitats, and ranging from Canada south into Central America.…”