Variable effects of snow conditions across boreal mesocarnivore species

Abstract

This is an author-produced, peer-reviewed version of this article. The final, definitive version of this document can be found online at AbstractMesocarnivores are increasingly recognized as key drivers of community dynamics, but the effects of bottom-up and abiotic factors on mesocarnivore populations remain poorly understood. We evaluated the effects of snow conditions, prey abundance, and habitat type on the distribution of five sympatric mesocarnivore species in interior Alaska using repeated snow track surveys and occupancy modelling. Snow depth and snow compaction were the best predictors of mesocarnivore occupancy, with differential effects across species. Coyotes (Canis latrans (Say, 1823)) and red foxes (Vulpes vulpes L., 1758) occurred in areas of shallow, compact snow, Canada lynx (Lynx canadensis (Kerr, 1792)) occurred in areas of shallow, fluffy snow, and wolverines (Gulo gulo L., 1758) and marten (Martes americana (Turton, 1806)) occurred in areas of deep, fluffy snow. These findings indicate that altered snow conditions due to climate change may have strong direct effects on the distribution of northern mesocarnivores, with divergent effects across species.

Navigating snowscapes: scale‐dependent responses of mountain sheep to snowpack properties

“…Conditions such as deep snow or icing caused by rain-on-snow events (Stien et al 2010) can severely limit the ability of herbivores to access ground forage, decrease efficiency of movement (Parker et al 1984), and increase predation risk (Hebblewhite et al 2005, Sand et al 2006, Brodie et al 2014, Lendrum et al 2017. Thus, the snow-covered period is often limiting for terrestrial mammals living in temperate and Arctic regions (Parker et al 2009), with strong selective forces linking environmental conditions, animal behavior, and fitness (Boutin and Lane 2014 Snowscapes may have especially strong effects on wildlife in Arctic and boreal ecosystems where snow cover persists for much of the year (Callaghan et al 2011a, Pozzanghera et al 2016). The Arctic is warming at twice the rate of lower latitudes and is predicted to experience elevated levels of precipitation with a higher proportion falling as rain (Olsen et al 2011, Bintanja and Selten 2014, Bring et al 2016, Vihma et al 2016.…”

Boreal predator co‐occurrences reveal shared use of seismic lines in a working landscape

“…Specifically, we predicted that (1) if black bears, lynx, and coyotes experience top‐down pressures from wolves, they should spatiotemporally segregate from wolves; (2) subordinate predators should segregate from their intraguild competitors with whom they share resources (O'Donoghue et al, ; Guillaumet, Bowman, Thornton, & Murray, ); and (3) subordinate predators should overlap with their prey (Keim, DeWitt, & Lele, ; Theuerkauf, ). We further hypothesized that higher densities of disturbance would result in lower occurrences of black bears, but higher occurrences of lynx and coyotes (Fisher & Burton, ), and that coyotes and lynx would occur less frequently in the winter (Pozzanghera, Sivy, Lindberg, & Prugh, ).…”

Potential influence of high‐elevation wind farms on carnivore mobility

“…Mammalian carnivores greatly influence lower trophic levels (Crooks and Soulé , Sergio et al ) yet respond differentially to climate and environment (Pozzanghera et al ), and habitat loss and fragmentation (Crooks ). Those living in northern latitudes are sensitive to changes in snowpack and include habitat specialists and generalists (Dowd et al , Pozzanghera et al ). For example, Canada lynx ( Lynx canadensis ) are adapted for deep snow and primarily inhabit boreal forest (Murray et al , Hoving et al ).…”

“…Generalist carnivores, however, like bobcats ( Lynx rufus ) are negatively affected by deep snow, inhabit a diversity of habitats, and are better competitors than specialists (Peers et al , Reed et al ). Because of their important ecosystem roles and variable response to abiotic and biotic factors, carnivores are ideal study organisms to evaluate the effects of climate and disturbance on terrestrial wildlife communities (Crooks , Sergio et al , Pozzanghera et al ).…”

“…However, these relationships are less pronounced during mild winters (Meia and Weber , Crête and Larivière , Kolbe et al ). An understanding of these mechanisms is limited for a community of carnivores (although see recent findings by Pozzanghera et al ) yet is critical for understanding effective conservation to minimize conditions that compromise snow‐adapted species. In addition, climate change is predicted to decrease snowpack duration (Ning and Bradley ) and depth (Notaro et al ) in the northeastern United States, ultimately reducing population viability for boreal species such as martens and lynx (Carroll ).…”