Integration of aerial surveys and resource selection analysis indicates human land use supports boreal deer expansion

Abstract

Landscape change is a driver of global biodiversity loss. In the western Nearctic, petroleum exploration and extraction is a major contributor to landscape change, with concomitant effects on large mammal populations. One of those effects is the continued expansion of invasive white‐tailed deer populations into the boreal forest, with ramifications for the whole ecosystem. We explored deer resource selection within the oil sands region of the boreal forest using a novel application of aerial ungulate survey (AUS) data. Deer locations from AUS were “used” points and together with randomly allocated “available” points informed deer resource selection in relation to landscape variables in the boreal forest. We created a candidate set of generalized linear models representing competing hypotheses about the role of natural landscape features, forest harvesting, cultivation, roads, and petroleum features. We ranked these in an information‐theoretic framework. A combination of natural and anthropogenic landscape features best explained deer resource selection. Deer strongly selected seismic lines and other linear features associated with petroleum exploration and extraction, likely as movement corridors and resource subsidies. Forest harvesting and cultivation, important contributors to expansion in other parts of the white‐tailed deer range, were not as important here. Stemming deer expansion to conserve native ungulates and maintain key predator–prey processes will likely require landscape management to restore the widespread linear features crossing the vast oil sands region.

Logging, linear features, and human infrastructure shape the spatial dynamics of wolf predation on an ungulate neonate

“…The combined effects of climate change and human disturbance have facilitated the northward range expansion of white‐tailed deer into boreal forest ecosystems (Dawe & Boutin, 2016; Frelich et al, 2012; Fuller et al, 2023). At the same time, moose abundance and distribution have retracted at their southern edge, while wolf populations have steadily recovered and extended their range southward in Minnesota (Minnesota Department of Natural Resources, 2022) and elsewhere along the temperate forest–boreal forest ecotone (Bowman et al, 2010; Frelich et al, 2012).…”

“…As the range of overlap between white‐tailed deer and wolves expands, understanding wolf predation on deer will become increasingly important. This is particularly true for areas where deer expansion may alter boreal food webs through negative indirect effects on ungulates such as moose and caribou (Fuller et al, 2023), including intensifying predation on other ungulates through apparent competition (Latham et al, 2013; Latham, Latham, McCutchen, & Boutin, 2011). If anthropogenic linear features increase the efficiency with which wolves hunt deer, as our results suggest, the indirect effects of deer expansion on other ungulates will be exacerbated by human activity via mechanisms such as apparent competition.…”

“…(Alverson et al, 1988; Courtois et al, 2002; Litvaitis, 2001). Moose and deer density have increased in many systems due to the greater forage supply from timber harvesting and climate change (Dawe & Boutin, 2016; Frelich et al, 2012; Fuller et al, 2023; Laurent et al, 2021; Street et al, 2015), leading to apparent competition with the rarer endemic woodland caribou ( Rangifer tarandus caribou ) by subsidizing predators like wolves (Frenette et al, 2020; Latham et al, 2013; Serrouya et al, 2021). The combined effects of development and resource extraction practices have thus greatly altered local predator–prey dynamics (Boucher et al, 2022; Courbin et al, 2014; DeMars & Boutin, 2018; McKay et al, 2021; McKay & Finnegan, 2022; Whittington et al, 2011).…”

Habitat alteration or climate: What drives the densities of an invading ungulate?

“…Generally, this productivity gradient occurs along a northwest–southeast axis. Though agriculture is rare in the Boreal Plains and Boreal Shield, land clearing for oil and gas exploration and forest harvest are hypothesized to increase forage availability beyond the baseline variation in productivity (Serrouya et al., 2021), potentially supporting higher densities of deer (Fuller et al., 2022). However, concomitant with changes in habitat alteration, climate change has resulted in less severe winters that increase white‐tailed deer survival, and longer growing seasons that increases food availability (Beier & McCullough, 1990; Dawe & Boutin, 2016; Kennedy‐Slaney et al., 2018).…”

“…Generally, this productivity gradient occurs along a northwest-southeast axis. Though agriculture is rare in the Boreal Plains and Boreal Shield, land clearing for oil and gas exploration and forest harvest are hypothesized to increase forage availability beyond the baseline variation in productivity (Serrouya et al, 2021), potentially supporting higher densities of deer (Fuller et al, 2022).…”