Walking the line: Investigating biophysical characteristics related to wildlife use of linear features

Abstract

Habitat restoration is a necessary component of wildlife conservation in anthropogenic landscapes. To ensure restoration initiatives achieve the desired effects on wildlife communities, it is useful to investigate how animals use landscape features. Understanding the relationships between wildlife use and ecological cues provides specific and measurable targets that can be used to measure restoration success. In western Canada, linear feature networks formed by seismic lines, pipelines and roads have altered the boreal forest landscape and resulted in population declines for woodland caribou. Restoration is aimed at supporting caribou recovery by deterring linear feature use by caribou predators and ungulate competitors. Information on how linear feature characteristics facilitate or deter wildlife use supports restoration initiatives by providing specific targets for restoration. Here, we used wildlife track and sign data to investigate biophysical characteristics related to the use of linear features by canines, bears, deer, elk and moose in caribou ranges of west‐central and north‐western Alberta and British Columbia. We built generalized linear mixed models consistent with three hypotheses that could explain likely mechanisms for use: (1) ease of movement, (2) risk avoidance and (3) resource availability (prey and forage). Moose, deer, elk and bears were more likely to use linear features with either human or game trails. Bears and canines were less likely to use seismic lines with greater lateral vegetation cover and taller vegetation, respectively. Moose, deer and elk were more likely to use linear features with a greater cover of ungulate forage taxa such as willow, birch, sedges and forbs. These results suggest that restoration focusing on trails, online vegetation structure and online vegetation type should deter predators and ungulate prey species to the overall benefit of caribou. Our study corroborates the findings of other research recommending structural and functional restoration using high‐intensity line blocking and vegetative regeneration. We provide specific targets for linear feature restoration to assist in prioritization according to restoration objectives, which translates to a broader goal of linking local‐level restoration actions to landscape‐level conservation goals. This approach to restoration has implications for any major system experiencing anthropogenic landscape change.

Whose line is it anyway? Moose (Alces alces) response to linear features

“…These results suggest that during winter, in particular, there are characteristics of the seismic lines themselves that make them attractive to moose rather than moose selection of seismic lines being driven by a paucity of alternate travel routes (other linear features) or early seral forage (harvest blocks, wildfires). In comparison to wider and maintained linear features like roads and pipelines, it is possible that seismic lines are attractive to moose during winter because they provide a combination of forage, travel routes, shelter (thermal, snow interception), and security (proximity to mature forest) (Finnegan, MacNearney, et al, 2018; Kunkel & Pletscher, 2000; Tattersall et al, 2023; van Beest et al, 2012). Although roads and pipelines also provide forage and travel routes, forage is predominately at the edge of those features (MacDonald et al, 2020; Roever et al, 2008), and because roads and pipelines are wider than seismic lines, they likely have less thermal shelter, and lower snow interception.…”

“…During summer, the width of pipelines combined with ongoing vegetation management may result in pipelines having similar thermal cover, but less forage availability than harvest blocks and wildfires, making pipelines less attractive to moose when harvest blocks and wildfires are available. Moose use of harvest blocks and pipelines during summer is linked to the availability of shrubs and lateral cover (McKay & Finnegan, 2023;Tattersall et al, 2023); pipelines are periodically cleared to maintain line-of-sight (Alberta Energy Regulator, 2016;MacDonald et al, 2020), while with the exception of mechanical or chemical stand tending a few years after planting, harvest blocks are left to regenerate. Therefore, harvest blocks and areas that are naturally regenerating after wildfires are likely more attractive sources of shrub and sapling moose forage than maintained pipelines with graminoids and clover less preferred by moose (MacDonald et al, 2020;McKay & Finnegan, 2023;Tattersall et al, 2023).…”

“…Moose use of harvest blocks and pipelines during summer is linked to the availability of shrubs and lateral cover (McKay & Finnegan, 2023;Tattersall et al, 2023); pipelines are periodically cleared to maintain line-of-sight (Alberta Energy Regulator, 2016;MacDonald et al, 2020), while with the exception of mechanical or chemical stand tending a few years after planting, harvest blocks are left to regenerate. Therefore, harvest blocks and areas that are naturally regenerating after wildfires are likely more attractive sources of shrub and sapling moose forage than maintained pipelines with graminoids and clover less preferred by moose (MacDonald et al, 2020;McKay & Finnegan, 2023;Tattersall et al, 2023). During winter, as previously mentioned, pipelines likely offer less shelter, cover, and forage available above the snowpack than seismic lines, which is likely driving winter moose selection for pipelines only when other linear features are not available to them.…”

“…Finally, the fix rate of the moose GPS data we used in this study meant that we were only able to assess links between linear feature characteristics and moose habitat selection as a function of distance to linear features, rather than when moose were on linear features. Future work using more frequent GPS fix rates (Dickie et al, 2020;Dickie, Serrouya, DeMars, et al, 2017) (although using 15-min fix rates, only ~1% of steps were on linear features; Dickie et al, 2020), or that assess moose use of linear features using cameras or tracks and signs (Dickie et al, 2023;Tattersall et al, 2020Tattersall et al, , 2023, will likely provide more detailed information on the links between fine-scale linear feature characteristics and moose use of linear features.…”

“…Linear features also facilitate predator movement (Dickie, Serrouya, McNay, et al, 2017; Finnegan, Pigeon, et al, 2018), so disturbance increases overlap between caribou and predators, decreasing caribou survival (Mumma et al, 2017, 2018; Wittmer et al, 2005). Although the geographic footprint of linear features means that in comparison with polygonal disturbances, their contribution to the numerical response of moose is likely minimal, we know that moose use linear features to access forage and/or for movement (St‐Pierre et al, 2022; Tattersall et al, 2023), and we know wolves follow their prey (Gasway et al, 1989). Correspondingly, caribou are at increased predation risk where they co‐occur with moose (James et al, 2004; Peters et al, 2013) and when they are close to linear features (McKay et al, 2021; Mumma et al, 2017).…”