Footload influences wildlife use of compacted trails in the snow

Abstract

Animals moving across snow surfaces sink to varying depths, increasing the energetic cost of travel. For ease of movement, animals may follow compacted trails created by sports such as snowmobiling and snowshoeing. We tested the assumption that animals less‐adapted to snow travel (i.e. animals with a high footload (body mass/foot surface area)) are more likely to use compacted trails and follow them for greater distances than animals well‐adapted to moving on snow. We sampled animal movements on compacted and non‐compacted transects in northwestern Wyoming and southeastern Idaho, USA, during two winters. Consistent with our prediction, footload positively influenced the probability of animals following compacted transects, and positively influenced their following distance, although the latter relationship was weaker. Additionally, we found that different snow sports cause similar increases in snow density. We suggest that future researchers experimentally test whether the use of compacted trails by animals with high footloads alters their habitat selection and dispersal, and whether it affects their competitive and predatory success.

Terrestrial locomotion of the Svalbard rock ptarmigan: comparing field and laboratory treadmill studies

“…Conversely, we found the birds used aerial running gaits exclusively on firmer snow suggesting that the bouncing mechanism, linked to elastic energy recovery during the stance phase when running 54,55 , only functions when moving over firm ground. Other animals, for example many mesopredators, in snowy conditions also demonstrate a preference for moving over shallow compressed snow either to minimize energy expenditure 23–27 or simply to travel faster 26 . A softer substrate would absorb some or (all) of the kinetic and potential energy during the stance phase reducing the elastic energy available for the next stride 55 .…”

Habitat, Climate, and Fisher and Marten Distributions

“…In addition to logging, climate change that affects forest fire regimes is expected to result in the loss of late-successional vegetation, which may increase the probability of extirpation of associated species, such as fisher and marten (Bergeron et al 2010, Lawler et al 2012, Purcell et al 2012. Changes in winter conditions should facilitate the movement of fishers and other mesocarnivores, and may change the partitioning of niches based upon snow characteristics (Whiteman andBuskirk 2013, Manlick et al 2017). Indeed, many medium-sized predators have already expanded their ranges, which can affect food webs and trophic controls (Prugh et al 2009, Pokallus andPauli 2015).…”

The emergence of “fat bikes” in the USA: Trends, potential consequences and management implications

“…For example, in some mountain ecosystems large scale maintenance of ski pistes results in compaction of snow and reductions in the habitability of the subnivean space (space between snow surface and the ground) critical to the overwintering of small mammals (Sanecki, Green, Wood, & Lindenmayer, 2006;Negro, Isaia, Palestrini & Rolando, 2009;Sato, Wood, & Lindenmayer, 2013). Snow compacted attract animals with high footloads (body mass per foot surface area) due to ease of travel, but it is unclear if this influences habitat selection and dispersal (Whiteman & Buskirk, 2013). Further, snow compaction may contribute to trail widening over time if spring trail users avoid the persistent snow and travel on trailside areas.…”