1. While many studies have looked at how large mammals respond to road mitigation measures, few have examined the effects on smaller mammals. 2. We investigated the effectiveness of three different types of wildlife passages along Highway 175 in Quebec, Canada, for small-and medium-sized mammals (<30 kg) using infrared cameras. Wildlife passages (n = 17) were monitored 24 h a day 7 days a week from 2012 to 2015. Two research questions were addressed: (i) What influences passage discovery and use? and (ii) does it differ between species? Global and species-specific models were produced for both discovery and use. A linear mixed-effects model was used for the discovery data (log-transformed counts), and a generalized linear mixed model was used for the crossing data (binary response). 3. Species' responded to the passages differently, with discoveries increasing overall and in particular for marmots Marmota monax as latitude increased. Pipe culverts were significantly more likely to be discovered by micromammals and wooden ledge culverts by red squirrels Tamiasciurus hudsonicus. Older passages were discovered less in general, with the exception of marmots. Marmots were also the only species to show a difference in crossings by passage type, favouring pipe culverts. Passage use was less likely with a median present for all models, except squirrels. More open passages had higher use overall and particularly for marmots and weasels Mustela spp. 4. Synthesis and applications. By separating animal responses to wildlife passages into two types (discovery and use), we have shown it is possible to incorporate multiple dimensions into post-mitigation evaluation. This study highlights how transportation agencies can engineer more effective wildlife passages by minimizing the barrier effect of the structures themselves and constructing more passages better suited to the needs of the species they are targeting. To benefit the most species, it is recommended that future projects contain a diversity of open, single segment passages requiring long-term monitoring.

Scavenging by vertebrates can have important impacts on food web stability and persistence, and can alter the distribution of nutrients throughout the landscape. However, scavenging communities have been understudied in most regions around the globe, and we lack understanding of the biotic drivers of vertebrate scavenging dynamics. In this paper, we examined how changes in prey density and carrion biomass caused by population cycles of a primary prey species, the snowshoe hare Lepus americanus, influence scavenging communities in the northern boreal forest. We further examined the impact of habitat and temperature on scavenging dynamics. We monitored the persistence time, time until first scavenger, and number of species scavenging experimentally‐placed hare carcasses over four consecutive years in the southwestern Yukon. We simultaneously monitored hare density and carrion biomass to examine their influence relative to temperature, habitat, and seasonal effects. For the primary scavengers, we developed species‐specific scavenging models to determine variation on the effects of these factors across species, and determine which species may be driving temporal patterns in the entire community. We found that the efficiency of the scavenging community was affected by hare density, with carcass persistence decreasing when snowshoe hare densities declined, mainly due to increased scavenging rates by Canada lynx Lynx canadensis. However, prey density did not influence the number of species scavenging a given carcass, suggesting prey abundance affects carrion recycling but not necessarily the number of connections in the food web. In addition, scavenging rates increased in warmer temperatures, and there were strong seasonal effects on the richness of the vertebrate scavenging community. Our results demonstrate that vertebrate scavenging communities are sensitive to changes in species’ demography and environmental change, and that future assessments of food web dynamics should consider links established through scavenging.

Individual natal dispersal behaviour is often difficult to predict as it can be influenced by multiple extrinsic and intrinsic factors. Individual differences in personality have been shown to be an important correlate of dispersal behaviour. However, the relationships between personality traits and dispersal are often inconsistent within and across studies and the causes of these discrepancies are often unknown. Here we sought to determine how individual differences in activity and aggression, as measured in an open-field trial, were related to natal dispersal distance in a wild population of North American red squirrels (Tamiasciurus hudsonicus). For 14 cohorts, while individual aggression consistently had no association with dispersal distance, the association between activity and dispersal fluctuated through time, mediated by population density. The environmental-dependence of the relationship between personality and dispersal in this population is indicative of the importance of considering external conditions when predicting dispersal behaviour.

Dispersal is nearly universal; yet, which sex tends to disperse more and their success thereafter depends on the fitness consequences of dispersal. We asked if lifetime fitness differed between residents and immigrants (successful between-population dispersers) and their offspring using 29 years of monitoring from North American red squirrels (Tamiasciurus hudsonicus) in Canada. Compared to residents, immigrant females had 23% lower lifetime breeding success (LBS), while immigrant males had 29% higher LBS. Male immigration and female residency were favoured. Offspring born to immigrants had 15-43% lower LBS than offspring born to residents. We conclude that immigration benefitted males, but not females, which appeared to be making the best of a bad lot. Our results are in line with male-biased dispersal being driven by local mate competition and local resource enhancement, while the intergenerational cost to immigration is a new complication in explaining the drivers of sex-biased dispersal.

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