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We developed and validated a density-adjusted spatial model to predict moose (Alces alces) highway-crossing probability to see if the model could be used as an index of moose-vehicle collision risk. We installed Global Positioning System telemetry collars on 47 moose in the north of the Laurentides Wildlife Reserve, Québec, for 2-36 months. We recorded only 84 highway crossings in spring (0.29% of 28,967 2-hr steps) and 122 crossings in summer (0.18% of 68,337 2-hr steps), despite a high sampling effort and having captured moose close to highways. Moose movement rates during movement steps crossing a highway were on average 3 times higher than during the steps preceding or following highway crossing. Paths used by moose when crossing a highway were characterized by a high proportion of food stands, low proportion of lakes and rivers, and topography typical of a valley. Highway-crossing sites were located in valleys with brackish pools and forest stands providing coniferous cover but a low proportion of lakes and rivers. We adjusted moose crossing probability for local variation in moose density using aerial survey data and assessed crossing probability along the highways in the entire Laurentides Wildlife Reserve. We tested the model using moose-vehicle accident data from 1990 to 2002. The relationship between the density-adjusted crossing probability and number of accidents was relatively loose at the 1-km scale but improved markedly when using longer highway sections (5-15 km; r > 0.80). Our results demonstrate that roads and their surroundings are perceived as low-quality habitat by moose. We also conclude that road segments installed along secondary valleys could be a highly strategic site to deploy mitigation measures such as fences and that it could be desirable to increase the width of road shoulders to reduce forest cover and to eliminate brackish pools to reduce cervid-vehicle collisions. We suggest using empirical data such as location of vehicle-wildlife collisions to plan mitigation measures at a fine scale. [ABSTRACT FROM AUTHOR]

Roads often negatively affect terrestrial wildlife, via habitat loss or fragmentation, noise, and direct mortality. We studied moose (Alces alces) behavior relative to a road network, in an area with a history of moose-vehicle accidents, to determine when moose were crossing roadways or using areas near roads and to investigate if environmental factors were involved in this behavior. We tracked 47 adult moose with Global Positioning System collars in a study area crossed by highways and forest roads. We hypothesized that moose would avoid crossing roads but would make occasional visits to roadsides to feed on sodium-rich vegetation and avoid biting insects. Further, we expected moose avoidance to be greater for highways than forest roads. We recorded 196,710 movement segments but only observed 328 highway and 1,172 forest-road crossings (16 and 10 times lower than expected by chance). Moose usually avoided road proximity up to ≥500 m on each side but 20% of collared moose made visits to areas within 50 m of highways, which might have resulted from moose searching for sodium in vegetation and roadside salt pools. In fact, vegetation along highways had higher sodium concentrations and was browsed in similar proportions to vegetation in adjacent forest, despite moose avoidance of these zones. Moose, however, did not use areas near roads more during periods of biting insect abundance. Our results supported the hypothesis of scale-dependent selection by moose; avoidance of highways at a coarse scale may confer long-term benefits, whereas selection of highway corridors at finer scales may be part of a strategy to overcome short-term limiting factors such as sodium deficiency. We found a positive relationship between home-range size and the proportion of road axes they contained, suggesting that moose either compensated for habitat loss or made specific movements along highways to gather sodium. The presence of sodium along highways likely increases moose-vehicle accident risks. Removal of salt pools or use of a de-icing salt other than sodium chloride should render highway surroundings less attractive to moose. [ABSTRACT FROM AUTHOR]

Sodium has many fundamental physiological functions in animals but is rare in boreal ecosystems where moose (Alces alces) thrive. In Québec (Canada), sodium is readily available in aquatic vegetation and in salt pools that form along highways. We do not know if moose are adopting specific behaviors to access sodium sources or if they simply use the sodium sources they encounter during their movements. We tested the hypothesis that moose modify both space and habitat use to gather sodium from salt pools. We expected moose to use salt pools mostly in spring and early summer, when needs are greatest and before aquatic vegetation has fully developed. We fitted 47 moose with Global Positioning System telemetry collars and collected data for 2 to 36 months between 2003 and 2006. We rarely located moose at salt pools (0.12% among the 95,007 locations collected). As we expected, use of salt pools was highest in late spring and in early summer, and we observed a time lag between peak use of salt pools compared to use of lakes and waterways, indicating moose fulfilled their sodium requirements in salt pools before aquatic vegetation was available. Moose selected salt pools over lakes and waterways when these 2 sodium sources were present in their home range and moved rapidly over large distances to reach them. Our results were consistent with moose using salt pools when they are likely to be sodium deficient. Salt pools were less accessible, required long-distance movements, and were located in habitually avoided areas along highways. Elimination of roadside salt pools should be considered among strategies to reduce cervid-vehicle collision risks in boreal environments. [ABSTRACT FROM AUTHOR]

Wildlife-vehicle collisions cause numerous human fatalities and injuries, and generate considerable expenses in property damage each year. Certain characteristics of the road and its surroundings are known to have an impact on collision probability. Roadside salt pools increase the risk of collision by attracting moose (Alces alces) to the side of the road. In the Laurentides Wildlife Reserve of Québec, Canada, roadside salt pools were drained and filled with rocks to deter moose from drinking. We surveyed 12 roadside salt pools during 3 consecutive summers (2003-2005) from mid-May to mid-August. Seven salt pools were managed in autumn 2004, and 5 pools were left untreated. We equipped all 12 sites with electronic apparatus that allowed us to detect moose attendance and study their behavior. We also measured physical, chemical, and environmental characteristics of these pools and other unvisited pools in order to correlate moose attendance with specific habitat criteria. We found that moose mostly attended roadside salt pools from mid-June to mid-July, with a decrease in August. Moose attendance was significantly correlated with visual obstruction toward the road and water availability. Management of the pools caused a decrease in mean length of time moose spent at them. Number of visits decreased significantly at night (by 90%), which was when most visits occurred, but not during the day. The proposed management practice prevented all visiting moose from drinking brackish water. These results suggest that moose should eventually lose interest in treated salt pools, therefore decreasing the risk of moose-vehicle collisions on the road. [ABSTRACT FROM AUTHOR]

We tested the effectiveness of electric fences to reduce moose (Alces alces)-vehicle collisions in 2 fenced sectors (5 km and 10 km) using weekly track surveys and Global Positioning System telemetry. Number of moose tracks along highways decreased by approximately 80% following fence installation. Only 30% (16/53) of moose tracks observed on the road side of the fence were left by moose that crossed an operational fence; moose mostly entered the fenced corridor through openings (e.g., secondary roads) or at fence extremities. Electric fences also prevented 78% (7/9) of collared moose from crossing the highway in fenced sectors. Fences were less effective during occasional power failures. We suggest that circuit breakers should be used to prevent power failures and that there should be no opening along the fence line unless antiungulate structures are used. [ABSTRACT FROM AUTHOR]

Between 1990 and 2002, more than 200 moose-vehicle collisions occurred each year in Quebec, including about 50/yr in the Laurentides Wildlife Reserve. One cause is the presence of roadside salt pools that attract moose near roads in the spring and summer. Using the computer simulation technique of agent-based modeling, this study investigated whether salt pool removal and displacement, i.e., a compensatory salt pool set up 100 to 1500 m away from the road shoulder, would reduce the number of moose-vehicle collisions. Moose road crossings were used as a proxy measure. A GPS telemetry data set consisting of approximately 200,000 locations of 47 moose over 2 yr in the Laurentides Wildlife Reserve was used as an empirical basis for the model. Twelve moose were selected from this data set and programmed in the model to forage and travel in the study area. Five parameters with an additional application of stochasticity were used to determine moose movement between forest polygons. These included food quality; cover quality, i.e., protection from predators and thermal stress; proximity to salt pools; proximity to water; and slope. There was a significant reduction in road crossings when either all or two thirds of the roadside salt pools were removed, with and/or without salt pool displacement. With 100% salt pool removal, the reduction was greater (49%) without compensatory salt pools than with them (18%). When two thirds of the salt pools were removed, the reduction was the same with and without compensatory salt pools (16%). Although moose-vehicle collisions are not a significant mortality factor for the moose population in the Laurentides Wildlife Reserve, in areas with higher road densities, hunting pressure, and/or predator densities it could mean the difference between a stable and a declining population, and salt pool removal could be part of a good mitigation plan to halt population declines. This model can be used, with improvements such as spatial memory of salt pool locations and the addition of a road avoidance behavior, to assess the effectiveness of mitigation measures intended to reduce moose-vehicle collisions. [ABSTRACT FROM AUTHOR]