Summary1. Within the rapidly developing field of movement ecology, much attention has been given to studying the movement of individuals within a subset of their population's occupied range. Our understanding of the effects of landscape heterogeneity on animal movement is still fairly limited as it requires studying the movement of multiple individuals across a variety of environmental conditions. Gaining deeper understanding of the environmental drivers of movement is a crucial component of predictive models of population spread and habitat selection and may help inform management and conservation. 2. In Ontario, woodland caribou (Rangifer tarandus caribou) occur along a wide geographical gradient ranging from the boreal forest to the Hudson Bay floodplains. We used highresolution GPS data, collected from 114 individuals across a 450 000 km 2 area in northern Ontario, to link movement behaviour to underlying local environmental variables associated with habitat permeability, predation risk and forage availability. 3. We show that a great deal of observed variability in movement patterns across space and time can be attributed to local environmental conditions, with residual individual differences that may reflect spatial population structure. 4. We discuss our results in the context of current knowledge of movement and caribou ecology and highlight potential applications of our approach to the study of wide-ranging animals.

A northern population of snapping turtles (Chelydra serpentina) centred around Lake Sasajewun in the Wildlife Research Area in Algonquin Park, Ontario, has been studied and individually marked since 1972. From 1972 to 1985, annual mortality and survivorship of adult females had been estimated at 1 and 96.6%, respectively, and only six dead turtles were found. Lake Sasajewun's population of C. serpentina was estimated in 1978–1979 and 1984–1985 at 38 and 47 adults, respectively. From 1976 to 1987, total number of nests found in the study area remained fairly constant and there were no significant changes in mean clutch size, mean clutch mass, or mean egg mass. On the main nest site, recruitment from 1976 to 1987 was 1.15 (1.8%) new females per year. From 1987 to 1989, we found 34 dead adult snapping turtles in the Wildlife Research Area. Observations of freshly dead animals indicated that most were killed by otters (Lutra canadensis) during the turtles' winter hibernation. A few uninjured turtles also died of septicemia in early spring shortly after emerging from hibernation. The estimated number of adults in Lake Sasajewun was 31 in 1988–1989, and the minimum number of adult residents known to be alive in the lake dropped from 47 in 1986 to 16 in 1989. In 1986 and 1987, annual adult female survivorship was estimated at 80 and 55%, respectively, and estimated numbers of nesting females declined from 82 in 1986 to 71 and 55 in 1987 and 1988, respectively. The actual number of nests found declined by 38 and 20% over the same periods. Although no significant differences occurred in mean egg mass or mean clutch size between 1987 and 1989 and earlier years, the mean clutch mass in 1988 was larger than in 1977 or 1978. This difference appeared to be due to a gradual increase in the mean age and body size of breeding females rather than to density-dependent changes. Recruitment into the adult breeding female population in 1987–1989 remained less than two individuals per year. Hatchling survival and number of juveniles were low throughout the study. Our observations support the view that populations of species with high, stochastic juvenile mortality and long adult life spans may be decimated quickly by increased mortality of adult animals, particularly if numbers of juveniles and immigrants are low. Recovery of such populations should be very slow because of a lack of effective density-dependent response in reproduction and recruitment.

Movement patterns offer a rich source of information on animal behaviour and the ecological significance of landscape attributes. This is especially useful for species occupying remote landscapes where direct behavioural observations are limited. In this study, we fit a mechanistic model of animal cognition and movement to GPS positional data of woodland caribou (Rangifer tarandus caribou; Gmelin 1788) collected over a wide range of ecological conditions. The model explicitly tracks individual animal informational state over space and time, with resulting parameter estimates that have direct cognitive and ecological meaning. Three biotic landscape attributes were hypothesized to motivate caribou movement: forage abundance (dietary digestible biomass), wolf (Canis lupus; Linnaeus, 1758) density and moose (Alces alces; Linnaeus, 1758) habitat. Wolves are the main predator of caribou in this system and moose are their primary prey. Resulting parameter estimates clearly indicated that forage abundance is an important driver of caribou movement patterns, with predator and moose avoidance often having a strong effect, but not for all individuals. From the cognitive perspective, our results support the notion that caribou rely on limited sensory inputs from their surroundings, as well as on long-term spatial memory, to make informed movement decisions. Our study demonstrates how sensory, memory and motion capacities may interact with ecological fitness covariates to influence movement decisions by free-ranging animals.

Monitoring of forest songbirds via auditory detections during point surveys can be enhanced by using preprogrammed recording devices. During May–July 2008, we compared boreal forest bird surveys conducted with SM‐1 bird song recorders (Wildlife Acoustics, Inc.) with field surveys by observers and surveys recorded with the E3A Bio‐Acoustic Monitor Kit (River Forks Research Corp.) in Ontario, Canada, to evaluate the utility of the SM‐1 to generate reliable detections of forest birds. The SM‐1 surveys identified, on average, 8.95 species, 0.76 fewer species per 10‐min point count than field surveys (${\bar {x}}$ = 9.71 species) and 1.26 fewer species than the E3A (${\bar {x}}$ = 10.21 species). SM‐1 surveys also identified on average 11.6 individuals per 10‐min count, 2.5 fewer than field surveys (${\bar {x}}$ = 14.1) and 2.3 fewer than E3A surveys (${\bar {x}}$ = 13.9), respectively. The lower number of SM‐1 detections, however, was less than the reduction in detections made by field surveys later as compared to earlier in the breeding season. This suggests that SM‐1 recorders set up early in the season would detect more birds than field surveys stretching late into the season. Moreover, lower detections with the SM‐1 could be easily offset by collecting an additional 10‐min sample on another day. Most species were detected equally well by all 3 methods with a few exceptions. Unattended recording devices are especially advantageous in situations where the number of experienced observers is limited, where access difficult, where multiple samples at the same site are desirable, and where it is desirable to eliminate inter‐observer, time‐of‐day and time‐of‐season effects. © 2011 The Wildlife Society.

Summary1. Although local variation in territorial predator density is often correlated with habitat quality, the causal mechanism underlying this frequently observed association is poorly understood and could stem from facultative adjustment in either group size or territory size. 2. To test between these alternative hypotheses, we used a novel statistical framework to construct a winter population-level utilization distribution for wolves (Canis lupus) in northern Ontario, which we then linked to a suite of environmental variables to determine factors influencing wolf space use. Next, we compared habitat quality metrics emerging from this analysis as well as an independent measure of prey abundance, with pack size and territory size to investigate which hypothesis was most supported by the data. 3. We show that wolf space use patterns were concentrated near deciduous, mixed deciduous/ coniferous and disturbed forest stands favoured by moose (Alces alces), the predominant prey species in the diet of wolves in northern Ontario, and in proximity to linear corridors, including shorelines and road networks remaining from commercial forestry activities. 4. We then demonstrate that landscape metrics of wolf habitat quality -projected wolf use, probability of moose occupancy and proportion of preferred land cover classes -were inversely related to territory size but unrelated to pack size. 5. These results suggest that wolves in boreal ecosystems alter territory size, but not pack size, in response to local variation in habitat quality. This could be an adaptive strategy to balance trade-offs between territorial defence costs and energetic gains due to resource acquisition. That pack size was not responsive to habitat quality suggests that variation in group size is influenced by other factors such as intraspecific competition between wolf packs.

Because variation in fat reserves (i.e., condition) is expected to contribute to variation in survival and reproductive success, zoologists often wish to estimate the condition of the animals they study. The conventional condition estimates used for snakes are the residuals from a regression of body mass on body length. Because this estimate of condition is not independent of the variables used to estimate it (i.e., fat is a component of body mass), estimates derived in this fashion will be confounded whenever fat varies nonrandomly with length. To avoid this problem we used total lipid extraction to estimate percent body fat in a representative sample of northern water snakes (Nerodia sipedon). The conventional condition index explained less than half the variance in the measured percent body fat in this sample. An improved estimate of condition calculated as the difference between total body mass and predicted lean mass (based on the results of the lipid extraction) explained 70% of the variation in percent body fat in the original sample of snakes. This improved estimate also revealed that condition declined with body size in a large sample of male water snakes measured in early spring over a 4-year period. This last result, coupled with theoretical expectations that condition will not vary randomly with body size in snakes, suggests that researchers interested in condition should derive indices from direct measurements of body fat.

We used more than 326 000 observations of temperature collected by radio telemetry from 38 individuals over three years to investigate thermoregulation and thermal relations of northern water snakes (Nerodia sipedon) near the northern limit of their distribution in Ontario, Canada. We tested hypotheses concerning the effects of feeding, season, sex, and reproductive condition on thermoregulation of individuals. The mean preferred body temperature (PBT) for captive snakes from the study population was 27.1ЊC, similar to that reported for other populations, and PBT range (defined as the 25th-75th percentiles of selected temperatures) was 25-30ЊC. When environmental conditions allowed, the mean and range of body temperature (T b ) of free-living snakes were nearly identical to those observed in captivity. The typical daily pattern in snake T b was an increase in late morning to a plateau temperature in the preferred range, followed by a decrease in the evening with a nightime plateau at approximately the temperature of the water. We calculated indices of thermoregulation to relate T b data to available ambient temperatures. Despite the northern latitude of the study population, ambient conditions were favorable over much of the activity season and offered the potential for the snakes to maintain T b within the PBT range almost 24 h per day for much of the season. However, the thermoregulation indices indicated that N. sipedon are only moderate thermoregulators, and often do not exploit opportunities to achieve PBT, particularly during the day. Variation in annual ambient temperatures affected growth rates of the snakes, and was sufficient to affect the age of maturity of females.Feeding did not elicit a thermophilic response under laboratory conditions or when snakes were fed experimentally in the field, suggesting that the benefits of increasing T b after eating did not outweigh the costs. Reproductive females thermoregulated more carefully than nonreproductive females during the July-August gestation period. Pregnant females may increase thermoregulatory behavior to enhance the rate and efficiency of embryogenesis. Males thermoregulated less than both reproductive and nonreproductive females, particularly later in the activity season when thermoregulation by females increased. We hypothesized that males pursue a survival strategy following the spring mating season and thus remain cool and secretive during the later part of the activity season. This strategy by males clearly contributes to their slowed growth and smaller size relative to females.

One of the most challenging tasks in wildlife conservation and management is to clarify how spatial variation in land cover due to anthropogenic disturbance influences wildlife demography and longterm viability. To evaluate this, we compared rates of survival and population growth by woodland caribou (Rangifer tarandus caribou) from 2 study sites in northern Ontario, Canada that differed in the degree of anthropogenic disturbance because of commercial logging and road development, resulting in differences in predation risk due to gray wolves (Canis lupus). We used an individual-based model for population viability analysis (PVA) that incorporated adaptive patterns of caribou movement in relation to predation risk and food availability to predict stochastic variation in rates of caribou survival. Field estimates of annual survival rates for adult female caribou in the unlogged (¯= x 0.90) and logged (¯= x 0.76) study sites recorded during 2010-2014 did not differ significantly (P > 0.05) from values predicted by the individual-based PVA model (unlogged:x = 0.87; logged:¯= x 0.79). Outcomes from the individual-based PVA model and a simpler stage-structured matrix model suggest that substantial differences in adult survival largely due to wolf predation are likely to lead to long-term decline of woodland caribou in the commercially logged landscape, whereas the unlogged landscape should be considerably more capable of sustaining caribou. Estimates of population growth rates (λ) for the 2010-2014 period differed little between the matrix model and the individual-based PVA model for the unlogged (matrix modelx = 1.01; individual-based modelx = 0.98) and logged landscape (matrix modelx = 0.88; individual-based modelx = 0.89). We applied the spatially explicit PVA model to assess the viability of woodland caribou across 14 woodland caribou ranges in Ontario. Outcomes of these simulations suggest that woodland caribou ranges that have experiencedThis is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. significant levels of commercial forestry activities in the past had annual growth rates <0.89, whereas caribou ranges that had not experienced commercial forestry operations had population growth rates >0.96. These differences were strongly related to regional variation in wolf densities. Our results suggest that increased wolf predation risk due to anthropogenic disturbance is of sufficient magnitude to cause appreciable risk of population decline in woodland caribou in Ontario.