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A \"landscape of fear\" (LOF) is a map that describes continuous spatial variation in an animal's perception of predation risk. The relief on this map reflects, for example, places that an animal avoids to minimize risk. Although the LOF concept is a potentially unifying theme in ecology that is often invoked to explain the ecological and conservation significance of fear, little is known about the daily dynamics of an LOF. Despite theory and data to the contrary, investigators often assume, implicitly or explicitly, that an LOF is a static consequence of a predator's mere presence within an ecosystem. We tested the prediction that an LOF in a large-scale, free-living system is a highly dynamic map with \"peaks\" and \"valleys\" that alternate across the diel (24-h) cycle in response to daily lulls in predator activity. We did so with extensive data from the case study of Yellowstone elk (Cervus elaphus) and wolves (Canis lupus) that was the original basis for the LOF concept. We quantified the elk LOF, defined here as spatial allocation of time away from risky places and times, across nearly 1,000-km² of northern Yellowstone National Park and found that it fluctuated with the crepuscular activity pattern of wolves, enabling elk to use risky places during wolf downtimes. This may help explain evidence that wolf predation risk has no effect on elk stress levels, body condition, pregnancy, or herbivory. The ability of free-living animals to adaptively allocate habitat use across periods of high and low predator activity within the diel cycle is an underappreciated aspect of animal behavior that helps explain why strong antipredator responses may trigger weak ecological effects, and why an LOF may have less conceptual and practical importance than direct killing.

To assess the susceptibility of elk (Cervus canadensis) and mule deer (Odocoileus hemionus) to SARS-CoV-2, we performed experimental infections in both species. Elk did not shed infectious virus but mounted low-level serologic responses. Mule deer shed and transmitted virus and mounted pronounced serologic responses and thus could play a role in SARS-CoV-2 epidemiology.

Context Conservation corridors must facilitate long-distance dispersal movements to promote gene flow, prevent inbreeding, and allow animals to shift ranges with climate change. Least-cost models are used to identify areas that support long-distance movement. These models rely on estimates of landscape resistance, which are typically derived from habitat suitability. Objectives We examine two key steps in estimating resistance from habitat suitability: choosing a procedure to estimate habitat suitability, and choosing a transformation function to translate habitat suitability into resistance. Methods We used linear and nonlinear functions to convert three types of habitat suitability estimates (from expert opinion, resource selection functions, and step selection functions) into resistances for elk ( Cervus canadensis ) and desert bighorn sheep ( Ovis canadensis nelsoni ). We evaluated the resulting resistance maps on an independent set of observed long-distance, prospecting movements. Results A negative exponential function best described the relationship between resistance values and habitat suitability for desert bighorn sheep indicating long-distance movers readily travel through moderately-suitable areas and avoid only the least suitable habitat. For desert bighorn sheep, all three suitability estimates performed better than chance, and resource and step selection functions outperformed expert opinion. For elk, all three suitability estimates performed the same as chance. Conclusions When designing corridors to facilitate long-distance movements of mobile animals, we recommend transforming habitat suitability into resistance with a negative exponential function. Use of an exponential transformation means that larger fractions of the landscape offer low resistance, allowing greater flexibility in where a corridor is located.

North American grasslands have experienced increased relative abundance of shrubs and trees over the last 150 yr. Alterations in herbivore composition, abundance, and grazing pressure along with changes in fire frequency are drivers that can regulate the transition from grassland to shrubland or woodland (a process known as woody encroachment). Historically, North American grasslands had a suite of large herbivores that grazed and/or browsed (i.e., bison, elk, pronghorn, deer), as well as frequent and intense fires. In the tallgrass prairie, many large native ungulates were extirpated by the 1860s, corresponding with increased homesteading (which led to decreased fire frequencies and intensities). Changes in the frequency and intensity of these two drivers (browsing and fire) have coincided with woody encroachment in tallgrass prairie. Within tallgrass prairie, woody encroachment can be categorized in to two groups: non-resprouting species that can be killed with fire and resprouting species that cannot be killed with fire. Resprouting species require additional active management strategies to decrease abundance and eventually be removed from the ecosystem. In this study, we investigated plant cover, ramet density, and physiological effects of continuous simulated browsing and prescribed fire on Cornus drummondii C.A. Mey, a resprouting clonal native shrub species. Browsing reduced C. drummondii canopy cover and increased grass cover. We also observed decreased ramet density, which allowed for more infilling of grasses. Photosynthetic rates between browsed and unbrowsed control shrubs did not increase in 2015 or 2016. In 2017, photosynthetic rates for browsed shrubs were higher in the unburned site than the unbrowsed control shrubs at the end of the growing season. Additionally, after the prescribed fire, browsed shrubs had ~90% decreased cover, ~50% reduced ramet density, and grass cover increased by ~80%. In the roots of browsed shrubs after the prescribed fire, nonstructural carbohydrates (NSC) experienced a twofold reduction in glucose and a threefold reduction in both sucrose and starch. The combined effects of browsing and fire show strong potential as a successful management tool to decrease the abundance of clonal-resprouting woody plants in mesic grasslands and illustrate the potential significance of browsers as a key driver in this ecosystem.

1. Roads are a prevalent, ever-increasing form of human disturbance on the landscape. In many places in western North America, energy development has brought human and road disturbance into seasonal winter range areas for migratory elk. 2. We sought to evaluate the predictions from the risk-disturbance hypothesis when studying elk response to roads during winter. Road proximity and crossing were used to evaluate these behaviours, which offered a rare comparison between two common measures of roads. We used integrated step selection analysis (iSSA) to evaluate four alternative hypotheses regarding the influence of roads on space-use behaviour across 175 elk-years of elk telemetry data, and we quantified both population-level and individual-level variations in responses. 3. We demonstrated, for the first time, how iSSA can be used to combine movement analysis in a refined approach to habitat selection. Elk responded to roads as they would natural predation risk. Elk selected areas farther from roads at all times of day with avoidance being greatest during twilight. In addition, elk sought cover and moved more when in the vicinity of roads. Road crossings were generally avoided, but this avoidance was weakest during daytime when elk were both moving and closer to roads. 4. Synthesis and applications. Energy development is transforming landscapes in western North America with the proliferation of roads, which we show is having substantial and multifaceted negative effects on elk movement and behaviour. These adverse effects can be mitigated by minimizing new road construction and by restricting traffic on roads as well as providing the protection of tree cover on elk winter ranges.

Understanding factors that influence real-world public conservation behaviors is critical for developing successful conservation policies and management actions. Citizens of Colorado, USA recently passed a ballot initiative to restore the gray wolf to its former range within the state. The >3 million votes offer an unprecedented opportunity to test factors that influenced decisions to support or oppose this conservation action. We created spatial linear regression models to assess the relationship between support for wolf restoration and (1) the presidential vote, (2) distance to conservation intervention (i.e., proposed wolf reintroduction and existing wolves), and measures of (3) livelihood and (4) demographics using precinct-level data. Our results demonstrate the strong relationship between support for wolf restoration and political support for the Democratic candidate for president in the 2020 election, and highlight how other factors, including increased age, participation in elk hunting, and proximity to the reintroduction region were associated with less support. Our findings underscore the critical role of politicization on public conservation action and the need to develop outreach and engagement strategies to mitigate polarization.

Abundance and density estimates are central to the field of ecology and are an important component of wildlife management. While many methods exist to estimate abundance from individually identifiable animals, it is much more difficult to estimate abundance of unmarked animals. One step toward noninvasive abundance estimation is the use of passive detectors such as remote cameras or acoustic recording devices. However, existing methods for estimating abundance from cameras for unmarked animals are limited by variable detection probability and have not taken full advantage of the information in camera trapping rate. We developed a time to event (TTE) model to estimate abundance from trapping rate. This estimate requires independent estimates of animal movement, so we collapsed the sampling occasions to create a space to event (STE) model that is not sensitive to movement rate. We further simplified the STE model into an instantaneous sampling (IS) estimator that applies fixed‐area counts to cameras. The STE and IS models utilize time‐lapse photographs to eliminate the variability in detection probability that comes with motion‐sensor photographs. We evaluated the three methods with simulations and performed a case study to estimate elk (Cervus canadensis) abundance from remote camera trap data in Idaho. Simulations demonstrated that the TTE model is sensitive to movement rate, but the STE and IS methods are unbiased regardless of movement. In our case study, elk abundance estimates were comparable to those from a recent aerial survey in the area, demonstrating that these new methods allow biologists to estimate abundance from unmarked populations without tracking individuals over time.

Among agents of selection that shape phenotypic traits in animals, humans can cause more rapid changes than many natural factors. Studies have focused on human selection of morphological traits, but little is known about human selection of behavioural traits. By monitoring elk (Cervus elaphus) with satellite telemetry, we tested whether individuals harvested by hunters adopted less favourable behaviours than elk that survived the hunting season. Among 45 2-year-old males, harvested elk showed bolder behaviour, including higher movement rate and increased use of open areas, compared with surviving elk that showed less conspicuous behaviour. Personality clearly drove this pattern, given that inter-individual differences in movement rate were present before the onset of the hunting season. Elk that were harvested further increased their movement rate when the probability of encountering hunters was high (close to roads, flatter terrain, during the weekend), while elk that survived decreased movements and showed avoidance of open areas. Among 77 females (2–19 y.o.), personality traits were less evident and likely confounded by learning because females decreased their movement rate with increasing age. As with males, hunters typically harvested females with bold behavioural traits. Among less-experienced elk (2–9 y.o.), females that moved faster were harvested, while elk that moved slower and avoided open areas survived. Interestingly, movement rate decreased as age increased in those females that survived, but not in those that were eventually harvested. The latter clearly showed lower plasticity and adaptability to the local environment. All females older than 9 y.o. moved more slowly, avoided open areas and survived. Selection on behavioural traits is an important but often-ignored consequence of human exploitation of wild animals. Human hunting could evoke exploitation-induced evolutionary change, which, in turn, might oppose adaptive responses to natural and sexual selection.

Migratory animals are predicted to enhance lifetime fitness by obtaining higher quality forage and/or reducing predation risk compared to non‐migratory conspecifics. Despite evidence for behavioural flexibility in other taxa, previous research on large mammals has often assumed that migratory behaviour is a fixed behavioural trait. Migratory behaviour may be plastic for many species, although few studies have tested for individual‐level flexibility using long‐term monitoring of marked individuals, especially in large mammals such as ungulates. We tested variability in individual migratory behaviour using a 10‐year telemetry data set of 223 adult female elk (Cervus elaphus) in the partially migratory Ya Ha Tinda population in Alberta, Canada. We used net squared displacement (NSD) to classify migratory strategy for each individual elk‐year. Individuals switched between migrant and resident strategies at a mean rate of 15% per year, and migrants were more likely to switch than residents. We then tested how extrinsic (climate, elk/wolf abundance) and intrinsic (age) factors affected the probability of migrating, and, secondly, the decision to switch between migratory strategies. Over 630 individual elk‐years, the probability of an individual elk migrating increased following a severe winter, in years of higher wolf abundance, and with increasing age. At an individual elk level, we observed 148 switching events of 430 possible transitions in elk monitored at least 2 years. We found switching was density‐dependent, where migrants switched to a resident strategy at low elk abundance, but residents switched more to a migrant strategy at high elk abundance. Precipitation during the previous summer had a weak carryover effect, with migrants switching slightly more following wetter summers, whereas residents showed the opposite pattern. Older migrant elk rarely switched, whereas resident elk switched more frequently to migrate at older ages. Our results show migratory behaviour in ungulates is an individually variable trait that can respond to intrinsic, environmental and density‐dependent forces. Different strategies had opposing responses to density‐dependent and intrinsic drivers, providing a stabilizing mechanism for the maintenance of partial migration and demographic fitness in this population.

Context Connectivity has become a top conservation priority in response to landscape fragmentation. Many methods have been developed to identify areas of the landscape with high potential connectivity for wildlife movement. However, each makes different assumptions that may produce different predictions, and few comparative tests against empirical movement data are available. Objectives We compared predictive performance of the most-used connectivity models, cost-distance and circuit theory models. We hypothesized that cost-distance would better predict elk migration paths, while circuit theory would better predict wolverine dispersal paths, due to alignment of the methods’ assumptions with the movement ecology of each process. Methods We used each model to predict elk migration paths and wolverine dispersal paths in the Greater Yellowstone Ecosystem, then used telemetry data collected from actual movements to assess predictive performance. Methods for validating connectivity models against empirical data have not been standardized, thus we applied and compared four alternative methods. Results Our findings generally supported our hypotheses. Circuit theory models consistently predicted wolverine dispersal paths better than cost-distance, though cost-distance models predicted elk migration paths only slightly better than circuit theory. In most cases, our four validation methods supported similar conclusions, but provided complementary perspectives. Conclusions We reiterate suggestions that alignment of connectivity model assumptions with focal species movement ecology is an important consideration when selecting a modeling approach for conservation practice. Additional comparative tests are needed to better understand how relative model performance may vary across species, movement processes, and landscapes, and what this means for effective connectivity conservation.