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Wildlife viewing within protected areas is an increasingly popular recreational activity. Management agencies are often tasked with providing these opportunities, yet quantitative analyses of factors influencing wildlife sightings are lacking. We analyzed locations of GPS-collared wolves and wolf sightings from 2945 trips in Denali National Park and Preserve, Alaska, USA, to provide a mechanistic understanding of how viewing opportunities are influenced by attributes of wolves and physical, biological, and harvest characteristics. We found that the presence of masking vegetation, den site proximity to the road, pack size, and presence of a wolf harvest closure adjacent to the park affected wolf sightings, and the influence of den proximity on sightings depended on harvest management. Wolf sightings increased with den site proximity to the road in years with a harvest closure adjacent to the park but not in the absence of the closure. The effect of the harvest closure on sightings was similar in magnitude to an increase in pack size by two wolves or a more than a two-fold decrease in masking vegetation. These findings were consistent across a 10-fold change in spatial resolution. Quantitative analysis of the factors influencing wildlife sightings provides valuable insight for agencies tasked with managing viewing opportunities.

Annual variation in phenology can have profound effects on the behavior of animals. As climate change advances spring phenology in ecosystems around the globe, it is becoming increasingly important to understand how animals respond to variation in the timing of seasonal events and how their responses may shift in the future. We investigated the influence of spring phenology on the behavior of migratory, barren‐ground caribou (Rangifer tarandus), a species that has evolved to cope with short Arctic summers. Specifically, we examined the effect of spring snow melt and vegetation growth on the current and potential future space‐use patterns of the Porcupine Caribou Herd (PCH), which exhibits large, inter‐annual shifts in their calving and post‐calving distributions across the U.S.–Canadian border. We quantified PCH selection for snow melt and vegetation phenology using machine learning models, determined how selection resulted in annual shifts in space‐use, and then projected future distributions based on climate‐driven phenology models. Caribou exhibited strong, scale‐dependent selection for both snow melt and vegetation growth. During the calving season, caribou selected areas at finer scales where the snow had melted and vegetation was greening, but within broader landscapes that were still brown or snow covered. During the post‐calving season, they selected vegetation with intermediate biomass expected to have high forage quality. Annual variation in spring phenology predicted major shifts in PCH space‐use. In years with early spring phenology, PCH predominately used habitat in Alaska, while in years with late phenology, they spent more time in Yukon. Future climate conditions were projected to advance spring phenology, shifting PCH calving and post‐calving distributions further west into Alaska. Our results demonstrate that caribou selection for habitat in specific phenological stages drive dramatic shifts in annual space‐use patterns, and will likely affect future distributions, underscoring the importance of maintaining sufficient suitable habitat to allow for behavioral plasticity., The Porcupine Caribou Herd spends their summer calving and post‐calving seasons on the Arctic coastal plain of Alaska and Yukon but can exhibit substantial annual shifts in their precise distributions. Our models demonstrated that annual variation in spring snow​ melt and vegetation phenology drove variation in summer range locations. Based on climate projections, the future summer ranges were predicted to shift further west and north into the Alaskan coastal plain due to advancing spring phenology, underscoring the need for sufficient habitat to allow for behavioral adaptation in the changing environment.

Muskoxen (Ovibos moschatus) are thought to be highly effective at defending themselves from predators. However, a decline in muskox abundance in northeastern Alaska, USA, that coincided with several instances of grizzly bear (Ursus arctos) predation observed during 2000–2006 raised concerns about the effects of predation on this population. In response, from 2007 to 2011 we estimated rates of reproduction and survival and determined rates and causes of muskox mortality on the arctic coastal plain of northeastern Alaska. Annual counts of muskox abundance (x = 191) and estimates of population growth (x = 0.94) indicated a stable or slowly declining population. Annual natality ranged from 0.45 to 0.86 (x = 0.68) births/adult female, whereas annual survival ranged from 0.40 to 0.63 (x = 0.49) for calves and from 0.73 to 0.91 (x = 0.83) for adult females. Predation by grizzly bears was the most common cause of death among cases where a cause could be identified, accounting for 58% and 62% of deat...

Large predators often suppress ungulate population growth, but they may also suppress the abundance of smaller predators that prey on neonatal ungulates. Antagonistic interactions among predators may therefore need to be integrated into predator–prey models to effectively manage ungulate–predator systems. We present a modeling framework that examines the net impact of interacting predators on the population growth rate of shared prey, using interactions among wolves Canis lupus, coyotes Canis latrans and Dall sheep Ovis dalli dalli as a case study. Wolf control is currently employed on approximately 16 million ha in Alaska to increase the abundance of ungulates for human harvest. We hypothesized that the positive effects of wolf control on Dall sheep population growth could be counteracted by increased levels of predation by coyotes. Coyotes and Dall sheep adult females (ewes) and lambs were radiocollared in the Alaska Range from 1999–2005 to estimate fecundity, age-specific survival rates, and causes of mortality in an area without wolf control. We used stage-structured population models to simulate the net effect of wolf control on Dall sheep population growth (λ). Our models accounted for stage-specific predation rates by wolves and coyotes, compensatory mortality, and the potential release of coyote populations due to wolf control. Wolves were the main predators of ewes, coyotes were the main predators of lambs, and wolves were the main source of mortality for coyotes. Population models predicted that wolf control could increase sheep λ by 4% per year in the absence of mesopredator release. However, if wolf control released coyote populations, our models predicted that sheep λ could decrease by up to 3% per year. These results highlight the importance of integrating antagonistic interactions among predators into predator–prey models, because the net effect of predator management on shared prey can depend critically on the strength of mesopredator release.

The muskox ( Ovibos moschatus ) population inhabiting the eastern North Slope (ENS) of Alaska, US declined dramatically during 1999-2006, whereas populations in western Alaska (WA) were stable or increasing. To understand morbidity and mortality factors contributing to the decline, Alaska Department of Fish and Game conducted pathologic investigations of carcasses from 2005 until 2008. Additionally, archived sera from both ENS and WA muskoxen collected during 1984-92, before the documented beginning of the ENS decline; sera collected during 2000, near the beginning of the decline; and contemporary sera (from live capture-release, adult females) collected during 2006, 2007, and 2008 were analyzed to determine whether prevalence of antibody to potential pathogens differed in the two areas or changed over time. The pathogens investigated were those that were believed could cause lameness or poor reproduction or adversely affect general health. Furthermore, trace mineral levels, hemograms, and gastrointestinal parasites were evaluated in live adult females captured 2006-08. Pathologic investigations identified several comorbid conditions, including predation, polyarthritis caused by or consistent with Chlamydophila spp. infection, hoof lesions, copper deficiency, contagious ecthyma, verminous pneumonia, hepatic lipidosis suggestive of negative energy balance, and bacterial bronchopneumonia due to Trueperella pyogenes and Bibersteinia trehalosi . Pathogens suspected to be newly introduced in the ENS muskox population on the basis of serologic detection include bovine viral diarrhea, respiratory syncytial virus, Chlamydophila spp., Brucella spp., Coxiella burnetii , and Leptospira spp., whereas parainfluenza virus-3 antibody prevalence has increased in the WA population. Although multiple disease syndromes were identified that contributed to mortality and, in combination, likely limited the ENS muskox population, further holistic investigations of disease agents, trace mineral status, and nutritional factors in conjunction with intensive demographic and environmental analyses would provide a better understanding of factors that influence Alaskan muskox populations.

Migration is an important component of the life history of many animals, but persistence of large-scale terrestrial migrations is being challenged by environmental changes that fragment habitats and create obstacles to animal movements. In northern Alaska, the Central Arctic herd (CAH) of barren-ground caribou (Rangifer tarandus granti) is known to migrate over large distances, but the herd's seasonal distributions and migratory movements are not well documented. From 2003-2007, we used GPS radio-collars to determine seasonal ranges and migration routes of 54 female caribou from the CAH. We calculated Brownian bridges to model fall and spring migrations for each year and used the mean of these over all 4 years to identify areas that were used repeatedly. Annual estimates of sizes of seasonal ranges determined by 90% fixed kernel utilization distributions were similar between summer and winter (X̅ = 27,929 SE = 1,064 and X̅ = 26,585 SE = 4912 km2, respectively). Overlap between consecutive summer and winter ranges varied from 3.3-18.3%. Percent overlap between summer ranges used during consecutive years (X̅ = 62.4% SE = 3.7%) was higher than for winter ranges (X̅ = 42.8% SE = 5.9%). Caribou used multiple migration routes each year, but some areas were used by caribou during all years, suggesting that these areas should be managed to allow for continued utilization by caribou. Restoring migration routes after they have been disturbed or fragmented is challenging. However, prior knowledge of movements and threats may facilitate maintenance of migratory paths and seasonal ranges necessary for long-term persistence of migratory species.

Identifying links between nutritional condition of individuals and population trajectories greatly enhances our understanding of the ecology, conservation, and management of wildlife. For northern ungulates, the potential impacts of a changing climate to populations are predicted to be nutritionally mediated through an increase in the severity and variance in winter conditions. Foraging conditions and the availability of body protein as a store for reproduction in late winter may constrain productivity in northern ungulates, yet the link between characteristics of wintering habitats and protein status has not been established for a wild ungulate. We used a non-invasive proxy of protein status derived from isotopes of N in excreta to evaluate the influence of winter habitats on the protein status of muskoxen in three populations in Alaska (2005–2008). Multiple regression and an information-theoretic approach were used to compare models that evaluated the influence of population, year, and characteristics of foraging sites (components of diet and physiography) on protein status for groups of muskoxen. The observed variance in protein status among groups of muskoxen across populations and years was partially explained (45%) by local foraging conditions that affected forage availability. Protein status improved for groups of muskoxen as the amount of graminoids in the diet increased (−0.430 ± 0.31, β± 95% CI) and elevation of foraging sites decreased (0.824 ± 0.67). Resources available for reproduction in muskoxen are highly dependent upon demographic, environmental, and physiographic constraints that affect forage availability in winter. Due to their very sedentary nature in winter, muskoxen are highly susceptible to localized foraging conditions; therefore, the spatial variance in resource availability may exert a strong effect on productivity. Consequently, there is a clear need to account for climate–topography effects in winter at multiple scales when predicting the potential impacts of climatic shifts on population trajectories of muskoxen.

Indirect interactions among species can strongly influence population dynamics and community structure but are often overlooked in management of large mammals. We estimated survival of Dall's sheep (Ovis dalli) in the central Alaska Range, USA, during years of differing snowshoe hare (Lepus americanus) abundance to test whether indirect interactions with a cyclic hare population affect Dall's sheep either negatively, by subsidizing predators (apparent competition), or positively, by diverting predation (apparent commensalism). Annual survival of adult female sheep was consistently high (0.85 for all yr and age classes combined). In contrast, annual estimates of lamb survival ranged from 0.15 to 0.63. The main predators of lambs were coyotes (Canis latrans) and golden eagles (Aquila chrysaetos), which rely on hares as their primary food and prey on lambs secondarily. Coyotes and eagles killed 78% of 65 radiocollared lambs for which cause of death was known. Lamb survival was negatively related to hare abundance during the previous year, and lamb survival rates more than doubled when hare abundance declined, supporting the hypothesis of predator-mediated apparent competition between hares and sheep. However, stage-specific predation and delays in predator responses to changes in hare numbers led to a positive relationship between abundance of adult Dall's sheep and hares. Lacking reliable estimates of survival, a manager might erroneously conclude that hares benefit sheep. Thus, support for different indirect effects can be obtained from different types of data, which demonstrates the need to determine the mechanisms that create indirect interactions. Long-term survey data suggest that predation by coyotes is limiting this sheep population below levels typical when coyotes were rare or absent. Understanding the nature of indirect interactions is necessary to effectively manage complex predator–prey communities.

Faecal genotyping has been proposed as a method to examine the diets of individuals, but this application has been virtually unexplored by wildlife biologists. We used faecal genotyping and conventional scat analysis to determine the diets of 42 coyotes Canis latrans belonging to nine social groups in Alaska. We use rarefaction to examine the effect of scat sample size on the accuracy and precision of individual diets, and we simulate diets from scats to determine how diet richness and evenness affect sample size requirements. We then demonstrate the utility of this technique by examining variation in diet among individual coyotes and social groups in relation to prey availability. Estimates of diet diversity and composition were highly variable when

The thinhorn sheep (Ovis dalli ssp.) provides a rare example of a North American large mammal that occupies most of its native range and maintains close to ancestral population size. There are currently two recognized subspecies, Dall's sheep (O. d. dalli) and Stone's sheep (O. d. stonei), the validity of which remains uncertain. We investigated the spatial genetic structure of thinhorn sheep populations representing both subspecies by genotyping individuals (n = 919) from across the species range at 12 variable microsatellite loci. We found high levels of genetic diversity within (HE = 0.722) and significant genetic structure among the 24 sampled areas (FST = 0.160). Genetic distance measures and Bayesian clustering analyses revealed the presence of at least eight subpopulations that are delineated by mountain range topology. A strong overall pattern of isolation-by-distance is evident across the sampling range (r = 0.75, P

We hypothesized that the relative availability of meat, indicated by contribution to the diet, would be positively related to body size and population productivity of North American brown, or grizzly, bears (Ursus arctos). Dietary contributions of plant matter and meat derived from both terrestrial and marine sources were quantified by stable-isotope analysis (δ13C and δ15N) of hair samples from 13 brown bear populations. Estimates of adult female body mass, mean litter size, and population density were obtained from two field studies of ours and from other published reports. The populations ranged from largely vegetarian to largely carnivorous, and food resources ranged from mostly terrestrial to mostly marine (salmon, Oncorhynchus spp.). The proportion of meat in the diet was significantly correlated with mean adult female body mass (r = 0.87, P < 0.01), mean litter size (r = 0.72, P < 0.01), and mean population density (r = 0.91, P < 0.01). Salmon was the most important source of meat for the largest, most carnivorous bears and most productive populations. We conclude that availability of meat, particularly salmon, greatly influences habitat quality for brown bears at both the individual level and the population level.

We determined characteristics of natal dens used by radio-collared fishers in southcentral Maine. Twelve adult (≥2 yr old) females were monitored for periods of 1-5 yr each during 1984-1989. Estimated whelping dates of 12 litters were March 3-April 1, and females used 1-5 natal dens each until denning ended in early June. All 33 natal dens were in tree cavities on upland sites. Hardwoods composed 94% of the den trees, with aspens accounting for 52%. We recommend that forestry practices allow for a continued supply of mature and decadent hardwoods > 40 cm dbh to replace cavity trees that fall. Where cavity trees must be removed, cutting should be done outside the March-June denning period to avoid disturbance or mortality of fisher litters. North. J. Appl. For. 13(2): 79-83.

We present a method of comparing data on habitat use and availability that allows availability to differ among observations. This rnethod is applicable when habitats change over time and when animals are unable to move throughout a predeter- mined study area between observations. We used maximum-likelihood techniques to de- rive an index that estimates the probability that each habitat type would be used if all were equally available. We also demonstrate how these indices can be used to compare relative use of available habitats, assign them ranks, and assess statistical differences between pairs of indices. The set of these indices for all habitats can be compared between groups of animals that represent different seasons, sex or age classes, or experimental treatments. This method allows quantitative comparisons among types and is not affected by arbitrary decisions about which habitats to include in the study. We provide an example by comparing the availability of four categories of sea ice concentration to their use by adult female polar bears (Ursus maritimus), whose movements were monitored by satellite radio tracking in the Bering and Chukchi Seas during 1990. Use of ice categories by bears was nonrandom, and the pattern of use differed between spring and late summer seasons.

The desire to see free ranging large carnivores in their natural habitat is a driver of tourism in protected areas around the globe. However, large carnivores are wide-ranging and subject to human-caused mortality outside protected area boundaries. The impact of harvest (trapping or hunting) on wildlife viewing opportunities has been the subject of intense debate and speculation, but quantitative analyses have been lacking. We examined the effect of legal harvest of wolves (Canis lupus) along the boundaries of two North American National Parks, Denali (DNPP) and Yellowstone (YNP), on wolf viewing opportunities within the parks during peak tourist season. We used data on wolf sightings, pack sizes, den site locations, and harvest adjacent to DNPP from 1997-2013 and YNP from 2008-2013 to evaluate the relationship between harvest and wolf viewing opportunities. Although sightings were largely driven by wolf population size and proximity of den sites to roads, sightings in both parks were significantly reduced by harvest. Sightings in YNP increased by 45% following years with no harvest of a wolf from a pack, and sightings in DNPP were more than twice as likely during a period with a harvest buffer zone than in years without the buffer. These findings show that harvest of wolves adjacent to protected areas can reduce sightings within those areas despite minimal impacts on the size of protected wolf populations. Consumptive use of carnivores adjacent to protected areas may therefore reduce their potential for non-consumptive use, and these tradeoffs should be considered when developing regional wildlife management policies.

Most activity of adult fishers ( Martes pennanti ) occurred shortly before sunrise and after sunset, but some activity occurred throughout the day and night. Males and females showed similar amounts of activity, and both were active more frequently in summer than winter. Movements of males were greatest during the spring breeding season; nonreproductive females moved similar distances during all seasons. Eleven maternal dens were in tree cavities; the denning period lasted 8–12 weeks from March through May. The maximum annual parturition rate among females ≥2 years old was 75% ( n = 4). This was less than pregnancy rates indicated by corpora lutea, and suggested that some pregnancies were unsuccessful. We hypothesize that delayed implantation allows mating to occur at a favorable time for adults, and births to occur when offspring have the maximum time for development before winter.

Reliable population estimates are necessary for effective conservation and management, and faecal genotyping has been used successfully to estimate the population size of several elusive mammalian species. Information such as changes in population size over time and survival rates, however, are often more useful for conservation biology than single population estimates. We evaluated the use of faecal genotyping as a tool for monitoring long-term population dynamics, using coyotes (Canis latrans) in the Alaska Range as a case study. We obtained 544 genotypes from 56 coyotes over 3 years (2000-2002). Tissue samples from all 15 radio-collared coyotes in our study area had > or = 1 matching faecal genotypes. We used flexible maximum-likelihood models to study coyote population dynamics, and we tested model performance against radio telemetry data. The staple prey of coyotes, snowshoe hares (Lepus americanus), dramatically declined during this study, and the coyote population declined nearly two-fold with a 1(1/2)-year time lag. Survival rates declined the year after hares crashed but recovered the following year. We conclude that long-term monitoring of elusive species using faecal genotyping is feasible and can provide data that are useful for wildlife conservation and management. We highlight some drawbacks of standard open-population models, such as low precision and the requirement of discrete sampling intervals, and we suggest that the development of open models designed for continuously collected data would enhance the utility of faecal genotyping as a monitoring tool.

We examined the historical and current diets of brown bears (Ursus arctos) and black bears (U. americanus) in the Greater Yellowstone Ecosystem, Glacier National Park and immediately adjacent areas of national forests, Cabinet-Yaak mountains of northwestern Montana and northern Idaho, Blackfeet and Flathead Indian reservations east and south of Glacier National Park, the Kenai Peninsula of Alaska, and the southwestern states of Colorado, New Mexico, and Arizona. Dietary estimates are an essential first step in understanding variation in productivity and density of current populations and, therefore, predicting success of reintroduced populations. Hair or bone samples from 14 federal or state agencies, museums, and universities were examined via stable isotope analyses to quantify the importance of animal and plant resources to sympatric brown and black bears. Stable isotope analyses have numerous advantages over fecal analyses or direct observation because diets of (1) individuals and thereby specific age and sex classes within a population can be compared, and (2) long-dead bears can be compared to living bears to evaluate historical changes in ecosystems. Meat content of current brown bear diets, which varied extensively between individuals and age and sex classes in all populations, averaged 51 ± 19% (x ± SD) for subadult and adult males and females in the Greater Yellowstone Ecosystem and 11 ± 14% in Glacier National Park and Cabinet-Yaak mountains. Within these ecosystems, adult male brown bears were more carnivorous than any other age or sex class. Brown bears that used easily obtained, abundant meat sources had dietary meat contents generally ≥70%. The meat:plant ratios in the diets of historical Greater Yellowstone Ecosystem bears (1,000 YBP) and Glacier National Park bears (1908-18) were similar to ratios in current diets. Sympatric black bears in the Wyoming, Montana, and Idaho ecosystems had dietary meat:plant ratios that were not different from all brown bear age and sex classes, except adult males. Alaskan black bears made extensive use of salmon (Oncorhynchus spp.) when brown bears were rare (53 ± 28% of the diet), but did not use salmon when sympatric with abundant brown bears.

We studied natal dispersal of fishers (Martes pennanti) in a harvested population in southcentral Maine during 1984-90 because of concern over the high level of harvest and a lack of information about fisher dispersal. Probability that an individual would disperse by the end of its first year was 73 and 100% for males and females, respectively (n = 21 M, 12 F). However, 32% of males and no females dispersed before the age of 9 months. Mean distance between natal and adult home ranges did not differ (t = 0.16, P = 0.88) between males (n = 8, x = 10.8 km, range = 4.1-19.5) and females (n = 5, x = 11.2 km, range = 5.0-18.9). Dispersal, in combination with intrasexual territoriality of adults, may limit fisher density and competition for food

We investigated habitat selection patterns of the great bustard Otis tarda in a dynamic agricultural landscape in southern Portugal. Combining data from 26 bustard counts with habitat mapping, we used resource selection functions to characterise habitat selection in two areas with different agricultural uses. Selection patterns were compared among areas, seasons (breeding, post-breeding and winter), and flock types (male, female and mixed) during the breeding season. Seasonal differences in selection patterns generally parallelled changes in estimated food availability. Stubbles (i.e. recently harvested fields) and stream margins were preferentially selected by all bustards during the post-breeding period, whereas cereal and fallow fields were selected during winter. During the breeding season, males selected fallow fields more than other habitat types, whereas females selected cereal fields. Habitat selection seemed to be influenced by habitat availability, with birds showing stronger selection for preferred habitats in the areas where they were less available. Great bustards used different habitat types throughout the agricultural year, and we recommend that habitat management promotes a rotational crop system that includes cereal and fallow fields.