A novel shrew was discovered recently in Alaska and described based on morphological characters as Sorex yukonicus. This species is closely allied to Sorex minutissimus, a widespread shrew ranging through Eurasia. Together their distribution spans Beringia, a large Pleistocene nonglaciated area that connected Asia and North America. Beringia was repeatedly divided due to raised sea levels during Pleistocene interglacials and subsequently reconnected during glacials. We tested predictions related to the influence of large-scale geologic events on genetic variability through a phylogeographic analysis of both species of shrew using evidence from 3 independent genetic loci. We found low genetic divergence between S. minutissimus and S. yukonicus across continents. However, major phylogeographic breaks were found for Eurasian and Maritime Northeast Asia populations. Neither species is reciprocally monophyletic for any of the loci examined. Coalescence times for all pairwise population comparisons within both species fall within the Wisconsinan–Weichselian glacial (<130 thousand years ago), and significant population expansion estimates date to the Holocene suggesting that divergence between these taxa is minimal and may not warrant recognition of 2 distinct species. Phylogeographic relationships and sequence divergence estimates place populations of North American S. yukonicus and Siberian S. minutissimus as most closely related, and together they are sister to European S. minutissimus. We conclude that populations east and west of the Bering Strait represent a single Holarctic species, S. minutissimus. Temporal changes in range based on ecological niche predictions and a comparative assessment of other codistributed taxa provide a preliminary view of potential Last Glacial Maximum refugia in northern Asia.

Examining species boundaries using data from multiple independent sources is an appropriate and robust method to identify genetically isolated evolutionary units. We used 5 data sets—cytochrome b (Cytb), cytochrome c oxidase (COI), amplified fragment length polymorphisms (AFLPs), karyotypes, and morphology—to estimate phylogenetic relationships and species limits within woolly bats, genus Kerivoula, from Southeast Asia. We genetically analyzed 54 specimens of Kerivoula from Malaysia, assigned to 6 of the 10 species currently reported from the country. Phylogenetic analyses of nuclear AFLPs (33 specimens) and mitochondrial DNA sequences from Cytb (51 specimens) and COI (48 specimens) resulted in similar statistically supported species-level clades with minimal change in branching order. Using comparisons of cranial and dental morphology and original species descriptions, we assigned the resulting phylogenetic clades to K. hardwickii, K. intermedia, K. lenis, K. minuta, K. papillosa, K pellucida, and 1 unidentified species. Karyotypes further documented variability among the 6 clades. Five different karyotypes were identified, with 2 species having indistinguishable karyotypes. We compared our COI gene sequence data to 110 specimens of Kerivoula from Southeast Asia made available by researchers of the Barcode of Life Database. Our Cytb and AFLP species identifications were congruent with those in the COI database. Intraspecific geographic variation of about 5–7% sequence divergence was observed in Cytb and COI genes within both K. hardwickii and K. minuta. Relaxed molecular clock analyses indicated a late Oligocene to early Miocene origin of the Kerivoulinae with intraspecific diversification events coinciding with the late Pliocene and Pleistocene epochs in at least 6 species. Specimens from Sabah (northeastern Borneo) showed relatively high genetic divergence compared to those between Peninsular Malaysia and Sarawak (southwestern Borneo), indicating Pleistocene or Pliocene refugia in Borneo. We conclude that at least 1 distinct lineage of Kerivoula is yet to be described from Borneo and that the intraspecific geographic variation in some species agrees with previous studies on the diversification of flora and fauna in Borneo.

A paucity of useful characters, morphological convergence, and potential rapid radiation has hindered systematists in elucidating evolutionary relationships within Vespertilioninae. In this study >8,500 base pairs of digenomic DNA for 111 taxa were sequenced and analyzed using maximum-parsimony and Bayesian phylogenetic methods to construct trees and reexamine hypotheses of supergeneric evolutionary relationships in Vespertilioninae. Results of these analyses validate monophyly of Vespertilioninae with the exclusion of Myotis and support recognition of 6 tribes: Antrozoini, Lasiurini, Scotophilini, Vespertilionini, and 2 new unnamed tribal clades, the perimyotine group and the hypsugine group. Tree topologies indicate a Nycticeiini–Eptesicini group, but this clade is not supported. The heuristically pleasing tribe Plecotini also is unresolved in these analyses. These results provided further support and greater resolution for previously proposed hypotheses of Vespertilioninae evolution based on mitochondrial DNA, and although deep branching patterns are not fully resolved, these data increase our understanding of the evolution of this ecologically important and diverse group of bats.

Microtus pennsylvanicus is represented in Mexico only by the Chihuahuan meadow vole (M. p. chihuahuensis), known from only 1 disjunct population in a small and isolated marsh in the arid lands of northern Chihuahua. Livetrapping conducted between 2000 and 2004 provided no specimens of M. p. chihuahuensis, nor was any sign of this vole observed. By the end of this study the marsh providing water had been drained, thereby destroying the vole's habitat. Surveys of other marshes in northern Chihuahua also failed to produce evidence of the species. We therefore conclude that M. p. chihuahuensis has been extirpated from its only known locality. Using “ancient” DNA from museum specimens we evaluated genetic divergence between museum specimens of M. p. chihuahuensis and 46 extant Microtus species and subspecies. Our results support the subspecific status of M. p. chihuahuensis. The loss of this subspecies is an example of population extinction, a very severe form of biodiversity loss. Until recently such losses have been mostly neglected.

We evaluated systematic relationships among most of the subspecies of the long-haired sigmodontine mouse Abrothrix longipilis in Chile. We sequenced the complete cytochrome-b gene and 634 base pairs of intron 7 of the β-fibrinogen gene from specimens from 17 localities along the distributional range of A. longipilis. Phylogenetic analyses confirm Abrothrix sanborni, once considered a subspecies of A. longipilis, as a valid species. In the latter taxon we obtained a structured phylogenetic pattern that recovered most of the geographic races traditionally recognized for this mouse. However, strong differentiation was found between A. l. longipilis from Mediterranean Chile and subspecies from the Temperate and Patagonian Forests in the south, suggesting that the former could constitute a different species. We concluded that historical events (glaciations), coupled with local selection pressures (different ecogeographic zones), might account for the current geographic pattern of variation in A. longipilis.

The eastern fox squirrel (Sciurus niger) occurs naturally over most of eastern North America. The striking patterns of geographic variation in size and coat color displayed by this species are consistent with a hypothesis of southward range contraction and isolation in 2 refugia (in Texas and Florida) during the Last Glacial Maximum, followed by northward range expansion after the glaciers receded. Similar hypotheses have been proposed to explain the patterns in phylogeographic structure exhibited by many plants and animals in eastern North America. We analyzed DNA sequence variation in a 402–base-pair segment of the mitochondrial cytochrome-b gene in populations throughout the species' range. Despite our broad geographic sampling, we failed to detect any phylogeographic structure. Unique haplotypes differed from high-frequency haplotypes by only 1 or 2 base pairs, producing a starlike phylogeny of haplotypes. Genetic variation within populations and the species as a whole was characterized by high haplotype diversity and low nucleotide diversity. Taken together, our data indicate that the eastern fox squirrel underwent a rapid range expansion and rapid morphological divergence within the past 14,000 years.

Populations of pronghorn (Antilocapra americana) are subjected to multiple forms of density-dependent and density-independent regulation. Little is known about the combined effects of these variables across multiple populations throughout the landscape. The objectives of this study were to examine long-term trends in density and recruitment in pronghorn and to assess how different forms of regulation influence these trends. We used multiple density-dependent and density-independent explanatory variables in a model selection process to explain variation in pronghorn density and July fawn ∶ doe ratios from 1955 to 1993 in 4 pronghorn management units in Nebraska. We also investigated levels of density-dependent feedback in each management unit. Examination of long-term population trends suggested that pronghorn populations in Nebraska exhibited an Allee effect (inverse density dependence), in which population growth decreases as density decreases. We suggest that variation in rangeland condition and presence of adequate forage could explain the presence of the Allee effect. Both density-dependent and density-independent variables affected pronghorn populations, with density of cattle, spring precipitation, abundance of winter wheat, and hunting harvest most important for explaining fluctuations in pronghorn densities. Snow depth and density of cattle best explained yearly July fawn ∶ doe ratios. The importance of each factor was variable across the different management units. Management objectives aimed at improving access to and abundance of food resources during times when rangeland condition is poor could prevent drastic declines in pronghorn populations.

Narwhals (Monodon monoceros L.) occur in the Atlantic sector of the Arctic where for centuries they have been subject to subsistence hunting by Inuit in Greenland and Canada. Scientific advice on the sustainable levels of removals from narwhal populations provides the basis for quotas implemented in both Greenland and Canada. The scientific advice relies heavily on extensive aerial surveys that are the only feasible way to acquire data on narwhal densities and abundance throughout their range. In some areas lack of information on abundance, in combination with high exploitation levels, has caused conservation concerns leading to restrictions on the international trade in narwhal tusks. Narwhals also are regarded as highly sensitive to habitat disturbance caused by global warming. This study analyzed data from aerial sighting surveys covering four major narwhal hunting grounds in Greenland. The surveys were conducted as double observer experiments with 2 independent observation platforms, 1 at the front and 1 at the rear of the survey plane. The sighting data were analyzed using mark–recapture distance sampling techniques that allow for correction for whales that were missed by the observers. The surveys also were corrected for animals that were submerged during the passage of the survey plane, using diving and submergence data from satellite-linked time–depth recorders deployed on 2 free-ranging narwhals. The abundance of narwhals on the wintering ground in West Greenland in 2006 was 7,819 (95% confidence interval [CI]: 4,358–14,029). The abundances of narwhals in Inglefield Bredning and Melville Bay, northwest Greenland in 2007 were 8,368 (95% CI: 5,209–13,442) and 6,024 (95% CI: 1,403–25,860), respectively. The abundance of narwhals in East Greenland in 2008 was 6,444 (95% CI: 2,505–16,575). These surveys provide the first estimates of narwhal abundance from important hunting areas in East and West Greenland and provide larger and more complete estimates from previously surveyed hunting grounds in Inglefield Bredning. The estimates can be used for setting catch limits for the narwhal harvest in West and East Greenland and as a baseline for examining the effects of climate change on narwhal abundance.

The striped hyena (Hyaena hyaena), despite being a threatened species, frequently occurs in human-dominated landscapes of India's Rajasthan State. We estimated hyena densities using photographic capture–recapture sampling to identify key ecological factors influencing hyena abundances in such areas. Our 2 study sites (307 km² in Kumbhalgarh Wildlife Sanctuary and 218 km² in Esrana Forest Range) had different topographies and levels of human disturbances. We proposed explicit hypotheses regarding effects of livestock densities and topographic features on hyena abundances. We tested these hypotheses by examining the correspondence of estimated hyena densities to food availability in the form of livestock carcasses and potential refugia offered by hilly terrain. Sampling efforts of 548 and 538 camera-trap nights were invested in Kumbhalgarh and Esrana, respectively. Density estimates (hyenas/100 km²) based on capture–recapture sampling were higher (6.5 ± 2.6 SE) for Kumbhalgarh than Esrana (3.67 ± 0.3 SE). Our results supported the prediction that denning refugia in hilly terrain sustain higher hyena densities, but the prediction that higher livestock densities maintain higher hyena densities was not supported. Because the striped hyena is a threatened species for which few data exist, our findings have major potential utility for range-wide conservation of the species.

Reproductive characteristics of a wildlife population are typically sensitive to changes in environmental conditions and intrinsic factors. Knowledge of these relationships is critical for understanding population dynamics and effective long-term management of a population. We examined temporal variation in reproductive parameters of an abundant, genetically compromised, and high-density population of koalas (Phascolarctos cinereus) on Kangaroo Island, South Australia, over 3 breeding seasons spanning 9 years: November–May of 1997–1998, 2005–2006, and 2006–2007. Timing of the breeding season was consistent between years, but fecundity, sex ratio of young, and the percentage of independent females (those not accompanying a lactating female) < 6 kg varied. Fecundity was lower than in other island populations, suggesting that the quality and distribution of food resources or inbreeding may be impacting the Kangaroo Island population. We did not test for Chlamydophila (synonym  =  Chlamydia), and clinical signs of this disease were not reported for any of the koalas in this study. However, historical evidence of Chlamydophila-infected koalas on Kangaroo Island exists, and the potential impact of this disease on fecundity warrants further investigation.

We examined growth differences in external and skull morphology between spring and autumn cohorts of the large Japanese field mouse (Apodemus speciosus). We analyzed 271 specimens from the Kyoto population, which had 2 discrete breeding periods, spring and autumn. Growth differences between the 2 cohorts were found in body weight and head and body length. The spring cohort grew rapidly in the summer following birth, whereas the autumn cohort showed growth inhibition during the autumn and winter soon after birth and rapid growth the following spring and summer. The centroid sizes (CSs) of the cranium and mandible showed similar growth patterns, but no significant postweaning growth was observed in ear length or hind-foot length. Cranium and mandible shape showed weak growth changes related to increases in CS. Decreases in mean body size during the winter were found only in males from the spring cohort. No significant difference was found between adult samples from the spring and autumn cohorts in either external or skull morphology. We suggest that insufficient food resources is the major factor causing the growth inhibition in the autumn cohort and postulate that winter survivability, which is related to reproductive competition, explains the body-size reduction in winter observed in males from the spring cohort.

Leopards (Panthera pardus) are a poorly understood, solitary felid, and additional study could provide novel insights into both evolution and conservation management. We studied the reproductive biology of 7 adult female and 2 adult male leopards on Karongwe, South Africa, from 1999 to 2005. We intensively researched copulatory biology from 2001 to 2003, during which we observed 19 consortships and 4,855 copulations (1,809 copulations visually) during 2,449 h of following consort pairs. Leopards copulated on average 4 times per hour, with an average of 256 copulations per consortship. Conception rate was low, resulting, on average, after 2.3 consortships (SE  =  0.4 consortships). All reproductive parameters except gestation length were shorter than those in published literature, which we suspect reflected a facultative response to superabundant resources. Although females produced the expected 1.6 cubs per year, lifetime reproductive rates on Karongwe Reserve were approximately half that reported elsewhere due to lower female survival resulting from intraspecific factors. These results offer encouragement for founding new populations of endangered felids in areas of high prey availability and resource abundance, provided factors affecting population regulation can be managed.

Male Juan Fernández fur seals (Arctocephalus philippii) are significantly larger than females at birth and show extreme dimorphism as adults. We investigated morphological differences among male and female pups using a cross-sectional sampling design to evaluate whether pup growth rates were sex-specific during the breeding season. We characterized growth rates using mass, length, and girth and found that length was the least variable measure of body growth (based on the coefficients of variation for the 3 measures of body size). Male pups were heavier on average than female pups on any given day of sampling but did not grow faster than females. No significant differences were noted in the body conditions of male and female pups. These findings suggest that the sexual differences among pups of A. philippii originate before birth and are not accentuated while suckling during the breeding season.

Cold environments are challenging for small endotherms because they must increase heat production to compensate for increased heat loss to the environment. Mammals that endure cold without entering torpor may have thicker fur and a lower body temperature (T_b) than those in warm environments to save energy. Activity levels also may be reduced in the cold. We aimed to determine whether activity level, exposure to chronic cold, or an interaction between the 2 could reduce the T_b of an endotherm. Wild bush rats (Rattus fuscipes) were brought into captivity and acclimated to cold (12°C) or warm (22°C) ambient temperatures and were either sedentary or exercised. Daily exercise increased maximum T_b in cold-acclimated bush rats but also decreased minimum T_b. Mean (±SE) daily T_b was significantly lower in cold-acclimated bush rats (sedentary: 36.5°C ± 0.1°C; exercised: 36.4°C ± 0.2°C) compared to warm-acclimated bush rats (sedentary: 37.3°C ± 0.2°C; exercised: 37.0°C ± 0.1°C). Body temperature decreased significantly over the time of cold acclimation. Thicker fur and lower T_bs in cold-acclimated bush rats conferred an energy saving equivalent to 11% of daily food intake in exercised rats and 22% of daily food intake in sedentary rats. The lower T_bs recorded in some small mammals in winter are not necessarily due to lower levels of activity but can result from a regulated reduction in T_b in response to cooler ambient temperatures.

Bright moonlight is thought to increase predation risk for nocturnal rodents and consequently reduce their activity levels and capture rates. We examined the effect of moonlight on the foraging activity and capture success of the federally endangered giant kangaroo rat (Dipodomys ingens) in the Carrizo Plain National Monument, California. D. ingens is adapted to open grasslands, a habitat type where moonlight should strongly influence its visibility to predators. Using a trapping data set of 11,353 captures from 2007 to 2009 and accounting for factors such as cloud cover, temperature, abundance of the San Joaquin kit fox (Vulpes macrotis mutica), plant biomass, trap acclimation, and trap effort, we found a consistently positive effect of moonlight on capture success. In foraging trials we detected no effect of moonlight on giving-up densities or time spent at seed piles. Our results suggest that giant kangaroo rats do not perceive a higher risk of predation in bright moonlight. Nocturnal rodents that rely on early visual detection of predators might benefit from moonlight as much as their predators do, thus resulting in no net change in predation risk.

An understanding of activity patterns of wildlife in relation to abiotic and biotic factors enables biologists to better understand the ecology of species, manage resources, standardize survey methods, and serve as an index of the relative density of a species. River otters (Lontra canadensis) were radiotracked between June 2002 and October 2003. Using radiotracking data, we conducted exploratory analyses to determine relative influence of abiotic and biotic factors on 2 measures of activity of otters. Abiotic factors included air temperature, barometric pressure, lunar phase, biological season, and time of day; the biotic factor was sex. Activity was measured indirectly via movement rates and directly as the proportion of location attempts recorded as active (PLA). Movement rate was defined as the distance traveled by an otter between consecutive location estimates. Generalized linear mixed models were used to explore the influence of covariates on both measures of otter activity. The model best explaining variation in movement rate included biological season, sex, a season*sex interaction, and time of day. Males moved at greater rates than females during breeding and winter seasons but moved at similar rates to females during summer. Covariates found to account for most variation in the PLA of otters included time of day, season, and temperature. Otters were active throughout the day but with bimodal peaks in the PLA during late evening and early morning hours. The PLA of otters was highest during breeding season, lowest during winter, and intermediate in summer months. In addition, the PLA of otters decreased slightly with increasing temperature. Overall, the PLA of otters in our study area was influenced by abiotic factors, and movement rates of otters were influenced by abiotic and biotic factors.

Marking behaviors of jaguars (Panthera onca) and pumas (Puma concolor) were investigated by linking sign from transect surveys to species, sex, and individual detected by camera traps along trails in the Cockscomb Basin Wildlife Sanctuary, Belize. The most commonly encountered big-cat signs were scrape marks. These were produced by cats raking the ground with their feet. Scrapes were associated more strongly with presence of male pumas than with female pumas or jaguars of either sex. Scats found in scrapes were genotyped to species level and indicated that jaguars produced larger scrapes than pumas and that pumas were more likely to scrape with their hind feet than with front feet. Scrapes were spatially clustered along trails, indicating that individuals scrape in response to other scrapes in the same area. High scraping frequencies were not associated with the presence of specific individuals, suggesting that scrape-marking behavior does not signal dominance in this area.

Space use frequently differs between sexes and may reflect differences in parental investment and limiting resources. We examined Arizona gray squirrels (Sciurus arizonensis) from April 2007 to December 2008 to determine effects of mating strategy on patterns of home-range size and overlap. Home ranges were large compared to those of congeners, suggesting an environment with low availability and predictability of resources, and differed by sex and season. Females maintained smaller home ranges overlapped more by males than females; overlap by male home ranges increased during the breeding season. Males had larger home ranges that overlapped females more than males; home-range size and overlap of both sexes increased during the breeding season. Additionally, male Arizona gray squirrels appear to respond to the distribution of females by enlarging home ranges to maximize proportion of females overlapped. Consequently, Arizona gray squirrels conform to theoretical predictions, with female space use influenced by access to food and male space use influenced by access to mates.

Townsend's big-eared bat (Corynorhinus townsendii) is a North American bat that hibernates in caves and mines. These underground habitats also are important roost sites during fall swarming, a period during which bats undergo preparation for hibernation. During swarming bats are very active at night, rousing frequently several times a night to fly within and between roosts. During hibernation nighttime activity is suppressed so that bats rouse and move infrequently. Daytime activity is suppressed during both periods by daily torpor. Both hibernacula and swarming roosts have particular thermal requirements associated with energetic optimization. Swarming roosts tend to have a higher minimum temperature than hibernacula, facilitating efficient arousal from torpor. Both roost types have low maximum temperatures, facilitating conservation of stored body fat resources. We explored and tested preferences of C. townsendii for microclimates in these habitats. Our results confirm that C. townsendii prefers habitats that are thermally constrained such that temperatures and related microclimate variables are optimum for swarming or hibernation activities.

Arctic ground squirrels (Spermophilus parryii) are abundant, colonial, noncyclical small mammals whose within-range distribution patterns have received little scientific attention. The distribution of arctic ground squirrels may drive the abundance and spatial arrangement of other arctic ecosystem components, because they serve as a prey item, plant predator, and ecological engineer. We modeled ground squirrel habitat selection using exponential resource selection functions. To determine whether the presence of adjacent squirrel burrows influenced our indices of habitat selection, we evaluated autocovariates in our models that accounted for the predicted relative probability of ground squirrel presence within neighborhoods of various sizes around each focal area. Our models demonstrated selection by ground squirrels for well-drained substrates and sloped or convex terrain, and against wet and hummocky terrain and areas of high greenness. At a large spatial scale highly selected habitat was predicted to be more limited spatially in treed areas than in tundra. Evaluation of models incorporating autocovariates demonstrated that ground squirrel distribution was not determined by the presence of other burrows. Given observed patterns of habitat selection, climate change and attendant changes to vegetation and soils could impact the ecology of arctic ground squirrels, with consequent effects on arctic plant communities and predator–prey cycles.

Seed caching by desert rodents in the family Heteromyidae is an important behavioral adaptation for animals living in environments with limited and unpredictable food resources. Heteromyids cache seeds throughout their home ranges, either concentrated in 1 location (larder hoard) or in multiple, small seed piles (scatter hoards). To minimize cache pilferage by other rodents, coexisting species may scatter hoard seeds in distinct microhabitats. We examined interspecific differences in caching and pilfering behaviors of 3 coexisting heteromyid rodents, Merriam's kangaroo rat (Dipodomys merriami), the pale kangaroo mouse (Microdipodops pallidus), and the little pocket mouse (Perognathus longimembris), to determine if caching microhabitat affects likelihood of pilferage. In outdoor enclosures we tracked cache placement and measured pilferage of artificial caches using radiolabeled Indian ricegrass (Achnatherum hymenoides) seeds. M. pallidus and P. longimembris placed seed caches mostly under shrubs, whereas D. merriami placed caches predominately in open microhabitat. However, D. merriami showed a significant preference for pilfering caches under shrubs, whereas P. longimembris did not show a significant preference for pilfering caches in either open or undershrub microhabitats. The 2 species pilfered similar numbers of caches. Coexisting heteroymid rodent species may contribute to spatial heterogeneity of available resources by caching in different microhabitats, thereby reducing but not eliminating cache pilferage by other species.

We documented the relative grain at which Canada lynx (Lynx canadensis) perceive habitat heterogeneity using fractal dimension of foraging paths. We evaluated whether lynx expended greater foraging effort (i.e., greater fractal dimension of movement paths) in patches with the highest density of snowshoe hares (Lepus americanus), or in patches with intermediate densities of prey where lower stem densities and greater visibility promote increased mobility and access to prey. Lynx foraged within patches with intermediate to high hare density and intermediate cover for hares, and thus, attempted to maximize access to prey rather than exposure to habitats with highest prey density but optimal escape cover. Fractal dimension of movement paths was greater within preferred than in nonpreferred habitats and corresponded with higher foraging success in preferred habitats. Movement paths were more tortuous at broader than finer scales, suggesting that lynx were exhibiting stronger coarse-grained than fine-grained habitat preferences. Higher fractal dimension of movement paths reduced the number of transitions between patches of higher and lower foraging quality, resulting in individual movement patterns matching the scale of interpatch variation in hare abundance and accessibility within home ranges. Lynx made their strongest foraging decisions when exhibiting higher-order resource selection, so focusing conservation efforts to alter within-patch structure may be less effective than creating patch- and landscape-scale conditions that enhance foraging success. Coarse-grained resource selection by wide-ranging carnivores may reduce the importance of fine-scale conservation efforts and emphasizes the importance of focusing conservation for these coarse-grained species on factors influencing home-range quality and maintenance of viable landscapes.

Predation risk from lions (Panthera leo) has been linked to habitat characteristics and availability and traits of prey. We separated the effects of vegetation density and the presence of drinking water by analyzing locations of lion kills in relation to rivers with dense vegetation, which offer good lion stalking opportunities, and artificial water points with low vegetation density. The spatial distribution of lion kills was studied at the Klaserie Private Nature Reserve, South Africa. The distance between 215 lion kills and the nearest water source was analyzed using generalized linear models. Lions selected medium-sized prey species. Lion kills were closer to rivers and to artificial water points than expected by random distribution of the kills. Water that attracted prey, and not the vegetation density in riverine areas, increased predation risk, with kills of buffalo (Syncerus caffer), kudu (Tragelaphus strepsiceros), and wildebeest (Connochaetes taurinus) as water-dependent prey species. Traits of prey species, including feeding type (food habits), digestion type (ruminant or nonruminant), or body size, did not explain locations of lion kills, and no seasonal patterns in lion kills were apparent. We argue that the cascading impact of lions on local mammal assemblages is spatially heterogeneous.

Predicting species distributions is increasingly important in conservation biology and, in the context of contemporary climate change, can be particularly informative for populations at the periphery of the range. Peripheral populations can exhibit unique patterns of habitat use in response to marginal conditions and can provide colonists adapted to novel or extreme environments. We conducted surveys for American pikas (Ochotona princeps) during 2007–2009 in 144 sites in Craters of the Moon National Monument and Preserve, Idaho. This species appears vulnerable to global climate change, and Craters of the Moon is an extensive area of low-elevation lava habitat situated on an interior edge of the species' range. We found pikas to be readily detectable when both direct and indirect sign were used. An estimate of detection probability from a subset of 72 sites that were visited twice was 0.92. We detected pikas in 31% of survey sites overall but only at sites above 1,605 m. We used logistic regression to model the distribution of pikas as a function of elevation, substrate, and vegetation cover. Pikas were most likely to occur on structurally complex pahoehoe lava flows above 1,600 m. The odds of pika occurrence on pahoehoe lava was >10 times that of aa lava flows and increased by 2 times for each SD increase in elevation. Pikas were also more likely to occur on lava flow sites with higher structural complexity and forb cover. An area of pahoehoe lava encompassing >250 km² in the northern portion of Craters of the Moon contained 91% of pika detections and all predicted site-occurrence probabilities >0.38, an optimal cutoff value determined by examining model receiver operating characteristic curves. Craters of the Moon may provide long-term refugia for the species, given the extent of lava habitat there. However, the importance of elevation in our models suggests that accelerated climate change could erode suitable pika habitat in the park. Most research on pikas has relied on censuses or nonrandom convenience surveys, but we demonstrate an efficient probabilistic sampling approach that has broad application for pika monitoring and research.