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Many global wildlife populations are experiencing unprecedented declines. Estimates of population abundance are needed to effectively manage common species and to conserve vulnerable species. Camera traps have advanced as wildlife monitoring tools for ungulates and can provide improved methods of estimating population abundance. Little is known, however, about how camera traps set for ungulates compare with traditional methods (e.g., ground and aerial surveys) used simultaneously. From 2012 to 2014, we captured and radio collared 34 female and 32 male bighorn sheep (Ovis canadensis) in a closed population in Utah, USA. Each collar had a unique letter and number combination. We then estimated number of young, females and yearlings, males and population abundance using multiple methods simultaneously: helicopter surveys, resight surveys performed from the ground, camera trap surveys using marked but not individually identifiable individuals and camera trap surveys using marked and individually identifiable animals. All methods estimated similar abundance. Across years, ages and sexes, however, camera trap surveys produced the most consistent and precise estimates of abundance for adult females and yearlings, lambs and the population. That method was less intrusive and safer than helicopter surveys. Our results indicate that camera trap surveys using photographs of marked animals in which the majority of the population visits a specific resource can produce precise estimates of abundance that are safer, as well as less intrusive and expensive than traditional methods. Using camera traps also creates a permanent record of photographs that can be archived and reanalyzed to answer future ecological and population questions. Finally, this method of estimating abundance can be used in other areas with ungulates that congregate around resources (e.g., watering sites or mineral licks).

Ungulates exhibit diverse mating systems that range from monogamous pair territories to highly polygynous leks. We review mating systems and behaviors across ungulates and offer a new approach synthesizing how interacting factors may shape those mating systems. Variability exists in mating systems among and within species of ungulates and likely is affected by predation risk, availability of resources (food and mates), habitat structure, and sociality. Ungulate mating systems may be labile as a consequence of the varying strength of those interacting factors. In addition, degree of polygyny and sexual dimorphism in size are associated with the evolution of mating systems. Neither male–male combat nor paternal care, however, can completely explain differences in sexual size dimorphism for ungulates, a necessary component in understanding the development of some mating systems. Whatever the evolutionary pathway, sexual segregation limits paternal care allowing more intense male–male competition. Selection of habitat structure, because it modifies risk of predation, is a major determinant of sociality for ungulates. Likewise, ruggedness and steepness of terrain limit the types of mating systems that can occur because of limitations in group size and cohesiveness, as well as the ability of males to herd even small groups of females effectively. The quality and defensibility of resources affect mating systems, as does the defensibility of females. Population density of females also may be a critical determinant of the types of mating systems that develop. Size of groups likewise constrains the types of mating tactics that males can employ. Our aim was to use those relationships to create a broad conceptual model that predicts how various environmental and social factors interact to structure mating systems in ungulates. This model provides a useful framework for future tests of the roles of both ecological and social conditions in influencing the social systems of ungulates., We provide a new approach to understanding mating systems in ungulates. We integrate both social and environmental factors in doing so. We develop a predictive model to help understand the evolution of these unique behaviors, which should help to direct future studies.

Understanding frequency and variation of cave-exiting activity after arousal from torpor of hibernating bats is important for bat ecology and conservation, especially considering white-nose syndrome. In winter from 2011 to 2018, we acoustically monitored, and counted in hibernacula, two species of conservation concern—western small-footed myotis (Myotis ciliolabrum) and Townsend’s big-eared bats (Corynorhinus townsendii)—in 9 caves located in important habitat for these species in western North America. We investigated if cave-exiting activity differed by species, cave, number of hibernating bats, moon phase, and weather variables. Both species exited hibernacula during all winter months, but most activity occurred in March followed by November. Although we counted almost 15 times more Townsend’s big-eared bats during hibernacula surveys, we documented western small-footed myotis exiting caves 3 times more than Townsend’s big-eared bats. Cave-exiting activity increased with increasing number of hibernating bats, but more so for western small-footed myotis. Both species of bats were active during warm weather and low wind speeds. Western small-footed myotis were more active during colder temperatures, higher wind speeds, and greater change in barometric pressure than Townsend’s big-eared bats. Our results provide a long-term dataset of cave-exiting activity after arousal from torpor during hibernation for these species before the arrival of white-nose syndrome.

Timing of births in ungulates is influenced by ecological factors, and differences in seasonality of births have evolutionary implications for these mammals. Birthing habitat is one of the most important home-range attributes for ungulates, and disturbances during this time can decrease survival of young and population growth. We calculated timing of births and quantified habitat selected by nursery groups (i.e., females with young) of desert bighorn sheep (Ovis canadensis nelsoni) to produce and project a geographic information system (GIS) model of lambing period habitat (i.e., birthing locations and areas used up to 6 weeks post-parturition) in southeastern Utah, United States. We then applied that model to identify suitable lambing period habitat in an adjacent area for a population of Rocky Mountain bighorn sheep (O. c. canadensis). We monitored 19 global positioning system (GPS) collared females from 2012 to 2013 to delineate the birthing season. We used GPS locations during that time and logistic regression within a model-selection framework to differentiate between lambing period habitat and random locations based on habitat and anthropogenic covariates. We used model coefficients to produce and project a GIS model of lambing period habitat. Across both years, 89% of 45 births occurred in May (range = April 27–June 9). We quantified covariate values at 750 lambing period and 750 random locations during that time in the San Rafael study area. The top model included elevation, slope, terrain ruggedness, aspect, existing vegetation type, and distance to trails and roads. Those variables predicted lambing period habitat for desert bighorn sheep (rho = 0.99, P = 0.02). We then overlaid that model on 1,130 GPS locations from 17 female Rocky Mountain bighorns in the Green River study area. In both areas, a mean of 71% of locations were in the top two (of five) probability categories (San Rafael high = 37%, medium high = 31%; Green River high = 50%, medium high = 23%). Females in lambing period habitat preferred steep, north-facing slopes, rugged terrain, low elevation, and avoided roads. Our GIS model projected areas of lambing period habitat for adjacent desert and Rocky Mountain bighorns and provided land managers with a map of habitat in areas where resource extraction and recreation are increasing. Identifying timing of parturition, and high-probability lambing period habitat, will help managers mitigate temporal and spatial conflicts between bighorn sheep and anthropogenic activities. Similar data regarding timing of births and a GIS model can be applied to conserve habitat for other ungulates also.

Bat populations are being impacted by many threats, including white-nose syndrome, wind energy development, and hibernaculum disturbance and modification. Understanding the use of caves as hibernacula by bats in the western United States is necessary for the conservation and management of these mammals and their habitat, as well as for monitoring the arrival of white-nose syndrome. We identified biologically important hibernacula from 304 winter surveys (1 November–31 March) in 64 caves from 1984 to 2016 in southern Idaho, USA. During surveys researchers counted 37,693 bats representing 6 species. Townsend's big-eared bats (Corynorhinus townsendii townsendii) comprised 96.1% (36,237 individuals in 58 caves) and western small-footed myotis (Myotis ciliolabrum ssp.) comprised 3.8% (1432 individuals in 22 caves). Thirty of the 64 caves were biologically important for Townsend's bigeared bats (maximum count ≥20 individuals), and the largest hibernating colony of that species occupied cave C34 (8 surveys, = 1610 individuals, SD 415, range 962–1994). Thirteen caves were biologically important hibernacula for western small-footed myotis (maximum count ≥5 individuals), and the largest hibernating colony of that species occupied cave C24 (6 surveys, = 98 individuals, SD 53, range 32–152). Ten caves were biologically important hibernacula for both species. Our results indicate that Townsend's big-eared bats are the predominant species that hibernate on the Snake River Plain in southern Idaho, and that this area has a high density of hibernacula—and the largest reported hibernaculum—for Townsend's big-eared bats and western small-footed myotis in western North America. We recommend that biologists prioritize monitoring the 13 biologically important hibernacula of western small-footed myotis as well as the 10 caves used by both species for the potential arrival of white-nose syndrome in this area and to track the abundance of Townsend's big-eared bats. Our results will help biologists with the management and conservation of bats and their habitat as well as aid in land use planning in this area.

Monitoring dispersal, habitat use, and social mixing of released ungulates is crucial for successful translocation and species conservation. We monitored 127 female bighorn sheep (Ovis canadensis) released in three populations from 2000 to 2009 to investigate if augmented bighorns expanded and shifted seasonal ranges, used different habitat compared with resident females, and if animals mixed socially. Augmented bighorns in all populations expanded range use compared with residents by shifting utilization distributions. Size of utilization distributions, however, were smaller for augmented females compared with residents in all areas except one. Overlap of seasonal utilization distributions between augmented and resident bighorns and use of slope and elevation differed across populations. In two populations, differences in size and overlap of seasonal utilization distributions and use of slope and elevation supported the hypothesis that habitat use of bighorns in their source area influenced their habitat use after release. Mixing between resident and augmented adult females occurred on average during only 21% of sightings and was similar across populations. Our results clarify how augmented bighorns mix with resident animals and how habitat use is modified following augmentations. Such information is needed to improve bighorn sheep augmentations and can be applied to augmentations of other ungulates.

Bats are being impacted by many threats (e.g., human disturbance of maternity roost sites and white-nose syndrome). Bat maternity roosts are a limited resource, and bats exhibit strong fidelity to these sites; therefore, identifying these features and conserving the surrounding habitat are important for bat management. Southern Idaho consists of the largest, contiguous volcanic pseudokarst area in the U.S., which provides important cave habitat for bats, but little is known about bat maternity roosts in this area. We compiled data spanning 36 years in southern Idaho to identify caves used by maternity colonies. From June 1980 to August 2016, researchers surveyed 313 caves. We documented 11 caves used by maternity colonies of Townsend's big-eared bats (Corynorhinus townsendii), and 10 caves that were potentially used by maternity colonies. In the 11 caves used as maternity roosts, the median number of Townsend's big-eared bats was 38, and the mean number was 49 individuals (SD = 47.1, range = 8 to 160 bats). Our data highlight southern Idaho as an important maternity roosting area for bats in Idaho and western North America, and provide baseline information of maternity caves prior to the arrival of white-nose syndrome, which can help managers during land-use planning in this area.

Estimating abundance or distribution of species that are scarce or difficult to detect is challenging for wildlife biologists. Pygmy rabbits (Brachylagus idahoensis) are secretive, sagebrush (Artemisia spp.) obligates of conservation concern that occupy the Intermountain West, USA. These unique leporids are difficult to monitor; however using remote cameras in conjunction with ranking of burrow activity may help refine sampling techniques for these mammals. We classified and deployed remote cameras at 405 burrows of pygmy rabbits between 2006 and 2010 in six study areas across Utah, USA. We ranked burrows based on the appearance of fecal pellets, as well as the condition of burrow entrances. We also documented the presence of pygmy rabbits and potential competitors and predators of pygmy rabbits at burrows using remote cameras. We used mixed-effects, zero-inflated negative binomial models and AIC model selection to evaluate the relative influences of burrow activity ranking, season, and rate of photographs for potential competitors and predators of pygmy rabbits on photo rates of pygmy rabbits. The top 2 models supported a simplified (active or inactive) burrow classification system and accounted for 45% of AIC weight. Rates of pygmy rabbit photographs were further influenced by meters from habitat edge (β = 0.0008 ± 0.0004, 95% CI = 7.07E-05–0.002), photo rate of cottontail rabbits (β = 0.31 ± 0.11, 95% CI = 0.08–0.53), and were higher during summer than other times of the year (β = 0.38 ± 0.19, 95% CI = 0.01–0.74). Mean number of days to detection of pygmy rabbits at burrow complexes classified as active was four (SE = 0.61), and a two-week sampling period was needed to capture 81% of first detections. Our results refine commonly used ranking criteria of burrow complexes to a 2-level scale (active and inactive), and also emphasize the use of remote cameras as an effective technique for quantifying activity of pygmy rabbits at burrow complexes. Such information can help researchers and land managers more effectively survey this species for conservation and management efforts.

Abstract ContextWildlife biologists accumulate large quantities of images from remote cameras, which can be time- and cost-prohibitive to archive and analyse. Remote-camera projects would benefit from not setting cameras longer than needed and not analysing more images than needed; however, there is a lack of information about optimal deployment time required for remote-camera surveys to estimate ungulate abundance. AimsThe objective was to estimate abundance of adult females in a population of Rocky Mountain bighorn sheep (Ovis canadensis canadensis) in Utah, USA, from 2012 to 2014, and determine whether this type of study can be conducted more efficiently. Because females are the most important cohort for population growth, remote cameras were set at three water sources and mark–resight models in Program MARK were used. MethodsWe compared estimated abundance of collared and uncollared females by number of days cameras were set using 31 replicated abundance estimates from each year starting 1 July. Each replicated estimate used a different number of days and photographs from a 62-day sampling period (1 July to 31 August). Key resultsAbundance estimates ranged from 44 to 98 animals. Precise estimates of abundance, however, were obtained with only 12 days of sampling in each year. By analysing only 12 days of images rather than 62 days in all years, the estimated mean of 58 adult females would have changed by only 7 individuals (±4 individuals, range=3–10 animals), the s.e. would have increased by a mean of only 4 individuals (±1.6, range=2.0–5.2 individuals) and a mean of only 18% (±10.5%, range=8–29%) of images would have been analysed. Across the study, analysis of >23000 (>80%) images could have been avoided, saving time and money. ConclusionsThe results indicate that an asymptotic relationship exists between estimated abundance of female bighorn sheep and remote-camera deployment time. ImplicationsThe mark–resight methods used in the present study would work for other ungulates in which individuals are radio collared or marked using remote cameras set at water sources, trail crossings or mineral licks. These findings can help researchers reduce cost of setting, servicing, archiving and analysing photographs from remote cameras for ungulate population monitoring.

Bighorn sheep (Ovis canadensis) often die from respiratory disease after commingling with domestic sheep. From 2000 to 2009, we observed commingling between domestic and reintroduced bighorn sheep in 3 populations in UT, USA. We investigated how commingling affected survival of radio-collared female bighorns that were released initially (founder) and those that were subsequently released (augmented). We predicted that the proportion of young surviving to their first winter and population growth would be lower after observed commingling with domestic sheep. We observed groups of bighorns year-round on 2,712 occasions and commingling between domestic sheep and bighorns in 6 instances. On Mount Timpanogos, survival rates were best modeled as constant for females (n = 57) before and after observed commingling with domestic sheep. Survival rates of female bighorns, however, decreased significantly in Rock Canyon (n = 21) and on Mount Nebo (n = 22) for founder, but not augmented bighorns after observed commingling with domestic sheep. Also, the proportion of young surviving to their first winter was almost 3 times lower and population growth was reduced for bighorns after observed commingling with domestic sheep in Rock Canyon and on Mount Nebo. Commingling between domestic and bighorn sheep reduced population parameters in 2 of 3 bighorn populations we studied; however, on Mount Timpanogos, interactions between those 2 species were not fatal for radio-collared female bighorns. Wildlife biologists should manage for spatial separation of these 2 species and consider the location of hobby farms and trailing operations of domestic sheep near release sites for bighorns.

Abstract ContextTranslocation of wildlife has become common practice for wildlife managers charged with management of animals on increasingly modified landscapes. Mule deer (Odocoileus hemionus) is a species of great interest to the public in western North America, and individuals of this species have been translocated several times, but little has been done to document the outcomes of those translocations. AimOur objective was to evaluate the movement, space use and site fidelity of translocated female mule deer in comparison with resident female deer in Utah, USA. MethodsIn January and March 2013, 102 translocated and 50 resident female mule deer were captured and fitted with radio-transmitters. Movement distances, home range sizes and seasonal range sizes were compared, as well as site fidelity between translocated and resident deer. Key resultsMean distance moved and mean annual home range size were significantly larger for translocated than resident deer in 2013, but not in 2014. Translocated deer demonstrated high site fidelity to their release areas. In total, 75% of surviving deer returned during the fall (September–November) migration to winter range within 7km of release sites. ConclusionsOur results indicate that home range sizes and movements of translocated deer are larger than those of resident deer during the first year after release, but during the second year after release, home range sizes and movements of translocated deer are similar to those of resident deer. ImplicationsThe similar home range sizes and movements of translocated and resident deer >1 year after release, as well as the high site fidelity we observed, suggests that translocation is a strategy managers could use to establish or augment populations of mule deer on winter range.

Timing (mean birth date) and synchrony (variance around that date) of births can influence survival of young and population growth in ungulates. We quantified timing and synchrony of births in 2 populations of bighorn sheep (Ovis canadensis) that were acquired from different source herds and reintroduced to adjacent areas. From 2001 to 2007 we recorded 121 birth dates to test whether timing and synchrony of parturition were similar between populations. Furthermore, we calculated population-wide survival of young to their 1st winter. Females on Mount Timpanogos gave birth later than females inhabiting Rock Canyon from 2001 to 2002 and in 2004; those females gave birth earlier in 2007 than females inhabiting Rock Canyon. Timing of births was similar in 2003 and from 2005 to 2006. The relationship between differences in mean birth dates between populations and time since reintroduction was marginally nonsignificant (P 5 0.075), whereas differences in synchrony of births were negatively related to time since reintroduction (P 5 0.005). Survivorship of young was higher for females in Rock Canyon that gave birth on average 30 days earlier from 2001 to 2002 and during 2004 than for females on Mount Timpanogos during those years. Our findings provide evidence that within 5 years after reintroduction bighorn sheep adjusted timing and synchrony of parturition to environmental conditions of their release site. A slow adjustment of these life-history characteristics by females on Mount Timpanogos possibly contributed to lower survival of young to their 1st winter during 2001–2002 and 2004, which could have impeded establishment of those mammals in that study area.

Sagebrush (Artemisia spp.) communities are ecologically critical; however, these areas currently face severe threats from alteration and reduction. Pygmy rabbits Brachylagus idahoensis are sagebrush specialists that occupy the intermountain region of the USA. Little is known concerning how fragmentation of sagebrush and an increase in habitat edge may impact pygmy rabbits. From 2004 to 2009 in Utah, USA, we tested hypotheses concerning the influences of habitat edge on pygmy rabbits. We quantified the number of active pygmy rabbit burrows in relation to distance from habitat edge. At differing distances from habitat edge, we also deployed remote cameras at burrows and counted fecal pellets to document potential increases in the number of terrestrial predators and competitors. We classified activity of 528 burrows (284 active and 244 inactive). The proportion of active burrows was lower within 100 m of habitat edge (r2=0.502, P=0.02) compared with burrows located in control areas (>100 m from habitat edge). Photographs of pygmy rabbits decreased at burrows closer to habitat edge (P

Males and females of most dimorphic ruminants segregate outside the mating season, which may necessitate that conservation efforts focus on differential resources used by the sexes. Dimorphic bighorn sheep Ovis canadensis are one of the rarest ungulates in North America with some populations listed as endangered. Water sources are important for the persistence of populations of bighorns, especially in a changing climate. Understanding whether the sexes use different water sources could influence the conservation of this species and the habitats they occupy; however, little research exists regarding this important topic. We tested hypotheses relating to use of water sources by reintroduced male and female bighorns in Utah, USA. We investigated whether use of this resource differed across seasons by sex, and if sexes used water more during drought compared with non-drought conditions. Bighorns used small, adjacent core areas during segregation, and males and females used different sources of water during that time. Males visited water sources used by females more during aggregation. Males and females used water sources more in summer, and males visited water sources more during rut than did females. Males and females did not use water sources more during drought compared with non-drought conditions; however, sexes visited water sources more during the season following drought than following non-drought conditions, indicating a time-lag in use of this resource. Our results highlight the importance of water sources used by sexes of bighorns, and indicate that the existing criterion for distance of bighorn reintroductions from water may be inadequate for successful establishment of populations. We recommend conservationists assess availability of water sources near habitat used by male and female ungulates before conserving and manipulating habitat, siting artificial sources of water and reintroducing animals.

Little is known regarding the potential adjustment of maternal care towards late-born young by reintroduced female ungulates, which may be adapted to environments quite different than those at their release site. We compared nursing behaviors of young to investigate whether females would adjust maternal care toward late-born young between two populations of reintroduced bighorn sheep (Ovis canadensis) in Utah, USA. Neonates on Mount Timpanogos were born on average 28 days later in 2002 and 13 days later in 2003 than neonates in Rock Canyon. Suckling and weaning behaviors, however, were similar in 2002 and 2003 between those populations, except for the number of unsuccessful suckles, which was greater for young in Rock Canyon than for young on Mount Timpanogos during the middle of lactation in 2002. Our results provide preliminary evidence that females did not adjust maternal care to compensate for late-born young within the first 3 years following reintroduction, which possibly influenced survivorship of young.

Water sources are an important habitat component for populations of bighorn sheep (Ovis canadensis), and the technique of sampling at water sources has been used extensively to study behaviors and estimate parameters of bighorn populations, Little is known, however, concerning the time of day at which groups of bighorns visit water. Understanding when bighorns visit water sources will allow wildlife investigators to conduct sampling when bighorns are most likely to be present at this resource. We quantified use of 7 water sources by reintroduced bighorn sheep during summer 2005 and 2006 on Antelope Island State Park, Utah. Our purpose was to determine if female, male, or mixed-sex groups visited water at a particular time and if visits to this resource by all bighorns differed in time during drought conditions compared with nondrought conditions. The mean time that all bighorns visited water was 14:22 (s = 3:08 hours). No time differences existed among female, male, or mixed-sex groups or betwee...

Water sources are important for the conservation and management of bighorn sheepOvis canadensis (Shaw, 1804). Little is known, however, regarding the use of water by reintroduced Rocky Mountain bighornsO. c. canadensis (Shaw, 1804). Our purpose was to quantify use of water sources by bighorns to test hypotheses related to the value of these sites on Antelope Island, Utah, USA, from July 2005 to December 2006. We predicted that bighorns would increase the number and duration of visits to water during summer. Moreover, we predicted that animals would visit and spend more time at water during drought. Our results indicate that bighorns visited and spent more time around water in summer. These animals, however, did not visit and spend more time at water during drought. Nevertheless, use of water sources increased during times of similar precipitation that followed drought, indicating a potential time-lag in water use by bighorns. Our results underscore the importance of water for reintroduced bighorns in the deserts of western USA, and indicate that animals congregate in riparian areas near water and thereby may facilitate the spreading of diseases and parasites.

Mating by young males or low male-to-female ratios can decrease pregnancy rates and postpone birthdates in ungulates, thereby hindering population growth. Young (2.5‐3.5 yr old) male bighorn (Ovis canadensis) behave differently than older males, and age, horn size, mating behavior, and social rank help determine reproductive success. We estimated birthdates in two populations of bighorn sheep in Utah, USA, to determine if mating by young males or low male-to-female ratios resulted in fewer young born per female, a shift in mean timing of births, or asynchronous births. When reintroduced, the Rock Canyon population consisted of four males (two each of 2.5 yr old and 1.5 yr old) and a 1 to 7.5 ratio of males (>2 yr old) to adult females (‡3.5 yr old); the Mount Nebo population consisted of four males £1.5 yr old and a 0 to 12 ratio of males to adult females. For both populations, the number of young born per female did not differ between the first parturition period after reintroduction (where females were impregnated by males from their source populations) and the second period of parturition (where females were impregnated by young, reintroduced males). Mean birthdates and synchrony (SD) of births did not differ for Rock

We studied group size, composition, and mating activities in American bison (Bison bison) during rut on the Delta Junction Bison Range in interior Alaska, USA, in 1996 and 1997. Our purpose was to determine the effects of large males (‡5 yr old) on mating and associated activities. Groups with large males were larger than those containing smaller males. Most groups of bison were mixed-sex (90%), but large males occurred in only one-half of all groups. Moreover, females in groups with large males were more likely to copulate than those in groups with smaller males, indicating a female preference for large males. Nevertheless, our results are consistent with large males seeking out adult females for mating rather than vice versa. Mating peaked in mid-August during both the study years and was highly synchronous. Scent marking was coincident with mating, an outcome consistent with a hypothesis of such behavior triggering ovulation. Scent marking by large male bison occurred in both male‐male and male‐female contexts, but was associated most often with sexual activities. No differences in group size occurred with changes in weather or among vegetation types occupied by bison. Group size of bison, however, was larger with increasing distance from the forest edge, which likely was a response to predation risk in this predator-rich environment.

Context Human activities can affect habitat selection by ungulates during parturition. Minimising human–wildlife conflicts during the birthing period can be critical in national and state parks that receive high numbers of human visitors. American bison (Bison bison) are an iconic species in North America, and many conservation herds of bison occupy national and state parks and wildlife refuges. Aims We investigated timing of births and birth-site selection of bison on Antelope Island State Park, Utah, at multiple spatial scales to determine the relative influence of surrounding vegetation, topography and distance to anthropogenic features (i.e. trails, roads or structures) on selection of birthing habitat. Methods We used vaginal implant transmitters to determine timing of births and to identify birth sites of bison. We used logistic regression within a model-selection framework to differentiate between birth sites and random locations, based on potential explanatory variables. We then used model-averaged coefficients to produce and project a GIS model of birthing habitat onto Antelope Island. Key results During 2010 and 2011, we quantified variables surrounding 35 birth sites and 101 random sites. Variables in top models of birth-site selection for bison included landscape curvature and elevation, averaged at a 500-m radius around birth sites, as well as distance to nearest trails, roads or structures. Five-fold cross validation (rho = 0.89; P

Context Little is known about the consequences of sexual segregation (differential use of resources by the sexes outside of the mating season) for the conservation of large mammals. Roadways (i.e. the strip of land over which a road or route passes) are ubiquitous around the world, and are a major cause of wildlife mortality, as well as habitat loss and fragmentation. Many populations of bighorn sheep (Ovis canadensis) occur at low densities and in a metapopulation structure. Roadways could affect movements of males and females differentially, an outcome that has not been considered previously. Aims We investigated the propensity of the sexes to cross a paved two-lane road and a single-lane, maintained dirt route and predicted that adult males, because of their life-history characteristics, would cross those roadways more often than females. Methods We investigated movements of male and female bighorn sheep from 1986 to 1990. We used a fixed-wing aircraft with an H-antenna on each wing strut to locate individuals each week from October 1986 to December 1990. We estimated the degree of overlap among 50% core areas of use by males and females with the utilisation distribution overlap index (UDOI). Key results We relocated male and female bighorn sheep on 948 occasions during sexual aggregation and on 1951 occasions during sexual segregation. More males than females were likely to cross both types of roadways during segregation, and the dirt route during aggregation. Propensity of males and females to cross roadways was strongly influenced by time of year (i.e. whether the period of sexual aggregation or sexual segregation). The lowest overlap in 50% core areas was between females and males during periods of segregation (UDOI = 0.1447). Conclusions More males than females crossed Kelbaker Road and the unnamed dirt route during segregation, as well as the unnamed route during aggregation. Both of those features could affect males more than females, and could result in reductions in the use of habitat or increased mortality of bighorn sheep from vehicle collisions as a result of spatial segregation of the sexes. Implications During environmental review, biologists should consider sexual segregation when assessing potential anthropogenic effects on movements of bighorn sheep. Biologists also should consider sexual segregation and how roadways, even lightly traveled routes, affect movements of male and female ungulates differently before manipulating habitat, translocating animals, or constructing or modifying roadways.

Context.Timing (mean birthdate) and synchrony (variance around that date) of births can influence survival of young and growth in ungulate populations. Some restored populations of ungulates may not adjust these life-history characteristics to environments of release sites until several years after release, which may influence success of reintroductions. Aims. We quantified timing and synchrony of births from 2005 to 2007 in four populations of reintroduced bighorn sheep(Oviscanadensis)occupyingtwoecoregions(CentralBasinandRangeandWasatchandUintaMountains)inUtah, USA,toinvestigatewhetherbighornswouldadjusttheselife-historycharacteristicstoenvironmentalconditionsofthetwo ecoregions. We also compared timing and synchrony of births for bighorns in their source herd (Antelope Island) with bighorns in an ecologically similar release site (Stansbury Mountains) during 2006 and 2007. Methods. We relocated female bighorns to record birthdates of young, and observed groups of collared bighorns to quantify use of elevation by those ungulates. We also calculated the initiation, rate and timing of peak green-up by ecoregion, using the normalised difference vegetation index. Key results.We quantified 274 birthdates, and although only separatedby 57km, bighorn populations occupying the Central Basin and Range Mountains gave birth an average of 29 days earlier than did those on the Wasatch and Uinta Mountains,which corresponded with the initiation of vegetation green-up.Additionally, bighorn sheep on the Stansbury Mountains (ecologically similar release site) gave birth at similar times as did bighorns on Antelope Island (source area). Conclusions.Populationsofbighornsheepthatwerereintroducedintoadjacentecoregionsadjustedtimingofbirthsto environments and green-up of vegetation in restoration areas. Timing and synchrony of births for reintroduced bighorn sheep in an ecologically similar release site were the same as those of their source area. Implications. Consideration should be given to the adjustment of timing and synchrony of births when reintroducing bighorns, especially when animals are released into different ecoregions. Also, biologists should select release sites that are ecologically similar to source areas, thereby reducing potential negative effects of animals adjusting timing and synchrony of births to environmental conditions of restoration areas. Additional keywords: birthing period, Ovis canadensis, parturition, restoration, translocation.