Influences on Release-Site Fidelity of Translocated Elk

Several eastern states are considering the restoration of free‐ranging elk populations via translocation from western populations. Optimal habitat immediately surrounding release sites has been found to enhance elk reintroduction success in western states. Little information exists, however, to aid eastern managers in identifying release sites with the highest chance of restoration success. We monitored the movements of 415 translocated elk released at three sites in southeastern Kentucky to identify landscape characteristics that enhance release‐site fidelity. The distance elk moved after release differed among sites (F_2,322 = 4.63, p = 0.01), age classes (F_2,322 = 4.37, p = 0.01), and time intervals (F_2,322 = 40.74, p < 0.001). At 6 and 12 months post‐release, adults (15.81 ± 17.32 and 16.38 ± 20.29) and yearlings (13.91 ± 16.44 and 14.61 ± 21.11) moved farther than calves (8.06 ± 14.03 and 9.37 ± 14.40). The release site with the highest fidelity was privately owned, 15% open, and had the highest amount of edge compared with the other release sites. The two remaining sites contained large amounts of expansive openland or forest cover with lower amounts of edge. Additionally, both sites were publicly owned and experienced a higher degree of human‐generated disturbance compared with the site to which elk were most faithful. When selecting release sites, managers should avoid areas dominated by a single cover type with little interspersion of other habitats. Rather, areas with high levels of open‐forest edge (approximately 5.0 km/km²) and limited‐human disturbance will likely enhance release‐site fidelity and promote restoration success.     

Patterns of Mortality and Factors Influencing Survival of a Recently Restored Elk Population in Ontario,Canada

This study examined patterns of mortality and determinants of survival among elk recently restored to four sites in Ontario, Canada (1998–2005). We predicted that: (1) elk located in release sites closer to the core of their historic range would have higher survival; (2) survival would increase as an animal's time and experience on the landscape increased; and (3) survival rates would decline as animals moved farther away from the release site. During the study, 443 elk were radiocollared and released; 218 mortalities were documented. Predation by wolves was the most important proximate cause of mortality, followed by death due to injuries from translocation and/or capture myopathy, accidents, emaciation, poaching, and Parelaphostrongylus tenuis infection. Overall, annual survival of elk across Ontario ranged from 0.45 (0.37–0.53) to 0.81 (0.66–0.90), with rates being lowest in the years immediately following release and highest in the final years of the study; this pattern was due to high initial mortality from translocation injuries and/or capture myopathy and possibly lack of familiarity with novel habitat. Model‐averaged hazards further support this finding, as the most important factor influencing elk survival was the length of holding period, with elk released after limited holding being less likely to survive than those held for longer periods. Our results suggest that mortalities caused by capture myopathy and transportation‐related injuries are important sources of risk for translocated elk. The method of introduction to the novel landscape and behavior in the first year should be accommodated via soft‐release and appropriate release areas.     

Genetic structure of California's elk: a legacy of extirpations,reintroductions, population expansions,and admixture

California, USA, is home to 3 subspecies of North American elk (Cervus canadensis): Roosevelt (C. c. roosevelti), Rocky Mountain (C. c. nelsoni), and tule (C. c. nannodes). Effective management requires a baseline understanding of each subspecies' range, admixture zones, and geographic patterns of genetic diversity. To address these questions, we genotyped 1,271 individual elk from California (n = 1,204) and reference populations of Rocky Mountain and Roosevelt elk from Nevada (n = 32) and Oregon (n = 35), USA. Using 19 polymorphic microsatellite loci, we detected admixture between Roosevelt and Rocky Mountain elk at a contact zone in northern California, and between Roosevelt and tule elk in north-coastal California and central-coastal California. We identified a genetically distinct population of Roosevelt elk in northwestern California, likely reflecting the remnant population that survived a large demographic decline from overhunting during the 1800s. Tule elk exhibited lower levels of heterozygosity (0.44 ± 0.03 [SD]) and allelic richness (2.9 ± 0.2) than Rocky Mountain (0.58 ± 0.05, 4.9 ± 0.4, respectively) and Roosevelt (0.50 ± 0.06, 4.4 ± 0.6, respectively) elk. Among tule elk populations, heterozygosity varied, with the lowest heterozygosity (0.23 ± 0.05) corresponding to the oldest enclosed herd used over the past century as a source of translocations. Among tule elk populations, genetic structure revealed several cases of successful and unsuccessful reintroduction or augmentation attempts. Results provide an essential baseline for future monitoring and decisions about harvest management, translocations to preserve genetic diversity, and landscape-level conservation planning to maintain, enhance, or obstruct connectivity of elk populations. Genome-wide sequencing and analyses are needed to quantify inbreeding absolutely and assess genetic load and the age of admixture where subspecies currently exchange genes.     

The Restoration of Elk (Cervus elaphus) in Ontario, Canada: 1998–2005

In 1997, a plan to restore Elk (Cervus elaphus) to Ontario was approved by the provincial government. The objective of the Ontario elk restoration program, a multipartnered collaboration, was to restore a species that had been extirpated from the province during the 1800s. During 1998–2001, 460 elk were acquired from Elk Island National Park, Alberta, for release in four areas of Ontario. As greater than 90% of the elk were radio collared, monitoring provided detailed information on the dynamics of the four populations. Comprehensive research projects using graduate students were implemented to determine the environmental impact of releasing elk in Ontario. Those studies are in progress or have been completed and include the effect of wolf predation on restored elk, white‐tailed deer and elk resource overlap, the development of genetic profiles for elk, and solutions for elk/human conflicts. Mortality of the released elk averaged 41% (190/460) during 1998–2004 with annual mortality generally declining over time in each release area. The primary causes of elk mortality included wolf predation (25% of mortalities), illegal shooting (13%), stress‐related emaciation (13%) (partially due to the stress of relocation), bacterial infections (7%), and collisions with vehicles (6%). Productivity has been high in one of the release areas with 24–65% of the cows being observed with calves during late winter surveys. However, productivity has been low in two of the northern release areas due to a variety of factors including wolf predation. In some areas, dispersion of elk appeared to be related to the length of time animals were kept in pens prior to release. The precalving population estimate for Ontario in March 2004 was 375–440 elk. A comprehensive program review was conducted in 2003/2004 that included recommendations relating to the future management of elk in Ontario.     

The Influence of Translocation Strategy and Management Practices on the Genetic Variability of a Reestablished Elk (Cervus elaphus) Population

Reintroduction of terrestrial vertebrates with the goal of ecosystem restoration typically establishes small and isolated populations that may experience reduced genetic variability due to founder effects and genetic drift. Understanding the genetic structure of these populations and maintaining adequate genetic diversity is important for long‐term restoration success. We quantified genetic variability at six microsatellite loci for a reintroduced population of Cervus elaphus (elk) restored to the tallgrass prairie ecosystem of northeastern Kansas. Allelic richness, observed and expected heterozygosity were intermediate to levels reported in other North American elk populations. Current levels of genetic variability in restored North American elk populations were not well explained by founding population size, number of founding populations, or number of years since the last translocation. Simulation results suggest that the retention of genetic variability in isolated populations is strongly influenced by mating system while also being impacted by temporal variability in population size and population growth rate. Our results have implications for understanding how translocation strategies and post‐reintroduction management may influence genetic variability in restored populations.     

Dynamics of Newly Established Elk Populations

Abstract: The dynamics of newly established elk (Cervus elaphus) populations can provide insights about maximum sustainable rates of reproduction, survival, and increase. However, data used to estimate rates of increase typically have been limited to counts and rarely have included complementary estimates of vital rates. Complexities of population dynamics cannot be understood without considering population processes as well as population states. We estimated pregnancy rates, survival rates, age ratios, and sex ratios for reintroduced elk at Theodore Roosevelt National Park, North Dakota, USA; combined vital rates in a population projection model; and compared model projections with observed elk numbers and population ratios. Pregnancy rates in January (early in the second trimester of pregnancy) averaged 54.1% (SE = 5.4%) for subadults and 91.0% (SE = 1.7%) for adults, and 91.6% of pregnancies resulted in recruitment at 8 months. Annual survival rates of adult females averaged 0.96 (95% CI = 0.94-0.98) with hunting included and 0.99 (95% CI = 0.97-0.99) with hunting excluded from calculations. Our fitted model explained 99.8% of past variation in population estimates and represents a useful new tool for short-term management planning. Although we found no evidence of temporal variation in vital rates, variation in population composition caused substantial variation in projected rates of increase (Λ = 1.20-1.36). Restoring documented hunter harvests and removals of elk by the National Park Service led to a potential rate of Λ = 1.26. Greater rates of increase substantiated elsewhere were within the expected range of chance variation, given our model and estimates of vital rates. Rates of increase realized by small elk populations are too variable to support inferences about habitat quality or density dependence.     

Development of a Sightability Model for Low-Density Elk Populations in Ontario,Canada

ABSTRACT The status of recolonizing elk (Cervus elaphus) populations in Ontario, Canada, is unclear and there is a need for effective population survey methods that can be applied locally. We sought to develop a sightability model that could account for both low densities of elk and dense forest cover in elk-release areas in Ontario. We corrected winter aerial survey counts for sightability based on radiocollared animals known to be within observable distance of the aircraft. The multivariate model with the highest Akaike's Information Criterion corrected for sample size weight (w_i = 0.427) revealed that elk group size, elk activity, dominant tree type, percent canopy cover, and percent conifer cover were significant predictors of elk sightability. The group-size effect indicated that odds of sighting an elk increased by 1.353 (95% CI = 0.874-3.689) for every additional elk. Standing elk were 5.033 (95% CI = 0.936-15.541) times more likely to be observed than were resting elk, and those located in conifer cover were 0.013 (95% CI = 0.001-0.278) times less likely to be sighted than elk in deciduous cover. Furthermore, elk located in >50% canopy cover and >50% conifer cover were 0.041 (95% CI = 0.003-0.619) times and 0.484 (95% CI = 0.024-9.721) times less likely to be sighted than elk in more open habitat, respectively. During model validation, observers detected 79% (113/143) of known elk in any given area, and population and sightability model predictions (±90% CI) overlapped with the population estimate, implying that our predictive model was robust. Unsurprisingly, large groups of elk in open habitat increased model precision, which highlights difficulties of counting Ontario elk in their northern range. We conclude that our model provided increased reliability for estimating elk numbers in Ontario compared to existing methods, and that the estimator may be useful in other areas where elk density is low and sightability is poor due to dense forest cover.     

Identifying Sites for Elk Restoration in Arkansas

Abstract: We used spatial data to identify potential areas for elk (Cervus elaphus) restoration in Arkansas. To assess habitat, we used locations of 239 elk groups collected from helicopter surveys in the Buffalo National River area of northwestern Arkansas, USA, from 1992 to 2002. We calculated the Mahalanobis distance (D²) statistic based on the relationship between those elk-group locations and a suite of 9 landscape variables to evaluate winter habitat in Arkansas. We tested model performance in the Buffalo National River area by comparing the D² values of pixels representing areas with and without elk pellets along 19 fixed-width transects surveyed in March 2002. Pixels with elk scat had lower D² values than pixels in which we found no pellets (logistic regression: Wald χ² = 24.37, P < 0.001), indicating that habitat characteristics were similar to those selected by the aerially surveyed elk. Our D² model indicated that the best elk habitat primarily occurred in northern and western Arkansas and was associated with areas of high landscape heterogeneity, heavy forest cover, gently sloping ridge tops and valleys, low human population density, and low road densities. To assess the potential for elk-human conflicts in Arkansas, we used the analytical hierarchy process to rank the importance of 8 criteria based on expert opinion from biologists involved in elk management. The biologists ranked availability of forage on public lands as having the strongest influence on the potential for elk-human conflict (33%), followed by human population growth rate (22%) and the amount of private land in row crops (18%). We then applied those rankings in a weighted linear summation to map the relative potential for elk-human conflict. Finally, we used white-tailed deer (Odocoileus virginianus) densities to identify areas where success of elk restoration may be hampered due to meningeal worm (Parelaphostrongylus tenuis) transmission. By combining results of the 3 spatial data layers (i.e., habitat model, elk-human conflict model, deer density), our model indicated that restoration sites located in west-central and north-central Arkansas were most favorable for reintroduction.     

Sex-Specific Elk Resource Selection during the Anthrax Risk Period

Anthrax, caused by the spore-forming bacterium Bacillus anthracis, is a zoonosis affecting animals and humans globally. In the United States, anthrax outbreaks occur in wildlife and livestock, with frequent outbreaks in native and exotic wildlife species in Texas, livestock outbreaks in the Dakotas, and sporadic mixed outbreaks in Montana. Understanding where pathogen and host habitat selection overlap is essential for anthrax management. Resource selection and habitat use of ungulates may be sex-specific and lead to differential anthrax exposure risks across the landscape for males and females. We evaluated female elk (Cervus canadensis) resource selection in the same study areas as male elk in a previous anthrax risk study to identify risk of anthrax transmission to females and compare transmission risk between females and males. We developed a generalized linear mixed-effect model to estimate resource selection for female elk in southwest Montana during the June to August anthrax transmission risk period. We then predicted habitat selection of female and male elk across the study area and compared selection with the distribution of anthrax risk to identify spatial distributions of potential anthrax exposure for the male and female elk. Female and male elk selected different resources during the anthrax risk period, which resulted in different anthrax exposure areas for females and males. The sex-specific resource selection and habitat use could infer different areas of risk for anthrax transmission, which can improve anthrax and wildlife management and have important public health and economic implications. © 2020 The Wildlife Society.     

Habitat Selection by Female Elk During Minnesota's Agricultural Season

Understanding space-use patterns by elk (Cervus canadensis) is essential to alleviating human-elk conflicts, particularly when crop depredation by elk can make it harder to justify to the public the need to restore elk populations to regions with agricultural landscapes. In 2016–2017, we used global positioning system data from 20 female elk to investigate their selection for agricultural cover during the agricultural season (1 May–31 Oct) in northwestern Minnesota, USA. We estimated resource selection functions with resource availability defined at the home range scale. Elk space use was primarily determined by distance to forest cover in areas proximate to agricultural fields. During diurnal periods, elk selected areas with forest cover near agricultural fields planted with legumes and cereal. During nocturnal periods, elk selected for agricultural fields with little to no canopy and that were planted with legumes. We suggest that management of elk in northwestern Minnesota will require practices that discourage the use of agriculture by elk while improving natural habitats within areas managed for elk restoration. We suggest that forestry practices (i.e., thinning and burning) could improve cover and forage openings for elk in restoration areas. Furthermore, managers could work with agricultural producers where elk occur to plant crops favored by elk (i.e., legumes) outside known home ranges and plant fields within home ranges with crops that elk avoided (i.e., hay). Collectively, these practices may shift the ranges of elk herds into restoration areas and lower conflict between the public and elk restoration efforts. © 2020 The Wildlife Society.     

Fetal Sex Ratios in Southwestern Montana Elk

ABSTRACT The Trivers-Willard (1973) model suggests maternal control of offspring sex, in utero or by the end of parental investment, may be an adaptive advantage in some species. We tested for differential sex allocation using 11,408 known-sex fetal elk (Cervus elaphus) from biological collections and hunter harvest returns from 2 southwestern Montana, USA, elk populations (1961–2007). We included maternal and environmental condition covariates measured pre- and postconception and throughout pregnancy. Results suggested that adult female elk in southwest Montana did not differentially invest in male offspring when conditions were beneficial. We found evidence that, when the Northern Yellowstone elk herd was at low density, beneficial spring (May-Jun) growing conditions, as indexed by a local precipitation measure and a regional drought indicator, correlated with production of more female fetuses (1 SD increase in precipitation and 1 SD decrease in drought resulted in 6% and 5% more F fetuses, respectively). In the same herd, we found evidence that improved maternal condition, as indexed by kidney fat mass and heart fat mass, also correlated with production of more female fetuses (1 SD increase in kidney fat mass and heart fat mass resulted in 8% more F fetuses). When the same elk herd reached higher densities under different ecological conditions, no covariate was associated with a deviation in the 50:50 female-to-male sex ratio. Similarly, there was no association between covariates and fetal sex ratios in a nearby elk herd at high population density. In modeling, wildlife managers should consider factors that could alter sex ratios at birth, and also how biased sex ratios postpartum could affect population models.     

Characterization of 11 polymorphic tetranucleotide microsatellites for forensic applications in California elk (Cervus elaphus canadensis)

Eleven polymorphic tetranucleotide microsatellite loci have been developed for forensic use in the protection of California elk. Based on a reference sample of elk taken from three races throughout California, the loci consist of 4–9 alleles (average 6.125). Probabilities of identity ( Paetkau et al. 1995 ) range from 0.079 to 0.288, with an overall probability of identity of 1.3 × 10^?9 (one in 7.8 × 10⁸).     

Impact of Spatial and Temporal Variation in Calf Survival on the Growth of Elk Populations

Abstract: The realized impact of a vital rate on population growth (λ) is determined by both the relative influence of the vital rate on λ (elasticity) and its magnitude of variability. We estimated mean survival and reproductive rates in elk (Cervus elaphus) and spatial and temporal variation in these rates from 37 sources located primarily across the Rocky Mountain region and northwestern United States. We removed sampling variance from estimates of process variance both within and across vital-rate data sets using the variance discounting method developed by White (2000). Deterministic elasticities calculated from a population matrix model parameterized with these mean vital rates ranked adult female survival (e_Scow = 0.869) much higher than calf survival (e_Scalf = 0.131). However, process variance in calf survival was >11 times greater than process variance in female survival across data sets and 10 times greater on average within studies. We conducted Life-Stage Simulation Analysis to incorporate both vital-rate elasticity patterns and empirical estimates of variability to identify those vital rates most influential in elk population dynamics. The overwhelming magnitude of variation in calf survival explained 75% of the variation in the population growth rates generated from 1,000 matrix replicates, compared to just 16% of the variation in λ explained by variation in female survival. Variation in calf survival greatly impacts elk population growth and calls into question the utility of classical elasticity analysis alone for guiding elk management. These results also suggest that the majority of interannual variability that wildlife managers document in late-winter and spring elk surveys is attributable to variation in calf survival over the previous year and less influenced by variation in the harvest of females during the preceding autumn. To meet elk population size objectives, managers should consider the inherent variation in calf survival, and its apparent sensitivity to management, in addition to female harvest.     

Changes in Elk Resource Selection and Distributions Associated With a Late-Season Elk Hunt

ABSTRACT Changes in resource selection associated with human predation risk may alter elk distributions and availability for harvest. We used Global Positioning System data collected from telemetered female elk (Cervus elaphus) to evaluate effects of refuges (areas where hunting was prohibited), spatial variation in hunting risk, and landscape attributes on resource selection within an established Greater Yellowstone Area, USA, winter range. We also evaluated elk distributions during and outside of a late-season hunting period. Refuge areas and landscape attributes such as habitat type and snow water equivalents (SWE) affected resource selection. Elk selection for flat grasslands increased as SWE increased, likely because these areas were windswept, leaving grasses exposed for foraging. Elk distributions differed during hunting and no-hunting periods. During the hunting period, elk shifted to privately owned refuge areas and the estimated odds of elk occupying refuge areas more than doubled. Risk-driven changes in resource selection resulted in reduced availability of elk for harvest. Elk selection for areas where hunting is prohibited presents a challenge for resource managers that use hunting as a tool for managing populations and influences grazing patterns on private ranchlands.     

Behavioral Responses of North American Elk to Recreational Activity

ABSTRACT Off-road recreation on public lands in North America has increased dramatically in recent years. Wild ungulates are sensitive to human activities, but the effect of off-road recreation, both motorized and nonmotorized, is poorly understood. We measured responses of elk (Cervus elaphus) to recreational disturbance in northeast Oregon, USA, from April to October, 2003 and 2004. We subjected elk to 4 types of recreational disturbance: all-terrain vehicle (ATV) riding, mountain biking, hiking, and horseback riding. Motion sensors inside radiocollars worn by 13 female elk recorded resting, feeding, and travel activities at 5-minute intervals throughout disturbance and control periods. Elk fed and rested during control periods, with little time spent traveling. Travel time increased in response to all 4 disturbances and was highest in mornings. Elk travel time was highest during ATV exposure, followed by exposure to mountain biking, hiking, and horseback riding. Feeding time decreased during ATV exposure and resting decreased when we subjected elk to mountain biking and hiking disturbance in 2003. Our results demonstrated that activities of elk can be substantially affected by off-road recreation. Mitigating these effects may be appropriate where elk are a management priority. Balancing management of species like elk with off-road recreation will become increasingly important as off-road recreational uses continue to increase on public lands in North America.     

A Review of Environmental Factors Affecting Elk Winter Diets

Abstract: Decades of research have produced substantial data on elk (Cervus elaphus) diets in winter, when foraging conditions are most likely to affect population dynamics. Using data from 72 studies conducted in western North America between 1938 and 2002, we collated data on elk diets and environmental variables. We used these data to quantify diet selection by elk and to test whether variation in elk diets is associated with habitat type, winter severity, period of winter, human hunting, and study method. Graminoids (grasses and grass-like plants such as sedges) dominated elk diets and consistently occurred at a higher proportion in the diet than in elk foraging habitats, indicating preference. Forbs commonly made up ≤5% of the diet, with no evidence for preference; we conclude that forb use is largely incidental to grazing for graminoids. Browse was consumed in proportion to its availability, implying that the amount of browse in the diet was primarily determined by habitat use rather than selection. Comparing the diets of elk and sympatric ruminants, elk consistently selected graminoids more strongly than sympatric ruminants with the exception of bison (Bison bison), suggesting that elk are not environmentally forced to adopt the graminoid-biased diet that they normally select. The proportion of open meadows and grasslands on winter ranges was strongly and positively associated with graminoid consumption by elk. The proportion of graminoids in the diet was significantly lower in elk experiencing severe winter conditions or predation risk from human hunting. The period of winter (early, middle, and late) had only small effects on elk diets, as did the method by which the diet was determined. Overall, variation in elk diets is well-explained by a consistent tendency to select graminoids if available, modified by winter habitat type, predation risk, and winter severity, which can constrain habitat selection and access to grazing opportunities. To fully understand variation in foraging behavior, biologists should recognize these broad patterns when interpreting resource selection data. Managers should recognize that inconspicuous behavioral responses to environmental stimuli can alter the diet in ways that probably carry nutritional consequences.     

Association of antler asymmetry with hoof disease in elk

Treponeme-associated hoof disease (TAHD) is an emergent disease of elk (Cervus canadensis) in the Pacific West of the United States. Although lesions are usually restricted to the feet, anecdotal reports suggested increased prevalence of abnormal antlers in affected elk. We used hunter harvest reports for 1,688 adult male elk harvested in southwestern Washington, USA, during 2016-2018, to evaluate anecdotal reports. We used Akaike's Information Criterion to compare 18 logistic regression models describing the prevalence of asymmetrical antlers, indicated by unequal antler point counts. Our leading model (84% of model weight) described additive effects of TAHD (odds ratio = 1.91; 95% CI = [1.49, 2.44]) and maximum number of antler points. Confidence intervals overlapped zero for all other parameters, which described ecotypic, geographic, and age-related effects. Effects of physical injury on antler development have been described elsewhere; however, injuries leading to instances of antler deformity do not have population-level management implications. In contrast, we describe effects of a transmissible disease that was reported by hunters in >35% of adult male elk and was associated with an increase of ≥16 percentage points in the prevalence of gross asymmetry. Unequal point counts are quite common in elk with otherwise typical antlers and seem unlikely to attract public notice or be attributed to hoof lesions; thus, we suspect our results and anecdotal reports reflect more prominent deformities that are important to stakeholders who enjoy hunting and wildlife viewing.     

Elk survival and mortality causes in the Blue Mountains of Washington

We studied survival of elk (Cervus elaphus) ≥1 yr old and quantified mortality sources in the Blue Mountains of Washington, 2003–2006, following a period of extensive poaching. The population was managed under a spike-only general hunting season, with limited permits for larger males and for females. We radiomarked 190 elk (82 males and 39 females >1 yr old and 65 males 11 months old), most with rumen transmitters and neck radiocollars; 60 elk only received rumen transmitters. We estimated annual survival using known fate models and explored survival differences among sex and age classes and in 2 potentially different vulnerability zones for males. We found little support for differences in survival between younger (2–3-yr old) and older (≥4-yr old) branch-antlered males or zone differences for yearling males. A model with zone differences for branch-antlered males was the second ranked model and accounted for 14% of the available model weight. From the best-supported models, we estimated annual survival for yearling males at 0.41 (95% CI: 0.29–0.53). We estimated pooled adult female survival at 0.80 (95% CI: 0.64–0.93); when an age-class effect was included, point estimates were higher for prime-aged females (2–11 yr: S = 0.81 [0.70–0.88]) than for older females (≥12 yr: S = 0.72 [0.56–0.83]), but confidence intervals broadly overlapped. Only 1 of 7 models with a female age effect on survival was among the competitive models. For branch-antlered males, survival ranged 0.80–0.85, depending on whether zone variation was modeled. We recorded 78 deaths of radiomarked elk. Human-caused deaths (n = 55) predominated among causes and most were of yearling males killed during state-sanctioned hunts (n = 28). Most subadult male deaths were from tribal hunting (n = 5), and most mature males died from natural causes (n = 6) and tribal hunting (n = 5). We detected few illegal kills (n = 4). Our results suggest that increased enforcement effectively reduced poaching, that unreported tribal harvest was not a trivial source of mortality, and that spike-only general seasons were effective in recruiting branch-antlered males. © 2011 The Wildlife Society.