Elk Population Research Articles

Large herbivores in a partially migratory population search for the ideal free home.

Migration is a tactic used across taxa to access resources in temporally heterogenous landscapes. Populations that migrate can attain higher abundances because such movements allow access to higher quality resources, or reduction in predation risk resulting in increased fitness. However, most migratory species occur in partially migratory populations, a mix of migratory and non-migratory individuals. It is thought that the portion of migrants in a partial migration population is maintained either through (1) a population-level evolutionary stable state where counteracting density-dependent vital rates act on migrants and residents to balance fitness or (2) conditional migration, where the propensity to migrate is influenced by the individual's state. However, in many respects, migration is also a form of habitat selection and the proportion of migrants and residents may be the result of density-dependent habitat selection. Here, we test whether the theory of Ideal Free Distribution (IFD) can explain the coexistence of different migratory tactics in a partially migratory population. IFD predicts individuals exhibit density-dependent vital rates and select different migratory tactics to maximize individual fitness resulting in equal fitness (λ) between tactics. We tested the predictions of IFD in a partially migratory elk population that declined by 70% with 19 years of demographic data and migratory tactic switching rates from >300 individuals. We found evidence of density dependence for resident pregnancy and adult female survival providing a fitness incentive to switch tactics. Despite differences in vital rates between migratory tactics, mean λ (fitness) was equal. However, as predicted by the IFD, individuals switched tactics toward those of higher fitness. Our analysis reveals that partial migration may be driven by tactic selection that follows the ideal free distribution. These findings reinforce that migration across taxa may be a polymorphic behavior in large herbivores where migratory tactic selection is determined by differential costs and benefits, mediated by density dependence.

Influences on food supply from elk abundance and precipitation early in the growing season.

Large grazing mammals should negatively affect forage biomass of their food supply, but documentation is lacking in free ranging populations. Furthermore, complications from factors such as weather patterns and spatial heterogeneity might obscure grazing effects on the food supply. We examined influences of Roosevelt elk (Cervus canadensis roosevelti (Merriam, 1897)) abundance and precipitation on forage biomass at two spatial scales; meadows that contained most of the food supply, and sectors nested in meadows. Spatial heterogeneity in forage biomass might also decline with increasing elk abundance. Elk abundance was estimated from population counts and varied 3.9-fold across the 15 years of study in northwestern California, USA. Each January, early in the growing season, we estimated forage biomass in the 50-ha meadow complex used by the elk population. Measures of palatable forage cover and height were taken in 270 ¼ m2 plots dispersed throughout sectors. These measurements were then related to dried forage biomass. At both spatial scales, elk abundance was inversely, and precipitation was positively related to forage biomass. At the sector scale, analysis of a linear mixed effect model indicated heterogeneity. In some sectors both predictors were related to forage biomass and in other sectors they were not. Heterogeneity was not from uneven elk grazing as elk grazed sectors in proportion to forage biomass. The varied elk abundance–forage biomass relationships across sectors indicated that spatial heterogeneity declined with increasing elk abundance. Detecting relationships between free ranging ungulate populations and biomass of their food supply is not straightforward.

A multi‐metric movement model for identifying elk parturition events

AbstractFor wildlife managers, identifying the time and location of ungulate parturition events is necessary to protect parturition habitat and inform population models. Current methods for identifying parturition events include neonatal capture and monitoring and visual analysis of location data, which are resource intensive and subject to biases. Recently, movement‐based analyses using the spatial and temporal patterns contained in location data have shown promise for identifying parturition behavior; however, questions regarding efficacy and best practice have limited the adoption of such movement‐based parturition models into management programs. We used location data collected between 2017−2018 from a California population of female Roosevelt elk with known parturition status to build a set of movement‐based models. We compared each model's ability to accurately classify individual's parturition status and identify the timing of parturition. The top model showed that within 72 hours of a parturition event, elk made smaller movements, had smaller home ranges, and had longer visits to individual locations. Of the 16 individuals in our study with known parturition status, our approach to classifying an individual's status was 81% accurate in cross‐validation, which increased to 100% accuracy when the complete dataset was used to train the top model. We then used the top, global and single‐metric models to establish probability thresholds and identify parturition events for collared‐elk with unknown parturition status. Our results align with a growing number of studies that have shown movement‐based parturition models are a reliable method that could augment or replace field‐based techniques for identifying parturition events and quantifying parturition rates in ungulate populations.

Estimating Wildlife Density as a Function of Environmental Heterogeneity Using Unmarked Data

Recent developments to spatial-capture recapture models have allowed their use on species whose members are not uniquely identifiable from photographs by including individual identity as a latent, unobserved variable in the model. These ‘unmarked’ spatial capture recapture (uSCR) models have also been extended to presence-absence data and modified to allow categorical environmental covariates on density, but a uSCR model, which allows fitting continuous environmental covariates to density, has yet to be formulated. In this paper, we fill this gap and present an extension to the uSCR modeling framework by modeling animal density on a discrete state space as a function of continuous environmental covariates and investigate a form of Bayesian variable selection to improve inference. We used an elk population in their winter range within Karuk Indigenous Territory in Northern California as a case study and found a positive credible effect of increasing forb/grass cover on elk density and a negative credible effect of increasing tree cover on elk density. We posit that our extensions to uSCR modeling increase its utility in a wide range of ecological and management applications in which spatial counts of wildlife can be derived and environmental heterogeneity acts as a control on animal density.

Non-invasive monitoring of multiple wildlife health factors by fecal microbiome analysis.

Fecal microbial biomarkers represent a less invasive alternative for acquiring information on wildlife populations than many traditional sampling methodologies. Our goal was to evaluate linkages between fecal microbiome communities in Rocky Mountain elk (Cervus canadensis) and four host factors including sex, age, population, and physical condition (body‐fat). We paired a feature‐selection algorithm with an LDA‐classifier trained on elk differential bacterial abundance (16S‐rRNA amplicon survey) to predict host health factors from 104 elk microbiomes across four elk populations. We validated the accuracy of the various classifier predictions with leave‐one‐out cross‐validation using known measurements. We demonstrate that the elk fecal microbiome can predict the four host factors tested. Our results show that elk microbiomes respond to both the strong extrinsic factor of biogeography and simultaneously occurring, but more subtle, intrinsic forces of individual body‐fat, sex, and age‐class. Thus, we have developed and described herein a generalizable approach to disentangle microbiome responses attributed to multiple host factors of varying strength from the same bacterial sequence data set. Wildlife conservation and management presents many challenges, but we demonstrate that non‐invasive microbiome surveys from scat samples can provide alternative options for wildlife population monitoring. We believe that, with further validation, this method could be broadly applicable in other species and potentially predict other measurements. Our study can help guide the future development of microbiome‐based monitoring of wildlife populations and supports hypothetical expectations found in host‐microbiome theory.

Examination of the interaction between age-specific predation and chronic disease in the Greater Yellowstone Ecosystem.

Predators may create healthier prey populations by selectively removing diseased individuals. Predators typically prefer some ages of prey over others, which may, or may not, align with those prey ages that are most likely to be diseased. The interaction of age-specific infection and predation has not been previously explored and likely has sizable effects on disease dynamics. We hypothesize that predator cleansing effects will be greater when the disease and predation occur in the same prey age groups. We examine the predator cleansing effect using a model where both vulnerability to predators and pathogen prevalence vary with age. We tailor this model to chronic wasting disease (CWD) in mule deer and elk populations in the Greater Yellowstone Ecosystem, with empirical data from Yellowstone grey wolves and cougars. Model results suggest that under moderate, yet realistic, predation pressure from cougars and wolves independently, predators may decrease CWD outbreak size substantially and delay the accumulation of symptomatic deer and elk. The magnitude of this effect is driven by the ability of predators to selectively remove late-stage CWD infections that are likely the most responsible for transmission, but this may not be the age class they typically select. Thus, predators that select for infected young adults over uninfected juveniles have a stronger cleansing effect, and these effects are strengthened when transmission rates increase with increasing prey morbidity. There are also trade-offs from a management perspective-that is, increasing predator kill rates can result in opposing forces on prey abundance and CWD prevalence. Our modelling exploration shows that predators have the potential to reduce prevalence in prey populations when prey age and disease severity are considered, yet the strength of this effect is influenced by predators' selection for demography or body condition. Current CWD management focuses on increasing cervid hunting as the primary management tool, and our results suggest predators may also be a useful tool under certain conditions, but not necessarily without additional impacts on host abundance and demography. Protected areas with predator populations will play a large role in informing the debate over predator impacts on disease.

Incorporating vital rates and harvest into stochastic population models to forecast elk population dynamics

AbstractThe dynamics of ungulate populations across variable ecosystems and management strategies demonstrate disparate trajectories such that some populations are overabundant, while other populations are subject to recovery efforts. Understanding how variation in vital rates such as pregnancy and survival integrate to shape the trajectories of populations is, therefore, helpful for informed management, particularly given that our understanding of the dynamics of harvested ungulate populations is often limited. Age‐related variation in vital rates among elk (Cervus canadensis) suggest that suitable population matrix models require age‐specific vital rates that can be logistically and analytically challenging to obtain. Our goals were to use a large, long‐term data set on elk and hierarchical Bayesian models to estimate age‐specific pregnancy and annual survival rates and their process variances, use stochastic population projection matrices to understand the effects of additional mortality from harvest on population dynamics, and identify the influence of different combinations of vital rates on population trajectories. We found that median age‐specific pregnancy rates increased with age from yearlings (0.52, 90% credible interval [CrI] = 0.37, 0.65) to a plateau among prime ages (e.g., 9‐year‐old: 0.91, 90% CrI = 0.87, 0.94), followed by a decline for the oldest ages (e.g., 19‐year‐old: 0.10, 90% CrI = 0.03, 0.28). Annual survival rates plateaued among prime‐aged animals (e.g., 9‐year‐old: 0.94, 90% CrI = 0.92, 0.96), and declined for the oldest‐ages (e.g., 19‐year‐old: 0.21, 90% CrI = 0.04, 0.56). We found higher process variation in pregnancy rates than survival rates; annual pregnancy rates for a 7‐year‐old varied from 0.82 (90% CrI = 0.67, 0.92) to 0.98 (90% CrI = 0.95, 0.99), and annual survival rates varied from 0.94 (90% CrI = 0.85, 0.96) to 0.96 (90% CrI = 0.93, 0.99). Simulated population trajectories indicated that additional mortality due to harvest resulted in a shift in the age structure towards younger animals with lower probabilities of pregnancy. When we held calf survival between 0.48 and 0.50 and specified constant pregnancy rates, changes in age structure alone resulted in variation of the recruitment of female calves from 0.20 to 0.16. We found that populations with a low mean value of calf survival (0.25) and no additional mortality due to harvest had marginal demographic performance ( = 1.02) and could sustain no additional mortality from harvest and still increase. In contrast, productive populations with a high mean value of calf survival (0.75) required high harvests to abate population growth (e.g., harvest rate = 0.20, = 0.94). Finally, we found a temporally lagged effect of harvest on age structure such that a shift towards younger animals could persist for multiple years following a reduction in harvest, suggesting that harvest may have multi‐year lagged depressive effects on population growth rates above and beyond the direct effects on survival rates. Our work highlights the importance of considering the effect of varying age‐structure on population dynamics, suggests minimum combinations of vital rates required for increasing or decreasing elk population growth rates to general management objectives, and provides the framework required for future management‐specific recommendations using stochastic population projection matrices.

Association Study of the M132L Single Nucleotide Polymorphism With Susceptibility to Chronic Wasting Disease in Korean Elk: A Meta-Analysis.

Chronic wasting disease (CWD) is a deleterious brain proteinopathy caused by a pathogenic form of prion protein (PrPSc), which is converted from a benign form of prion protein (PrPC) encoded by the prion protein gene (PRNP). In elk, the M132L single nucleotide polymorphism (SNP) of the PRNP gene likely plays a pivotal role in susceptibility to CWD. However, the association of the M132L SNP with susceptibility to CWD has not been evaluated in Korean elk to date. To estimate the association of the M132L SNP with susceptibility to CWD in Korean elk, we investigated the genotype and allele frequencies of the M132L SNP by amplicon sequencing and performed association analysis between CWD-positive and CWD-negative elk. In addition, we performed a meta-analysis to evaluate the association between the M132L SNP and susceptibility to CWD in quantitatively synthesized elk populations. Furthermore, we estimated the effect of the M132L SNP on elk PrP using in silico programs, including PolyPhen-2, PROVEAN, AMYCO and Swiss-PdbViewer. We did not identify a significant association between the M132L SNP of PRNP and susceptibility to CWD in Korean elk. The meta-analysis also did not identify a strong association between the M132L SNP of PRNP and susceptibility to CWD in quantitatively synthesized elk populations. Furthermore, we did not observe significant changes in structure, amyloid propensity or electrostatic potential based on the M132L SNP in elk PrP. To the best of our knowledge, this was the first report of an association analysis and meta-analysis in Korean elk and quantitatively synthesized elk populations, respectively.

A comparative analysis of genetic diversity of natural elk (Alces alces L.) populations from European Russia and Sumarokov elk farm population

AIM: The aim of the study is to compare the genetic diversity of two natural elk populations from the hunting farms in adjacent regions (Kostromskaya and Yaroslavskaya oblasts) with that of the man-made population of an elk farm.
 MATERIALS AND METHODS: The genetic diversity analysis was carried out using DNA-markers represented by nine microsatellite loci (169 samples).
 RESULTS: The genetic diversity level in the wild populations is reliably higher than in the elk farm population: the average allele-per-locus numbers (NA) for the natural populations are 9.0 and 8.6 respectively, for the elk farm population 5.9. All the populations studied do not differ in average heterozygosity level. The allele frequency heterogeneity test shows that all the populations differ in 6 loci and a sum of 9 loci, the natural populations differ in 5 loci, and the elk farm population differs from both the natural ones in the same 3 loci. The inbreeding coefficient for the Yaroslavskaya population (0.167) is way higher than for the Kostromskaya population (0.053), it is 0.165 for the elk farm population. With the identified gene flow (Nm = 16.7), the genetic divergence of the wild populations persists, so they do not stem from a single population.
 CONCLUSIONS: The slump found in the genetic diversity of natural elk population points to the necessity of gene pool enrichment, and the high inbreeding in wild populations implies that control over gene pool is needed.

Spatial network clustering reveals elk population structure and local variation in prevalence of chronic wasting disease

AbstractSpatial organization plays prominent roles in disease transmission, genetics, and demography of wildlife populations and is therefore an important consideration not only for wildlife management, but also for inference about populations and processes. We used hierarchical agglomerative clustering of a spatial graph network to partition Wind Cave National Park (WICA) into five regions used by 163 female elk (Cervus elaphus) marked with global positioning system collars during 2005–08 and 2011–13. We grouped elk based on differential use of the five regions, developed a priori models for inter‐group variation in the occurrence of chronic wasting disease (CWD), and used Akaike's information criterion to compare models and stratify regions. Previous descriptions of elk population structure, which have been based on social contact or overlap of individual ranges, have distinguished spatially disjunct population subsets. Constructing hierarchical partitions of the landscape enabled us to also discern and describe overlapping and nested subsets. During 2016–18, apparent park‐wide prevalence of CWD was 0.18 (90% CI = [0.146, 0.182]); however, prevalence within three spatial strata used primarily by different elk ranged from 0.03 ([0.008, 0.074]) to 0.29 ([0.211, 0.375]). In context with published estimates of recruitment, predation, and anthropogenic mortality, such differences in prevalence equate to increasing local abundance of elk in southwestern WICA, stable to declining abundance in the west/northwest, and rapidly declining abundance in the east. Despite the modest size of WICA (11,357 ha), park‐wide averages conflate effects of elk distribution and disease, obscuring spatial patterns with profound implications for study and management of elk and CWD. Graph networks have been used widely in ecology to describe such phenomena as social relationships, connectivity of habitat patches, animal movements, and the spread of disease. Extension to partitioning of geographic range is straightforward but entails different considerations. We discuss allocation of sampling effort, construction of an initial partition, specification of a model for graph cohesion, selection of a clustering algorithm, and identification of useful partitions.

Оценка кормовой базы лося европейского в лесном фонде охотхозяйства «Вологодское»

Using the example of the hunting farm «Vologodskoye», an assessment of the stocks of the fodder base of the European elk population was carried out and the optimal number of individuals from the point of view of damage and restoration of feed stocks was determined. At winter stations, it was found that the most visited areas by elk are plantations with the presence of young trees and shrubs, mainly deciduous — aspen (up to 25 years old), willow (up to 10 years old), birch (up to 20 years old), gray alder (up to 12 years old). The potential supply of branch fodder at winter stations reaches 1,62 tons, the winter consumption period is 220–230 days. The daily requirement for twig feed for one elk is 7–20 kg (depending on the age of the individuals), the annual consumption of winter wood-twig feed by one moose is about 3 tons. It has been established that, taking into account the potential stock of used feed and the volume of annual feed consumption, it is possible to feed 0,5 elk in the surveyed area of winter habitats, and 418 individuals, calculated for the entire area of the farm suitable for the habitat of the species.

Supporting adaptive management with ecological forecasting: chronic wasting disease in the Jackson Elk Herd

AbstractAdaptive management has emerged as the prevailing approach for combining environmental research and management to advance science and policy. Adaptive management, as originally formulated by Carl Walters in 1986, depends on the use of Bayesian models to provide a framework to accumulate knowledge. The emergence of ecological forecasting using the Bayesian framework has provided robust tools and supports a new approach to informing adaptive management, which can be particularly useful in developing policy for managing infectious disease in wildlife. We used the potential infection of elk populations with chronic wasting disease in the Jackson Valley of Wyoming and the National Elk Refuge as a model system to show how Bayesian forecasting can support adaptive management in anticipation of management challenges. The core of our approach resembles the sex‐ and age‐structured, discrete time models used to support management decisions on elk harvest throughout western North America. Our model differs by including stages for CWD‐infected and unaffected animals. We used data on population counts, sex and age classification, and CWD testing, as well as results from prior research, in a Bayesian statistical framework to predict model parameters and the number of animals in each age, sex, and disease stage over time. Initial forecasts suggested CWD may reach a mean prevalence in the population of 12%, but uncertainty in this forecast is large and we cannot rule out a mean forecasted prevalence as high as 20%. Using recruitment rates observed during the last two decades, the model predicted that a CWD prevalence of 7% in females would cause the population growth rate () to drop below 1, resulting in population declines even when female harvest was zero. The primary value of this ecological forecasting approach is to provide a framework to assimilate data with understanding of disease processes to enable continuous improvement in understanding the ecology of CWD and its management.

Integrating socioecological suitability with human–wildlife conflict risk: Case study for translocation of a large ungulate

AbstractTranslocations are essential for re‐establishing wildlife populations. As they sometimes fail, it is critical to assess factors that influence their success pre‐translocation.Socioecological suitability models (SESMs) integrate social acceptance and ecological suitability to enable identification of areas where wildlife populations will expand, which makes it likely that SESMs will also be useful for predicting translocation success.To inform site selection for potential elkCervus canadensisreintroduction to north‐eastern Minnesota, United States, we developed broadscale maps of social acceptance from surveys of local residents and landowners, animal use equivalence (AUE) from forage measured in the field and empirical conflict risk from geospatial data. Resulting SESMs integrated social acceptance favourability scores, AUE and conflict risk, and weighted SESMs showed the relative influences of acceptance and conflict.Social acceptance was positive for local residents and landowners (mean ≥ 5.4; scale of 1–7). AUE (scaled to an elk home range) ranged between 1 and 9 elk/16 km2during winter, and from 14 to 83 elk/16 km2during summer. Human–elk conflict risk was low (mean ≤ 0.10; scaled 0–1), increasing from north to south. Geographical distributions differed for social acceptance, AUE and conflict risk, and weighted SESMs revealed unsuitable areas that were otherwise obscured.Synthesis and applications. Integrating human–wildlife conflict risk into SESMs shows where social acceptance of translocated species is likely to erode, even where viewed favourably pre‐translocation, to inform translocation planning by highlighting interactions between key factors. Such integrated models supplement existing reintroduction biology frameworks by supporting decision‐making and knowledge development. In north‐eastern Minnesota, natural resource managers who are considering elk reintroductions are using SESMs reported here to identify where human–elk conflict is unlikely to result in an isolated elk population and where addressing concerns for area residents about conflict risk is essential.

Elk Responses to Management Hunting and Hazing

ABSTRACTHuman‐wildlife conflicts are widespread around the world and result in property damage, disease spillover, financial loss, and decreased tolerance of wildlife. Increasing elk (Cervus canadensis) populations and land‐use changes in the western United States are challenging resource managers tasked with managing conflict. Lethal and non‐lethal management actions are commonly used to remove elk from conflict zones where they are not desired. We used radio‐collar location data collected from female elk in 2 study areas in Montana, USA, from 2017–2020 to evaluate population‐ and individual‐level responses to management actions (i.e., hunting, hazing) and environmental factors (i.e., weather, season, time of day). First, we used a generalized linear model with a logit link to evaluate the effects of hunting, hazing, time period, seasonality, and weather on the proportion of collared elk that used a conflict zone. Second, we used an ordinary linear model to assess the influence of hunting, hazing, seasonality, and weather on the duration of time that individual elk remained away from conflict zones. The proportion of elk using conflict zones was reduced by hunting, modestly reduced by hazing and increasing snowpack for 1 study area, increased at night, and decreased by a seasonal trend across months. The time individual elk remained away from conflict zones increased with the number of hazing events that occurred during an event and showed a modest seasonal trend increasing across months. For 1 study area, time away increased with the number of hunting days during an event and increasing snowpack, but the increase was biologically trivial. Our results indicate mixed responses of elk to hunting and hazing actions and provide evidence that management actions can influence elk use of conflict areas. Agencies trying to reduce conflicts may want to consider a combination of hunting and hazing, while accounting for site‐specific characteristics to keep elk away from conflict zones. © 2021 The Wildlife Society.

Mothers' Movements: Shifts in Calving Area Selection by Partially Migratory Elk

ABSTRACTLoss of migratory behavior or shifts in migratory ranges are growing concerns to wildlife managers. How ungulates prioritize safety from predators at the expense of high‐quality foraging opportunities during calving may be key to understanding these shifts and long‐term reproductive success. We compared trade‐offs in selection for forage and predation risk by elk (Cervus canadensis) following 3 migratory tactics (western and eastern migration and resident) during 2 time periods in a declining (by almost 70% from 2002–2016), partially migratory elk population adjacent to Banff National Park in Alberta, Canada. We hypothesized that regardless of migratory tactic, maternal elk would show stronger trade‐offs between high‐quality foraging associated with higher predation risk and forage resources of lower‐quality yet lower risk on calving ranges than on ranges used during summer because of vulnerability of their offspring. Additionally, we hypothesized these trade‐offs would occur at high (2002–2006) and low (2013–2016) elk population sizes. We used a machine‐learning algorithm to predict dates of parturition based on global positioning system (GPS) movements of elk equipped with vaginal implants (n = 60) and predictions were within 1.43 ± 0.85 (SE) days of the known date. We applied the model to an additional 58 GPS‐collared elk without vaginal implants. Based on changes in localized movements, we defined calving areas as the 26 days post‐parturition and compared habitat characteristics of calving areas to 10 similar‐sized areas centered on random locations during summer for the same individual in a latent selection framework. Across the 2 time periods, parturition occurred from 8 May–11 July with median parturition dates differing among migratory tactics and residents shifting towards an earlier parturition date in the later period. All elk, regardless of migratory tactic and time period, selected calving areas with greater forage resources than were available on areas used during summer, with no evidence for greater selection of areas that reduced predation risk at the expense of higher‐quality foraging. Calving season selection for areas with abundant forage exposed western migrants to high risk of bear (Ursusspp.) predation, residents to high risk of wolf (Canis lupus) predation, and eastern migrants to low risk of bear and wolf predation. Patterns in exposure to predation risk during calving between migratory tactics were consistent with the recent decline in western migrants and increase in eastern migrants, implying that conditions on calving areas contributed to observed changes in the number of elk following these tactics. © 2021 The Wildlife Society.

Prescribed fire has slight influence on Roosevelt elk population dynamics

Prescribed fires often stimulate short-term productivity of grasslands that influences use by large, grazing herbivores. But studies examining burning effects on large herbivore population dynamics while simultaneously considering other environmental factors that might also influence population dynamics are lacking. We examined the influences of burned area, precipitation during the growing season, and possible distributional shifts from a nearby public hunt on maximum intrinsic rate of population growth (rmax) and environmental carrying capacity (K). We examined the influences of these predictors in a Roosevelt elk (Cervus elaphus roosevelti) population studied across 43 years where abundances ranged from 4 to 322 animals and prescribed fires ranged from 14 to 891 ha of burned area in Redwood National and State Parks, California, USA. The highest count across surveys conducted in a year was our index of elk (females, juveniles, subadult males) abundance. We estimated Ricker type models in a hierarchical, state-space formulation that separated observer error from process variation. We found a slight influence from burned area on both rmax and K but a stronger influence from precipitation during the growing season. The lack of a substantial effect from burned area on elk population parameters might be from a variety of factors such as spatial and temporal variation in intensity of prescribed fires and weak density dependence. Nonetheless, one positive benefit to elk population processes was that the patchwork of burning retarded encroachment of woody plants into forage habitat and, thus, maintained a constant area of forage habitat across 43 years.

Assessing genetic diversity and connectivity in a tule elk (Cervus canadensis nannodes) metapopulation in Northern California

The tule elk (Cervus canadensis nannodes) is a California endemic subspecies that experienced an extreme bottleneck (potentially two individuals) in the mid-1800s. Through active management, including reintroductions, the subspecies has grown to approximately 6000 individuals spread across 22 recognized populations. The populations tend to be localized and separated by unoccupied intervening habitat, prompting targeted translocations to ensure gene flow. However, little is known about the genetic status or connectivity among adjacent populations in the absence of active translocations. We used 19 microsatellites and a sex marker to obtain baseline data on the genetic effective population sizes and functional genetic connectivity of four of these populations, three of which were established since the 1980s and one of which was established ~ 100 years ago. A Bayesian assignment approach suggested the presence of 5 discrete genetic clusters, which corresponded to the four primary populations and two subpopulations within the oldest of them. Effective population sizes ranged from 15 (95% CI 10–22) to 51 (95% CI 32–88). We detected little or no evidence of gene flow among most populations. Exceptions were a signature of unidirectional gene flow to one population founded by emigrants of the other 30 years earlier, and bidirectional gene flow between subpopulations within the oldest population. We propose that social cohesion more than landscape characteristics explained population structure, which developed over many generations corresponding to population expansion. Whether or which populations can grow and reach sufficient effective population sizes on their own or require translocations to maintain genetic diversity and population growth is unclear. In the future, we recommend pairing genetic with demographic monitoring of these and other reintroduced elk populations, including targeted monitoring following translocations to evaluate their effects and necessity.

A pseudomolecule assembly of the Rocky Mountain elk genome.

Rocky Mountain elk (Cervus canadensis) populations have significant economic implications to the cattle industry, as they are a major reservoir for Brucella abortus in the Greater Yellowstone area. Vaccination attempts against intracellular bacterial diseases in elk populations have not been successful due to a negligible adaptive cellular immune response. A lack of genomic resources has impeded attempts to better understand why vaccination does not induce protective immunity. To overcome this limitation, PacBio, Illumina, and Hi-C sequencing with a total of 686-fold coverage was used to assemble the elk genome into 35 pseudomolecules. A robust gene annotation was generated resulting in 18,013 gene models and 33,422 mRNAs. The accuracy of the assembly was assessed using synteny to the red deer and cattle genomes identifying several chromosomal rearrangements, fusions and fissions. Because this genome assembly and annotation provide a foundation for genome-enabled exploration of Cervus species, we demonstrate its utility by exploring the conservation of immune system-related genes. We conclude by comparing cattle immune system-related genes to the elk genome, revealing eight putative gene losses in elk.

ROAD AND RAIL FATALITIES OF ELK, BIGHORN SHEEP, AND GRAY WOLVES IN JASPER NATIONAL PARK, ALBERTA, 1980–2018

Established in 1907, Jasper National Park (JNP) comprises 10,880 km2 of mountainous terrain in western Alberta, Canada. Its large mammals have been protected from hunting and trapping, but are subject to accidental collisions with vehicles and trains on the Yellowhead Highway and the Canadian National Railway (CNR) that transect JNP. This paper reviews the park's historical inventory of Elk (Cervus elaphus), Bighorn Sheep (Ovis Canadensis), and Gray Wolves (Canis lupus), and reports on their number killed by vehicles and trains from 1980 to 2018. Elk population estimates declined from 1000 in 1975 to 318 in 2018. An aerial survey of Bighorn Sheep flown in 2018 over all of JNPs sheep range recorded a decline of 58–62% compared to 1987. In the lower main valley, discrete bands of rams and ewes declined on 2 traditional winter ranges. The road and rail fatalities of Elk and sheep were superimposed on predation. In the late 1970s, wolves were estimated at 160, but reached an undetermined low in 2018 following year-round trapping on JNPs boundaries and accidental fatalities on the park's roads and railways.

Whole-genome sequencing of Tarim red deer (Cervus elaphus yarkandensis) reveals demographic history and adaptations to an arid-desert environment

BackgroundThe initiation of desert conditions in the Tarim Basin in China since the late Miocene has led to the significant genetic structuring of local organisms. Tarim Red Deer (Cervus elaphus yarkandensis, TRD) have adapted to the harsh environmental conditions in this basin, including high solar radiation and temperature, aridity, and poor nutritional conditions. However, the underlying genetic basis of this adaptation is poorly understood.ResultsWe sequenced the whole genomes of 13 TRD individuals, conducted comparative genomic analyses, and estimated demographic fluctuation. The ∂a∂i model estimated that the TRD and Tule elk (Cervus canadensis nannodes) populations diverged approximately 0.98 Mya. Analyses revealed a substantial influence of the Earth’s climate on the effective population size of TRD, associated with glacial advances and retreat, and human activities likely underlie a recent serious decline in population. A marked bottleneck may have profoundly affected the genetic diversity of TRD populations. We detected a set of candidate genes, pathways, and GO categories related to oxidative stress, water reabsorption, immune regulation, energy metabolism, eye protection, heat stress, respiratory system adaptation, prevention of high blood pressure, and DNA damage and repair that may directly or indirectly be involved in the adaptation of TRD to an arid-desert environment.ConclusionsOur analyses highlight the role of historical global climates in the population dynamics of TRD. In light of ongoing global warming and the increasing incidence of droughts, our study offers insights into the genomic adaptations of animals, especially TRD, to extreme arid-desert environments and provides a valuable resource for future research on conservation design and biological adaptations to environmental change.