Winter Elk Distribution and the Risk Of Brucellosis Transmission from Elk to Livestock in the Northern Greater Yellowstone Ecosystem

Predicting spatio-temporal variations in elk (Cervus elaphus) distributions is necessary to forecast the risk of brucellosis transmission from elk to livestock within the Greater Yellowstone Ecosystem (GYE). Using Global Positioning System (GPS) data collected from 49 telemetry-collared female elk during 2005-2006, we developed predictive resource selection function models for the brucellosis transmission risk period. To determine applicability of predictive models across the larger GYE landscape, we validated predictive models internally, as well as externally at two additional elk ranges within the GYE using 63 telemetry-collared cow elk during 2002-2009. Finally, we integrated extrapolated resource selection function maps and domestic livestock distributions to forecast elk to domestic livestock brucellosis transmission risk. We found elk distributions varied spatially and temporally during the risk period and predictive accuracy was highest in the study area where the model was developed. Predictive accuracy of extrapolated resource selection function maps was lower in other study areas indicating that risk models developed in one portion of the GYE are not as accurate in other portions of the GYE. Relative to the other areas included in this study, the Madison Valley and northern Paradise Valley areas were predicted to have the highest risk of elk to livestock transmission risk. Predictions regarding spatio-temporal variations in transmission risk may be used to prioritize management actions aimed at reducing the potential for brucellosis transmission risk, for example hazing to reduce elk-livestock commingling or producer management of livestock distribution

Effects Of A Rest-Rotation Grazing System On Wintering Elk Distributions On The Wall Creek, Montana Winter Range

Understanding livestock grazing effects on wildlife remains an important conservation issue. The purpose of this project was to evaluate the effects of a rest-rotation grazing system on elk resource selection within the Wall Creek winter range in southwest Montana. We collected bi-weekly observations of elk (Cervus elaphus) number and distributions across the winter range from 1988-2007. Using a matched-case control logistic regression model to estimate selection coefficients, we evaluated the effects of annual green-up conditions, winter conditions, landscape features, and grazing treatment on elk resource selection within the grazing system. We found that within the grazing system, elk preferentially selected for rested pastures over pastures that were grazed the previous summer. The strength of selection against the pasture grazed during the growing season was strongest, and pastures grazed during the early and late summer were selected for over the pasture grazed during the growing season. The number of elk utilizing the grazing system increased in the 19 years following implementation of the grazing system; however, total elk herd size also increased during this time. We found no evidence that the proportion of the elk herd utilizing the grazing system changed following implementation of the rest-rotation grazing system. Our results provide support for the principals of rest-rotation grazing systems. Wintering elk preference for rested pastures suggests rested pastures play an important role in rotation grazing systems by conserving forage for wintering elk. We recommend wildlife managers maintain rested pastures within rotation grazing systems existing on ungulate winter range

One-Year Progress Report for the Montana Statewide Bighorn Sheep Research Project

Restoration and conservation of bighorn sheep has been a challenge. Despite strong conservation efforts, bighorn sheep have not recovered to historic range and numbers as most other ungulates have. The Montana Statewide Bighorn Sheep Research Project, a collaborative effort between Montana Department of Fish Wildlife & Parks and Montana State University, began operations in winter 2013/2014 in order to provide information to help guide future management and conservation of bighorn sheep. Seven bighorn sheep populations were scheduled to be sampled in the first year of the study and this presentation will outline the accomplishments, challenges, and findings from the first year of the research effort. Research objectives are to quantify and compare exposure to and prevalence of pneumonia pathogens, body condition, habitat use and demographic rates in multiple bighorn sheep populations with varying histories and characteristics across Montana.  Study plans and initial findings relevant to these objectives will be presented

Mule Deer Research and Management in the Bitterroot Valley, Western Montana

Mule deer in the Sapphire Mountains on the east side of the Bitterroot Valley exist across a variety of habitats, densities, and management strategies, including the most popular trophy buck management area in the state of Montana (Hunting District 270 in the south end of the Sapphires). As in many other western states, mule deer populations have declined over recent decades, despite relatively good fawn recruitment. Beginning in winter 2015-2016, we used ground-based darting to deploy GPS collars on 30 adult female deer in HD270 and HD204 (north end of the Sapphires) to evaluate seasonal movements and causes of mortality. These areas were chosen not only because they represent a spectrum of environmental and management conditions, but because extensive data on habitat and forage quality in this area was collected as part of preceding elk habitat research. To date, we have observed a wide variety of movement strategies, from resident deer maintaining a small home range year-round in areas of high private land ownership to migratory deer moving from summer to winter range. Causes of mortality consisted of coyote predation (n=2), human hunting (n=1), and unknown mortality (n=1) in HD204, and natural mortality (n=1) and mountain lion predation (n=2) in HD270. This is an ongoing study by which we hope to evaluate factors limiting deer populations to help inform future management

Population Monitoring and Modeling to Enable an Adaptive Management Strategy for Mountain Lions in Montana

Historically, managing harvested mountain lion populations was confounded by the lack of a method to affordably, accurately, and repeatedly estimate a population’s size, make rigorous predictions about the effect of future harvest prescriptions, and monitor population trends over time. Managers were unable to fully implement an adaptive mountain lion harvest management program because they lacked the necessary objective monitoring and modeling information. Disagreement about the past, and potential, effects of management decisions led to conflict among stakeholders and with FWP. Montana has now developed a draft mountain lion Management Strategy that will allow FWP to actively monitor statewide mountain lion populations using new genetic spatial capture-recapture field techniques and to routinely extrapolate those local estimates across discrete mountain lion ecoregions using a statistical resource selection function. Managers will then be able to input these population estimates, along with lion demographic parameters (described by regional field research), into a web-based mountain lion integrated population model in order to predict the likely effect of future harvest prescriptions on managed lions across the State.  These new monitoring and modeling methods will enable FWP to fully implement an adaptive harvest management program through which population objectives are set, management alternatives are objectively evaluated, a preferred harvest prescription is applied, the effect of that harvest is directly monitored over time, and management is adjusted based on new information and changing objectives. FWP believes that this strategy will help reduce contention among stakeholders, optimize harvest and pursuit opportunity, reduce conflicts, and ensure that robust lion populations are conserved across their Montana habitats

Approaches Initiated to Gain Insight into Respiratory Disease in Montana’s Bighorn Sheep Herds

Respiratory disease is a major limiting factor in the restoration, conservation, and management of bighorn sheep in Montana and throughout western North America. Despite many decades of research there is a limited understanding of the disease process, with proactive management to minimize disease primarily limited to establishing policies to minimize exposure of bighorn sheep to domestic sheep. In the past decade, however, there have been significant advances in understanding the pathogens involved in bighorn sheep pneumonia that have resulted in the development of new sampling and testing methodologies that promise to advance our understanding of the disease.  This presentation will review the general ideas regarding the pathogens and the disease process advanced by leading researchers of bighorn sheep pneumonia and describe how these ideas are being combined with recent sampling and testing advances and incorporated into Montana’s state-wide bighorn sheep research program. We will also describe the collaborations developed between our research team and other research teams addressing the same questions in neighboring states. These collaborations are an attempt to build a regional initiative that combines the resources, expertise, and unique management histories of bighorn herds in other states. We think such open communication and coordination of research activities will help us advance our understanding of bighorn sheep pneumonia and develop management strategies that can enhance restoration of the species

Linking Landscape-Scale Differences in Forage to Ungulate Nutritional Ecology

Understanding how habitat and nutritional condition affect ungulate populations is necessary for informing management, particularly in areas experiencing carnivore recovery and declining ungulate population trends.  Variations in forage species availability, plant phenological stage, and the abundance of forage make it challenging to understand landscape-level effects of nutrition on ungulates.  We developed an integrated spatial modeling approach to estimate landscape-level elk (Cervus elaphus) forage quality in two adjacent study areas that differed in coarse measures of habitat quality and related the consequences of differences in forage quality to elk body condition and pregnancy rates.  We found no support for differences in dry matter digestibility between plant samples or in phenological stage based on ground sampling plots in the two study areas.  Forage quality, measured as digestible forage biomass, varied among land cover types and between study areas. We found that altered plant composition following fires was the biggest driver of forage quality differences, suggesting that maintaining a mosaic of fire history and distribution will likely benefit ungulate populations.  Study area, lactation status and year affected fall body fat of adult female elk.  Elk in the study area exposed to lower quality summer range forage had lower nutritional condition entering winter.  These differences in nutritional condition resulted in differences in pregnancy rate, with average pregnancy rates of 89% for elk exposed to higher quality forage and 72% for elk exposed to lower quality forage.  Summer range forage quality has the potential to limit elk pregnancy rate and calf production, and these nutritional limitations may predispose elk to be more sensitive to the effects of harvest or predation.  Wildlife managers should identify ungulate populations that are nutritionally limited and recognize that these populations may be more impacted by recovering carnivores or harvest than populations inhabiting more productive summer habitats

Effects of Hunter Access on Hunting Season Elk Distributions in the Missouri River Breaks

Increasing harvest of adult female elk (Cervus elaphus nelsoni) is the primary management tool for curtailing elk population growth and reducing elk populations. However, this tool is not effective when elk are located on private properties that restrict hunter access to elk during the hunting season. The purpose of this project was to evaluate the effects of hunter access and other landscape factors on elk resource selection during the archery and rifle hunting seasons in the Missouri River Breaks area. We sampled 46 adult female elk for 2-years in 2 adjacent populations: the Missouri River Breaks (MRB) population and the Larb Hills population. The MRB archery and rifle season elk population ranges were 97% accessible to hunters. Several large properties in the center of the Larb Hills range restricted or did not allow hunter access, and the archery and rifle season elk population ranges were 79% accessible to hunters. To quantify the effects of hunter access and other factors on elk selection of home ranges and elk selection of locations within their home range, we conducted a resource selection modeling exercise. Second-order population-level selection coefficients showed that elk in both MRB and Larb Hills selected home ranges in areas with no hunter access, and hunter access was the strongest predictor of second-order selection. Similarly, third-order population-level selection coefficients showed elk in both populations selected locations within their seasonal home range with no hunter access, and the strength of selection for locations with no hunter access was stronger in the archery season than the rifle season. However, individual models revealed that although third-order population-level selection for no hunter access was strong, only 43% of MRB elk selected for no hunter access during the archery season and 18% of elk selected for no hunter access during the rifle season. Additionally, the majority of all MRB elk locations (i.e., 68% of archery locations and 91% of rifle locations) occurred in areas accessible to hunters. In Larb Hills, individual models confirmed results of the population-level analysis, and 76% and 60% of elk selected for locations with no hunter access during the archery and rifle seasons. Even if hunter access is restricted or in a relatively small geographic area within an elk population range, elk refuge situations may have a disproportionate affect on elk distributions and prevent effective harvest of female elk to maintain elk populations at objective levels. Working cooperatively with stakeholders to minimize these situations is necessary for curtailing further elk population increases and maintaining a distribution of elk across public and private lands. If elk refuge situations cannot be resolved, stakeholders may need to choose between allowing some level of hunter access to harvest female elk or accepting higher numbers of elk, and associated property damage issues

Assessing Brucellosis Seroprevalence and Transmission Risk in a Free-Ranging Elk Population: The Targetted Brucellosis Surveillance Project in Montana

Brucellosis is a bacterial disease that affects elk, bison and domestic cattle.  Recently the seroprevalence of brucellosis in free-ranging elk populations of Montana has increased and its’ range has expanded, resulting in increased pressure on Montana Fish, Wildlife and Parks (MFWP) to manage the disease in elk.  In 2010 MFWP and the Montana Department of Livestock initiated a targeted surveillance program to delineate the current geographic distribution of brucellosis, document spatio-temporal habitat selection and movement patterns, and to quantify potential transmission risk from elk to cattle.  Since 2010, we have targeted 11 different winter ranges from 9 hunt districts, both within and outside of the Designated Surveillance Area used to manage cattle.  During each capture operation we tested approximately 100 adult female elk for exposure to brucellosis.  We deployed GPS radiocollars on a subsample of adult female elk on each winter range.  An epidemiological summary of the first five years, including seroprevalence, movement and implications for transmission vectors will be presented. Current brucellosis exposure in domestic herds, future surveillance areas, evaluation of various management actions on transmission risk, and the creation of a spatio-temporal risk model are discussed

Evaluating Bottom-Up and Top-Down Effects on Elk Survival and Recruitment: Year Two Update of a Case Study in the Bitterroot Valley

Understanding the contribution of recruitment to population growth rate in ungulates is a fundamental challenge to wildlife managers attempting to integrate carnivore and ungulate management. Like much of western Montana, in the Bitterroot Valley, the decline of elk (Cervus elaphus) populations and calf recruitment occurred concurrently with wolf (Canis lupus) recovery. However, a multitude of abiotic, bottom-up and top-down factors likely affect recruitment rates. We studied cause-specific mortality of elk calves to understand the role of competing mortality risk on calf recruitment in the East Fork and West Fork of the Bitterroot Valley, Montana. A total of 66 and 76 neonatal elk calves were captured in spring 2011 and 2012, respectively, and an additional 31 and 29 6-month-olds in late November 2011 and 2012. We analyzed calf survival using a Weibull parametric survival model, and cause-specific mortality using cumulative incidence functions. Preliminary analyses for the first 20 months of the research indicate mountain lions as the leading cause of mortality for elk calves during both summer and winter. We are also evaluating the role of summer forage resources on maternal condition, calf birth weights and survival. Preliminary results from nutritional work suggest potential bottom-up differences influencing resilience of elk populations to top-down predation. Our study fills a critical knowledge gap regarding the role of summer vs winter mortality in elk and the role of nutrition. The study will complement previous studies and help wildlife managers integrate carnivore and ungulate management across western Montana following carnivore recovery