Fig 1 - uploaded by Kelley M Stewart
Content may be subject to copyright.
Map displaying the migration route and seasonal ranges used by mule deer that migrated through the Bald Mountain mine complex in the Ruby Mountains of eastern Nevada, USA, January 2012 through February 2014. White circles indicate winter ranges, grey circle indicates summer range, and the black shaded area indicates extent of the migration pathway from summed BBMM.
Source publication
Loss of migratory corridors has been identified as an important ecological issue among species that exhibit long-distance migration worldwide. Increased mineral exploration and development has raised the level of concern over the protection of terrestrial migration routes for ungulates. Mineral exploration and other types of development may adverse...
Contexts in source publication
Context 1
... ( Lynx rufus ). Similar to other mountain ranges within the Great Basin, low elevations are dominated by a variety of shrub species including several species of sagebrush ( Artemisia tridentata ), antelope bitterbrush ( Purshia tridentata ), and Utah juniper ( Juniperus osteosperma ). Middle to high elevations are dominated by quaking aspen ( Populus tremuloides ), singleleaf pinyon pine ( Pinus monophylla ), Utah juniper, green rabbit- brush ( Chrysothamnus viscidiflorus ), and Utah serviceberry ( Amelanchier utahensis ). The Ruby Mountains contain a large amount of free standing water sources compared with other Great Basin ranges, including alpine lakes, springs, streams, and water developments for wildlife. Bald Mountain, at the southern end of the Ruby Mountains, has been mined for gold since about 1980 and the Bald Mountain mine is currently owned by Barrick Gold Corporation Inc. (Barrick). The Bald Mountain mine is located in the southern Ruby Mountains ; 57 km northeast of Eureka, NV (Latitude: 39.938458 8 , Longitude: À 115.564516 8 ). Mule deer that travel through Bald Mountain mine use the Ruby Butte area (northern Ruby Mountains) as their tradi- tional summer range and both Buck and Antelope Mountains, ; 25 and ; 54 km south of Bald Mountain mine, as their primary winter ranges; the full extent of the migratory corridor is ; 130 km ( Fig. 1). The Bald Mountain mine is divided into two main operation areas, the North Operations Area (NOA) and the South Operations Area (SOA). The two sites vary consider- ably in the amount of disturbance that occupies the landscape with the NOA ’ s total authorized disturbance (as of the 2009 BLM Record of Decision) at ; 3,700 ha and the SOA ’ s total authorized disturbance at ; 400 ha. The NOA is ; 23 km east to west and ; 19 km north to south at its widest point and is located in the center of a major migration corridor for mule deer (Fig. 1). Although this portion of the mine is subject to a large amount of surface disturbance, there is a large amount of undisturbed habitat within its borders that mule deer may utilize as a refuge from both direct and indirect disturbances. None of our study animals migrated within 4 km of the SOA throughout the duration of our project, thus we focused our efforts on the NOA. Those operation areas contain a wide variety of disturbance types including open pits, rock disposal areas (RDAs), heap leach facilities (HLFs), offices, growth media stockpiles, sanita- tion facilities, material storage areas, haul roads (equivalent to a four-lane highway), exploration roads (generally two track or gravel roads), and exploration pads. To clarify those terms, growth media stockpiles can be described as stockpiles of material that will be used as the uppermost cover layer during reclamation processes due to its qualities that are conducive for supporting vegetation (M. Maples, personal communication ). A heap leach facility or pad is an area of substrate where sprinklers disperse a leaching solvent (acid or cyanide) that dissolves the metals in the substrate and they collect at the bottom of the pad. The total area of the surface disturbances varies primarily according to type with HLFs ( ; 2 to ; 166 ha), RDAs ( ; 1 to ; 81 ha) and open pits ( ; 1 to ; 93 ha) comprising the largest surface disturbances and exploration pads ( ; 0.08 ha) encompassing the smallest surface disturbance. Operations related to mineral exploration and extraction within the mine complex proceed 24 hours a day. We captured adult ( ! 1 year) female mule deer using a net gun fired from a helicopter (Krausman et al. 1985) in and around the NOA of the Bald Mountain mine complex, Buck Mountain, and Antelope Mountain in 2012 ( n 1⁄4 12) and 2013 ( n 1⁄4 30). We attempted to capture only one individual from each group of deer to maintain independence of sampling units (Zar 2010). Mule deer were fitted with Advanced Telemetry Systems Iridium/GPS collars (G2110E, Advanced Telemetry Systems, Isanti, Minnesota, USA) programmed to collect a location every hour from October 1 through April 30 and 1 location per day from May 1 through September 30. We chose those time periods based on timing of migration in the Ruby Mountains, because our objective was to obtain fine-scaled movement data during migration periods. We obtained data from GPS collars by retrieval of remotely downloaded data. We tested collars for fix-rate bias and removed all collars with low fix ...
Context 2
... ( Lynx rufus ). Similar to other mountain ranges within the Great Basin, low elevations are dominated by a variety of shrub species including several species of sagebrush ( Artemisia tridentata ), antelope bitterbrush ( Purshia tridentata ), and Utah juniper ( Juniperus osteosperma ). Middle to high elevations are dominated by quaking aspen ( Populus tremuloides ), singleleaf pinyon pine ( Pinus monophylla ), Utah juniper, green rabbit- brush ( Chrysothamnus viscidiflorus ), and Utah serviceberry ( Amelanchier utahensis ). The Ruby Mountains contain a large amount of free standing water sources compared with other Great Basin ranges, including alpine lakes, springs, streams, and water developments for wildlife. Bald Mountain, at the southern end of the Ruby Mountains, has been mined for gold since about 1980 and the Bald Mountain mine is currently owned by Barrick Gold Corporation Inc. (Barrick). The Bald Mountain mine is located in the southern Ruby Mountains ; 57 km northeast of Eureka, NV (Latitude: 39.938458 8 , Longitude: À 115.564516 8 ). Mule deer that travel through Bald Mountain mine use the Ruby Butte area (northern Ruby Mountains) as their tradi- tional summer range and both Buck and Antelope Mountains, ; 25 and ; 54 km south of Bald Mountain mine, as their primary winter ranges; the full extent of the migratory corridor is ; 130 km ( Fig. 1). The Bald Mountain mine is divided into two main operation areas, the North Operations Area (NOA) and the South Operations Area (SOA). The two sites vary consider- ably in the amount of disturbance that occupies the landscape with the NOA ’ s total authorized disturbance (as of the 2009 BLM Record of Decision) at ; 3,700 ha and the SOA ’ s total authorized disturbance at ; 400 ha. The NOA is ; 23 km east to west and ; 19 km north to south at its widest point and is located in the center of a major migration corridor for mule deer (Fig. 1). Although this portion of the mine is subject to a large amount of surface disturbance, there is a large amount of undisturbed habitat within its borders that mule deer may utilize as a refuge from both direct and indirect disturbances. None of our study animals migrated within 4 km of the SOA throughout the duration of our project, thus we focused our efforts on the NOA. Those operation areas contain a wide variety of disturbance types including open pits, rock disposal areas (RDAs), heap leach facilities (HLFs), offices, growth media stockpiles, sanita- tion facilities, material storage areas, haul roads (equivalent to a four-lane highway), exploration roads (generally two track or gravel roads), and exploration pads. To clarify those terms, growth media stockpiles can be described as stockpiles of material that will be used as the uppermost cover layer during reclamation processes due to its qualities that are conducive for supporting vegetation (M. Maples, personal communication ). A heap leach facility or pad is an area of substrate where sprinklers disperse a leaching solvent (acid or cyanide) that dissolves the metals in the substrate and they collect at the bottom of the pad. The total area of the surface disturbances varies primarily according to type with HLFs ( ; 2 to ; 166 ha), RDAs ( ; 1 to ; 81 ha) and open pits ( ; 1 to ; 93 ha) comprising the largest surface disturbances and exploration pads ( ; 0.08 ha) encompassing the smallest surface disturbance. Operations related to mineral exploration and extraction within the mine complex proceed 24 hours a day. We captured adult ( ! 1 year) female mule deer using a net gun fired from a helicopter (Krausman et al. 1985) in and around the NOA of the Bald Mountain mine complex, Buck Mountain, and Antelope Mountain in 2012 ( n 1⁄4 12) and 2013 ( n 1⁄4 30). We attempted to capture only one individual from each group of deer to maintain independence of sampling units (Zar 2010). Mule deer were fitted with Advanced Telemetry Systems Iridium/GPS collars (G2110E, Advanced Telemetry Systems, Isanti, Minnesota, USA) programmed to collect a location every hour from October 1 through April 30 and 1 location per day from May 1 through September 30. We chose those time periods based on timing of migration in the Ruby Mountains, because our objective was to obtain fine-scaled movement data during migration periods. We obtained data from GPS collars by retrieval of remotely downloaded data. We tested collars for fix-rate bias and removed all collars with low fix ...
Citations
... Mining and other anthropogenic factors have direct and indirect effects on ungulates. Direct loss is defined as the loss of any habitat or individual as a result of development within wildlife habitats (Blum et al., 2015). For example, the construction of a mine directly reduces the availability of habitats for terrestrial migrants and can increase the risk of mortality as a result of higher levels of human activity (Blum et al., 2015). ...
... Direct loss is defined as the loss of any habitat or individual as a result of development within wildlife habitats (Blum et al., 2015). For example, the construction of a mine directly reduces the availability of habitats for terrestrial migrants and can increase the risk of mortality as a result of higher levels of human activity (Blum et al., 2015). Indirect loss is defined as any change in behaviour or habitat use as a result of disturbances (Blum et al., 2015). ...
... For example, the construction of a mine directly reduces the availability of habitats for terrestrial migrants and can increase the risk of mortality as a result of higher levels of human activity (Blum et al., 2015). Indirect loss is defined as any change in behaviour or habitat use as a result of disturbances (Blum et al., 2015). For example, mule deer (Odocoileus hemionus) are less likely to use areas with high noise levels or high volumes of traffic (Sawyer et al., 2009). ...
... Indeed, habitat loss resulting from anthropogenic development has been described as the single most important impact on wildlife today (Barnosky et al., 2011;Drolet et al., 2016). Those developments include gas and oil extraction (Sawyer et al., 2006;Sawyer et al., 2009;Lendrum et al., 2012;Christie et al., 2017), mining for minerals and precious metals (Boulanger et al., 2012;Blum et al., 2015), residential development (Polfus and Krausman, 2012;Johnson et al., 2017;Wyckoff et al., 2018), fencing (Xu et al., 2021), and alternative energy (Lovich and Ennen, 2011;Agha et al., 2020;Sawyer et al., 2022). Anthropogenic structures fragment habitat and reduce both availability and quality of habitat and for wildlife populations. ...
... Anthropogenic structures fragment habitat and reduce both availability and quality of habitat and for wildlife populations. Energy development and mining for minerals and other natural resources has been rapidly expanding across the Western United States over the past several decades (Beckmann et al., 2012;Blum et al., 2015;Martins-Oliveira et al., 2021). Although human developments are increasing across the landscape, our understanding of the corresponding effects on wildlife populations and their habitats, especially from large-scale mining, is limited (Blum et al., 2015, Martins-Oliveira et al., 2021. ...
... Energy development and mining for minerals and other natural resources has been rapidly expanding across the Western United States over the past several decades (Beckmann et al., 2012;Blum et al., 2015;Martins-Oliveira et al., 2021). Although human developments are increasing across the landscape, our understanding of the corresponding effects on wildlife populations and their habitats, especially from large-scale mining, is limited (Blum et al., 2015, Martins-Oliveira et al., 2021. ...
... Humans directly alter wildlife behavior through top-down forces such as hunting (Ciuti et al., 2012;Hertel et al., 2016;Lone et al., 2015), and through less invasive activities such as hiking and ecotourism (Coppes et al., 2017;Larm et al., 2021). Indirect effects of humans on wildlife behavior can also occur through physical alterations to the environment, such as anthropogenic noise and light pollution (Sanders et al., 2021;Shannon et al., 2016), residential development (Wang et al., 2017), and resource extraction practices (Blum et al., 2015;Johns, 1986). These forces, in turn, alter wildlife behavioral traits (Doherty et al., 2021;Sih et al., 2011;Wilson et al., 2020). ...
Humans are increasingly recognized as important players in predator–prey dynamics by modifying landscapes. This trend has been well‐documented for large mammal communities in North American boreal forests: logging creates early seral forests that benefit ungulates such as white‐tailed deer (Odocoileus virginianus), while the combination of infrastructure development and resource extraction practices generate linear features that allow predators such as wolves (Canis lupus) to travel and forage more efficiently throughout the landscape. Disturbances from recreational activities and residential development are other major sources of human activity in boreal ecosystems that may further alter wolf–ungulate dynamics. Here, we evaluate the influence that several major types of anthropogenic landscape modifications (timber harvest, linear features, and residential infrastructure) have on where and how wolves hunt ungulate neonates in a southern boreal forest ecosystem in Minnesota, USA. We demonstrate that each major anthropogenic disturbance significantly influences wolf predation of white‐tailed deer fawns (n = 427 kill sites). In contrast with the “human shield hypothesis” that posits prey use human‐modified areas as refuge, wolves killed fawns closer to residential buildings than expected based on spatial availability. Fawns were also killed within recently‐logged areas more than expected. Concealment cover was higher at kill sites than random sites, suggesting wolves use senses other than vision, probably olfaction, to detect hidden fawns. Wolves showed strong selection for hunting along linear features, and kill sites were also closer to linear features than expected. We hypothesize that linear features facilitated wolf predation on fawns by allowing wolves to travel efficiently among high‐quality prey patches (recently logged areas, near buildings), and also increase encounter rates with olfactory cues that allow them to detect hidden fawns. These findings provide novel insight into the strategies predators use to hunt ungulate neonates and the many ways human activity alters wolf–ungulate neonate predator–prey dynamics, which have remained elusive due to the challenges of locating sites where predators kill small prey. Our research has important management and conservation implications for wolf–ungulate systems subjected to anthropogenic pressures, particularly as the range of overlap between wolves and deer expands and appears to be altering food web dynamics in boreal ecosystems.
... Mule deer are a species of conservation concern because of their once ubiquitous distribution in the western United States and more recently, range-wide population declines (Bergman et al. 2015;Johnson et al. 2017). Of particular concern are losses to mule deer habitat through fragmentation and impacts to migration corridors (Berger 2004;Sawyer et al. 2009;Bergman et al. 2015;Blum et al. 2015). Additionally, a recent study on sage-grouse (Centrocerus urophasianus), an important species of conservation concern, indicated crucial conservation areas for sage grouse overlapped winter ranges of mule deer by 52-91% and migration corridors by 66-77% (Copeland et al. 2014). ...
... We estimated resource selection functions (RSFs) with a use-availability design for mule deer locations within a general resource selection framework for telemetry data (Johnson et al. 2006). We generated RSFs by fitting generalized linear mixed-effects models with a binomial error distribution and logit link function using the "lme4" package in program R (Johnson et al. 2006;Blum et al. 2015;McKee et al. 2015). To develop RSFs we chose variables known to be important habitat components for mule deer (Pierce et al. 2004;Blum et al. 2015;McKee et al. 2015) including vegetation class, slope (%), aspect [sine (east-west) and cosine (north-south)], elevation (m), terrain ruggedness (Sappington et al. 2007), distance to water (m), and distance to the elk release site (m). ...
... We generated RSFs by fitting generalized linear mixed-effects models with a binomial error distribution and logit link function using the "lme4" package in program R (Johnson et al. 2006;Blum et al. 2015;McKee et al. 2015). To develop RSFs we chose variables known to be important habitat components for mule deer (Pierce et al. 2004;Blum et al. 2015;McKee et al. 2015) including vegetation class, slope (%), aspect [sine (east-west) and cosine (north-south)], elevation (m), terrain ruggedness (Sappington et al. 2007), distance to water (m), and distance to the elk release site (m). We standardized all continuous variables using the 'scale' function in program R, which allowed for direct comparisons of effect sizes of parameter estimates (Boyce 2006). ...
Translocation of animals for conservation has a long history of successes and failures since humans began intervening with species distributions in the early part of the 20th century. Effects of translocations on other species occupying the area of introduction are rarely considered in species management plans. We hypothesized that the introduction of a large-bodied ungulate, Rocky Mountain elk (Cervus canadensis nelsoni), would cause a shift in the spatial distribution and winter habitat selection of a smaller-bodied ungulate, Rocky Mountain mule deer (Odocoileus hemionus hemionus), already occupying the study area in northeastern Nevada. We examined mule deer survey locations during an 8-year time interval from 1993 to 2001 to test hypotheses related to potential competition with or displacement of mule deer following introduction of elk in 1997. We used geospatial statistics to quantify changes in seasonal distributions of mule deer and a resource selection function (RSF) framework to model changes in selection of resources by mule deer before and after elk were translocated into our study area. Our results indicated that mule deer exhibited a shift in their core distribution by approximately 5.72 km after the introduction of elk. Mule deer changed their use of habitat by selecting shallower slopes, more north-facing aspects, and areas farther from the elk release site, where most of the elk congregated. Mule deer selected habitats with more pinyon-juniper tree cover and mixed shrublands prior to the elk translocation, indicating a potential tradeoff in thermal cover and forage quality. This research is one of the few empirical studies to describe competitive interactions between elk and mule deer on a shared winter range in North America. Implications of this research have importance for managers concerned with restoring communities to their native conditions especially where the potential for competition with non-indigenous species or other competing species with similar niche requirements exists.
... The juxtaposition of steep slopes with abrupt ecotones supporting early successional plant communities attracts ungulate prey. Indeed, the use of mined landscapes by three of the most important ungulate prey for cougars has been widely reported, and suggests that rehabilitated sites away from active excavation can be important habitat for mountain ungulates (Olsson et al. 2007;Bleich et al. 2009;Blum et al. 2015). Second, the use of mined areas may indicate presence of an abundant, energetically rewarding alternative prey species, such as marmots (Marmota flaviventris: e.g., Branch et al. 1996). ...
Western North America is experiencing remarkable human population growth and land-use change. Irrigation and associated cultivation have led to colonization of urban-wildland interface (UWI) environments by mule deer (Odocoileus hemionus), and consequently, cougars (Puma concolor). In the wake of these changes, human-wildlife conflicts have increased in tandem with questions about long-term species conservation. To address these concerns, we fit 79 cougars with radio-telemetry collars in the Oquirrh Mountains near Salt Lake City, Utah (2002–2010). Our goal was to evaluate variation in cougar habitat selection, diet, and cause-specific mortality in a landscape dominated by urban, military, and industrial activities. We used radio-telemetry data in concert with Resource Selection Functions to address three hypotheses: (1) that cougars would select wildland over UWI land-uses; (2) prey composition would reflect differences in land-use; and (3) mortality would be predominantly human-caused. Cougars largely selected wildland habitats associated with seasonal mule deer presence, but contrary to expectation, they also selected habitats closer to urban and mined areas. Prey composition in the UWI did not differ from wildland habitats. Domestic ungulates represented only 2% of 540 recovered prey items and were found primarily in wildlands. Native ungulates comprised > 90% of the total kill, irrespective of season or land-use, suggesting that use of UWI habitats was linked to mule deer presence. Cougar mortality was disproportionately due to natural causes in wildlands, but individuals that died of human causes in UWI habitats were more likely to be inexperienced hunters, supporting young kittens, or compromised by physical handicaps. In general, presence of mule deer was the key predictor of cougar habitat use, even in this highly disturbed, anthropogenically altered landscape. As such, management designed to reduce conflict and ensure conservation will need to focus on urban deer, land-use planning, and targeted education campaigns to reduce food subsidies.
... Recognizing that migratory behavior decreases as disturbance increases adds to a growing body of knowledge of how development affects ungulate migration (Lendrum et al. 2012(Lendrum et al. , 2013Sawyer et al. 2013;Blum et al. 2015;Wyckoff et al. 2018). In practice, however, managers would benefit from knowing the threshold at which surface disturbance becomes problematic, to better balance competing land uses like energy development and wildlife habitat protection. ...
Fine‐scale movement data has transformed our knowledge of ungulate migration ecology and now provides accurate, spatially explicit maps of migratory routes that can inform planning and management at local, state, and federal levels. Among the most challenging land use planning issues has been developing energy resources on public lands that overlap with important ungulate habitat, including the migratory routes of mule deer ( Odocoileus hemionus ). We generally know that less development is better for minimizing negative effects and maintaining habitat function, but we lack information on the amount of disturbance that animals can tolerate before reducing use of or abandoning migratory habitat. We used global positioning system data from 56 deer across 15 years to evaluate how surface disturbance from natural gas well pads and access roads in western Wyoming, USA, affected habitat selection of mule deer during migration and whether any disturbance threshold(s) existed beyond which use of migratory habitat declined. We used resource and step selection functions to examine disturbance thresholds at 3 different spatial scales. Overall, migratory use by mule deer declined as surface disturbance increased. Based on the weight of evidence from our 3 independent but complementary metrics, declines in migratory use related to surface disturbance were non‐linear, where migratory use sharply declined when surface disturbance from energy development exceeded 3%. Disturbance thresholds may vary across regions, species, or migratory habitats (e.g., stopover sites). Such information can help with management and land use decisions related to mineral leasing and energy development that overlap with the migratory routes of ungulates. © 2020 The Wildlife Society.
... For example, some route segments are used primarily for movement (i.e., movement corridors), whereas in other route segments, forward movement slows to remain in sync with vegetation phenology as those areas (i.e., stopover sites) are used for extending foraging bouts (Sawyer and Kauffman 2011). Other functional attributes such as parturition areas or security habitat exist for some migrations, but movement corridors and stopovers are common among ungulates that migrate long distances (>50 km; White et al. 2010, Monteith et al. 2011, Sawyer and Kauffman 2011, Blum et al. 2015. Previous research has revealed that mule deer synchronize their initiation (Monteith et al. 2011, Lendrum et al. 2013) and movement Kauffman 2011, Aikens et al. 2017) during migration to correspond with plant phenology, which allows individuals to exploit young, protein-rich plants that are highly digestible (Albon and Langvatn 1992, Lendrum et al. 2014, Merkle et al. 2016. ...
... Avoidance of anthropogenic disturbance is common among most large herbivores (Wasser et al. 2011, Webb et al. 2011, Beckmann et al. 2012 and is particularly well documented in mule deer (Sawyer et al. 2006, 2017, Lendrum et al. 2012, Blum et al. 2015. We expected selection of Notes: Models were evaluated based on Akaike's Information Criterion adjusted for small sample size (AIC c ), DAIC c , and log likelihood; we also provide the number of parameters (K) for each model. ...
... Although some large terrestrial herbivores do not use stopovers on their migrations and do not remain in synchrony with a wave of vegetation green up (Bischof et al. 2012, Lendrum et al. 2013, stopovers appear to be especially common in large herbivores that migrate long distances (>50 km; White et al. 2010, Monteith et al. 2011, Sawyer and Kauffman 2011, Sawyer et al. 2013, Blum et al. 2015, Skarin et al. 2015, which may underscore their importance in sustaining long-distance migrations. Selection for migratory corridors was linked poorly with emerging forage associated with spring green-up, and in the instance of the Atlantic Rim study area, it was associated with sites with delayed vegetation phenology (Fig. 3). ...
Long‐distance migration by terrestrial mammals is a phenomenon critical to the persistence of populations, but such migrations are declining globally because of over‐harvest, habitat loss, and movement barriers. Increasingly, there is a need to improve existing routes, mitigate route segments affected by anthropogenic disturbance, and in some instances, determine whether alternative routes are available. Using a hypothesis‐driven approach, we identified landscape features associated with the primary functional attributes, stopovers and movement corridors, of spring migratory routes for mule deer in two study areas using resource selection functions. Patterns of selection for landscape attributes of movement corridors and stopovers mostly were similar; however, landscape features associated with movement corridors aligned better with areas that facilitated movement, whereas selection of stopovers was consistent with sites offering early access to spring forage. For movement corridors, deer selected for dry sites, low elevation, and low anthropogenic disturbance. For stopovers, deer selected for dry sites, with consistently early green‐up across years, south‐southwesterly aspects, low elevation, and low anthropogenic disturbance. Stopovers and movement corridors of a migratory route presumably promote different functions, but for a terrestrial migrant, patterns of habitat selection indicate that the same general habitat attributes may facilitate both movement and foraging in spring. Our findings emphasize the roles of topographical wetness, vegetation phenology, and anthropogenic disturbance in shaping use of the landscape during migration for this large herbivore. Avoiding human disturbance and tracking ephemeral forage resources appear to be a consistent pattern during migration, which reinforces the notion that movement during migration has a nutritional underpinning and disturbance potentially alters the net benefits of migration.
... Movement rates have been used to determine post-capture recovery time (Quinn et al. 2012). We used GPS data from collars to calculate average daily movement rates (m/hr) based on distance moved and time between successive locations (Blum et al. 2015) for adult cougars released from bobcat traps, and those captured using trained hounds. We included only the first capture occasion of cougars as an adult, and excluded those that died of any cause within 60 days of capture from analysis. ...
Cougars (Puma concolor) occupy mountain ranges throughout the Great Basin, Nevada, USA, where legal trapping of bobcats (Lynx rufus) is common and some non‐target captures of cougars in bobcat traps occur. Such incidental capture of cougars is an undocumented source of mortality because some cougars die from injuries several weeks after release from traps. We examined cause‐specific mortality and the effects of capture of cougars in bobcat traps on annual and overall (7‐year) survival during 2009–2015. We captured 48 cougars, of which we followed 33 until death. We estimated average annual survival rates for adult cougars and assessed the relative effects of sex, season, and long‐term effects of non‐target capture of cougars in foothold traps on estimated survival of adults using a nest survival model in Program MARK. We incorporated a time‐varying covariate to assess the long‐term effect of capture in non‐target foothold traps on survival of adult cougars. Average annual survival of non‐trapped females and males, regardless of trapping history, was significantly greater than females with a history of capture in a non‐target foothold trap; however, once partitioned across age, sex, and capture status, sample sizes were small. Our results suggest that capture in non‐target foothold traps decreases survival of adult female cougars directly by causing injuries that eventually result in mortality, and indirectly by increasing susceptibility to other forms of mortality. Mortality of adult females during the 7 years of our study caused by non‐target trapping was similar to hunting among radio‐marked female cougars, and this potential source of mortality has been unaccounted for in harvest objectives and harvest data for cougars without radio‐collars. Given anthropogenic sources of mortality accounted for 100% of recorded mortality of adult females, mortality from non‐target trapping is likely additive to other sources of mortality in our study area. We recommend regulatory agencies consider the possibility of unintentional take and potential for reduced long‐term survival of females where these large fields are sympatric with bobcats, and trapping of bobcats with foothold traps is a legal activity. Moreover, we suggest wildlife managers record information about the trapping incident, to include trap type, trap size, trap set type, location, number of days since last check, and type and severity of injuries when releasing incidentally captured cougars to inform future management decisions. Addressing other anthropogenic sources of mortality resulting from conflict with humans and road mortalities will be increasingly important as the human population expands into cougar habitat. © 2018 The Wildlife Society.
... Fix schedules for GPS locations were collected at 1-day intervals (if more fixes were recorded, we randomly sampled a single fix per day) while animals were on summer and winter ranges. GPS locations recorded during seasonal migration events (migration start and end dates were determined following Blum, Stewart, & Schroeder, 2015) were excluded from further analysis; all remaining GPS locations were assumed to belong to either the summer or winter range. ...
Resource selection functions (RSFs) are tremendously valuable for ecologists and resource managers because they quantify spatial patterns in resource utilization by wildlife, thereby facilitating identification of critical habitat areas and characterizing specific habitat features that are selected or avoided. RSFs discriminate between known-use resource units (e.g., telemetry locations) and available (or randomly selected) resource units based on an array of environmental features, and in their standard form are performed using logistic regression. As generalized linear models, standard RSFs have some notable limitations, such as difficulties in accommodating nonlinear (e.g., humped or threshold) relationships and complex interactions. Increasingly, ecologists are using flexible machine-learning methods (e.g., random forests, neural networks) to overcome these limitations. Herein, we investigate the seasonal resource selection patterns of mule deer (Odocoileus hemionus) by comparing a logistic regression framework with random forest (RF), a popular machine-learning algorithm. Random forest (RF) models detected nonlinear relationships (e.g., optimal ranges for slope and elevation) and complex interactions which would have been very challenging to discover and characterize using standard model-based approaches. Compared with standard RSF models, RF models exhibited improved predictive skill, provided novel insights about resource selection patterns of mule deer, and, when projected across a relevant geographic space, manifested notable differences in predicted habitat suitability. We recommend that wildlife researchers harness the strengths of machine-learning tools like RF in addition to “classical” tools (e.g., mixed-effects logistic regression) for evaluating resource selection, especially in cases where extensive telemetry data sets are available.
... Expanding energy development is projected to result in N 200 000 km 2 of land utilized by various forms of energy development in the United States by 2035 (McDonald et al. 2009). Impacts from anthropogenic development can negatively affect mule deer use of winter ranges (Sawyer et al. 2006), migration routes (Sawyer et al. 2009a;Lendrum et al. 2013;Sawyer et al. 2013), and other seasonal habitats (Blum et al. 2015). Similar avoidance of human activity has been observed with other ungulate species including elk (Cervus elaphus; Kuck et al. 1985;Buchanan et al. 2014), pronghorn (Antilocapra americana; Beckman et al. 2012), and caribou (Rangifer tarandus ssp.; Cameron et al. 2005;Sorensen et al. 2007;Polfus et al. 2011) that inhabit areas with mining, oil and gas development, or other human-associated infrastructure. ...
... Mule deer avoided oil and gas infrastructure out to 600-800 m in a study evaluating use of shale oil and gas development in northwestern Colorado (Northrup et al. 2015). Mule deer avoided areas of higher disturbance within mine complexes spending more time within less disturbed areas in southwestern Idaho (Blum et al. 2015). Such changes in wintering and migratory behavior may ultimately influence mule deer survival. ...
Anthropogenic development impacts habitat use by many rangeland species including mule deer (Odocoileus hemionus). Recent policies, including Wyoming’s Sage-Grouse Executive Order, have been implemented to conserve habitat and populations of greater sage-grouse (Centrocercus urophasianus). Core Areas (CAs), designated for sage-grouse conservation by the Wyoming policy, are likely less disturbed than non − CA, predictably providing protection for nontarget species, such as mule deer, that share substantial habitat with sage-grouse. Our objectives focused on examining the influence of Wyoming’s CAs on mule deer including 1) quantifying oil and gas development within crucial winter range and Hunt Areas (HAs) with respect to CA overlap and 2) using fawn-to-female ratios (fawns · 1 adult female–1) to evaluate whether deer populations overlapping CAs were more productive. We used oil and gas well data from the Wyoming Oil and Gas Conservation Commission and fawn-to-female ratios for 103 mule deer HAs derived from Wyoming Game and Fish Department data across designated mule deer crucial winter ranges (1980–2013) and statewide mule deer HAs (1995–2013). Numbers and trends in well pads were lower within CA-overlapped deer winter range than non − CA-overlapped winter ranges during 1980–2013. Mule deer HAs overlapped by CAs also displayed lower trends of well pads as the percentage of CA overlap increased. Trend in fawn-to-female ratios (mean = 0.69, range: 0.55–0.83) was higher in HAs with ≥ 70% CA overlap compared with a slight but significant negative trend in fawn-to-female ratios (mean = 0.64, range: 0.53–0.73) in HAs with no CA overlap (≤ 1%) from 1995–2013. HAs with CA overlap ≥ 70% exceeded 0.66 fawns-to-female, a threshold indicative of an increasing population. The relative change in fawn-to-female ratios has important implications to conservation of mule deer populations.
