Supporting Science and Research

Over the years, your support has made possible a wealth of scholarship across biology, ecology, social science, and many other fields! Here is some of the published work Glacier National Park Conservancy donors have made possible.

Year Published:

2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 | 2014


2024

Paired acoustic recordings and point count surveys reveal Clark’s nutcracker and whitebark pine associations across Glacier National Park

Vladimir Kovalenko, Jeffrey W. Doser, Lisa J. Bate & Diana L. Six

Ecology and Evolution – January 24, 2024

Abstract: We investigated how stand characteristics of whitebark pine in a protected area (Glacier National Park, Montana, USA) influenced occupancy and vocal activity patterns in Clark’s nutcracker. Using Bayesian spatial occupancy models and generalized linear mixed models, we found that habitat use of Clark’s nutcracker was primarily supported by greater cone density and increasing diameter of live whitebark pine.

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Quantifying effectiveness and best practices for bumblebee identification from photographs

A. M. Colgan, R. G. Hatfield, A. Dolan, W. Velman, R. E. Newton & T. A. Graves

Scientific Reports – January 10, 2024

Abstract: Understanding pollinator networks requires species level data on pollinators. New photographic approaches to identification provide avenues to data collection that reduce impacts on declining bumblebee species, but limited research has addressed their accuracy. Using blind identification of 1418 photographed bees, of which 561 had paired specimens, we assessed identification and agreement across 20 bumblebee species netted in Montana, North Dakota, and South Dakota by people with minimal training. An expert identified 92.4% of bees from photographs, whereas 98.2% of bees were identified from specimens. Photograph identifiability decreased for bees that were wet or matted; bees without clear pictures of the abdomen, side of thorax, or top of thorax; bees photographed with a tablet, and for species with more color morphs. Across paired specimens, the identification matched for 95.1% of bees. When combined with a second opinion of specimens without matching identifications, data suggested a similar misidentification rate (2.7% for photographs and 2.5% specimens). We suggest approaches to maximize accuracy, including development of rulesets for collection of a subset of specimens based on difficulty of identification and to address cryptic variation, and focused training on identification that highlights detection of species of concern and species frequently confused in a study area.

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2023

Snow patch refugia benefits for species of periglacial zones—Evidence from a high-elevation obligate

Forest P. Hayes & Joel Berger

PNAS Nexus – November 7, 2023

Abstract: Conserving Earth’s most rapidly changing biomes necessitates understanding biological consequences of altered climes. Past species- and taxa-level responses to warming environs include numerous concentrated extirpations at the southern peripheries of distributions during the late Pleistocene. Less clear are localized capacities of cold-adapted species to mitigate thermal challenges against warming temperatures, especially through proximate behavioral and physiological adjustments. Whereas snow patches persist in periglacial zones and elsewhere, broad reductions in seasonal snow raise concerns about how and why species continue to use them. If snow patches play a functional role to combat increasing thermal demands, we predicted individuals would display an array of autonomic responses to increased temperatures modulated by wind, ambient temperature, and winter fur on and away from snow patches. We tested these predictions using a mammalian exemplar of high latitude and high elevation, mountain goats (Oreamnos americanus), using two sites in the northern Rocky Mountains, USA. Surprisingly, and contrary to expectations of reduced thermal stress, respiration rates were not decreased on snow patches but use of snow was strongly correlated with decreased metrics of insect harassment. As snow cover continues to decline in montane environs, the persistence of cold-adapted species depends on navigating concurrent changes in biotic communities and thermal environments and balancing competing pressures on behavioral and biological responses.

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Partial COVID-19 closure of a national park reveals negative influence of low-impact recreation on wildlife spatiotemporal ecology

Alissa Kate Anderson, John S. Waller & Daniel H. Thornton

Scientific Reports – January 13, 2023

Abstract: Human presence exerts complex effects on the ecology of species, which has implications for biodiversity persistence in protected areas experiencing increasing human recreation levels. However, the difficulty of separating the effect on species of human presence from other environmental or disturbance gradients remains a challenge. The cessation of human activity that occurred with COVID-19 restrictions provides a ‘natural experiment’ to better understand the influence of human presence on wildlife. Here, we use a COVID-19 closure within a heavily visited and highly protected national park (Glacier National Park, MT, USA) to examine how ‘low-impact’ recreational hiking affects the spatiotemporal ecology of a diverse mammal community. Based on data collected from camera traps when the park was closed and then subsequently open to recreation, we found consistent negative responses to human recreation across most of our assemblage of 24 species, with fewer detections, reduced site use, and decreased daytime activity. Our results suggest that the dual mandates of national parks and protected areas to conserve biodiversity and promote recreation have potential to be in conflict, even for presumably innocuous recreational activities. There is an urgent need to understand the fitness consequences of these spatiotemporal changes to inform management decisions in protected areas.

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Ecological Consequences of Warming Climes for Cold-Adapted Species–Evidence from Mountain Goats

Forest Parker Hayes

Colorado State University – 2023

Abstract: Global climate change from human activity is changing ecological communities at unprecedented rates. Coupled with recent and extraordinary loss of biodiversity, assessing the consequences for vulnerable species – and effecting proactive conservation – will be fundamental to stymieing these losses. Among the areas most strongly impacted by these changes are montane regions, which are warming at rates 2–5x the global average. Within those, cold-adapted organisms are among the most strongly impacted as they may experience thermal stress at moderate temperatures. Past species- and taxa-level responses to warming environs includes numerous concentrated extirpations at the southern peripheries of distributional ranges during the late Pleistocene. Less clear are localized capacities of cold-adapted species to mitigate thermal challenges against warming temperatures, especially through proximate behavioral and physiological adjustments. In this dissertation, I address three key tendrils of the ecological consequences of warming climes for cold-adapted species. 

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Validation of a species-specific probe-based qPCR assay for the threatened meltwater stonefly, Lednia tumana, in environmental samples

Patrick R. Hutchins, Jonathan J. Giersch, Adam J. Sepulveda & Clint C. Muhlfeld

Springer – July 3, 2023

Abstract: A probe-based quantitative real-time PCR assay was developed to detect meltwater stonefly (Lednia tumana) environmental (e)DNA in water samples. The limits of detection and quantification, respectively, were 12.1 and 58.4 gene copies for calibration standards and these values were similarly low in a relevant environmental sample matrix (8.6 and 174.2, respectively). The assay’s utility was demonstrated in situ on water samples with concomitant manual invertebrate surveys from a wide range of alpine streams across L. tumana’s native range.

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Bighorn sheep associations: understanding tradeoffs of sociality and implications for disease transmission

Marie I. Tosa​, Mark J. Biel & Tabitha A. Graves

Zoological Science – August 8, 2023

Abstract: Sociality directly influences mating success, survival rates, and disease, but ultimately likely evolved for its fitness benefits in a challenging environment. The tradeoffs between the costs and benefits of sociality can operate at multiple scales, resulting in different interpretations of animal behavior. We investigated the influence of intrinsic (e.g., relatedness, age) and extrinsic factors (e.g., land cover type, season) on direct contact (simultaneous GPS locations ≤ 25 m) rates of bighorn sheep (Ovis canadensis) at multiple scales near the Waterton-Glacier International Peace Park. During 2002–2012, male and female bighorn were equipped with GPS collars. Indirect contact (GPS locations ≤ 25 m regardless of time) networks identified two major breaks whereas direct contact networks identified an additional barrier in the population, all of which corresponded with prior disease exposure metrics. More direct contacts occurred between same-sex dyads than female-male dyads and between bighorn groups with overlapping summer home ranges. Direct contacts occurred most often during the winter-spring season when bighorn traveled at low speeds and when an adequate number of bighorn were collared in the area. Direct contact probabilities for all dyad types were inversely related to habitat quality, and differences in contact probability were driven by variables related to survival such as terrain ruggedness, distance to escape terrain, and canopy cover. We provide evidence that probabilities of association are higher when there is greater predation risk and that contact analysis provides valuable information for understanding fitness tradeoffs of sociality and disease transmission potential.

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Insights from the Environment: Unveiling Methodological Biases and the Impacts of Beaver-Mediated Environmental Variation on Amphibian-Parasite Dynamics

Leah Marie Fischer

University of Montana – December 2023

Abstract: Environmental variation plays an important role in shaping patterns of parasite and pathogen infections within ecosystems and populations. Effective management of wildlife diseases hinges on the detection of parasites and pathogens, followed by the identification of trends in infections that can be used for predicting their spread and implementing control measures. Beavers are ecosystems engineers and keystone species that serve as important sources of environmental variation. In North America, beavers are promoted for the conservations of imperiled taxa like amphibians which are facing declines driven by habitat loss, parasites, and pathogens. Beavers create diverse habitats that attract amphibians, But these habitat variations have the potential to influence the dynamics of their parasites and pathogens.

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Using Stable Isotopes to Determine Natal Origin and Feeding Habits of the Army Cutworm Moth, Euxoa auxiliaris (Lepidoptera: Noctuidae)

Clare M. Dittemore, Daniel B. Tyers, David K. Weaver, Erika A. Nunlist, Bok F. Sowell, Erik Peterson & Robert K. D. Peterson

Environmental Entomology – February 18, 2023

Abstract: The army cutworm, Euxoa auxiliaris (Grote), is a migratory noctuid that is both an agricultural pest and an important late-season food source for grizzly bears, Ursus arctos horribilis (Linnaeus, Carnivora: Ursidae), within the Greater Yellowstone Ecosystem. Beyond the confirmation of the moths’ seasonal, elevational migration in the mid-1900s, little else has been documented about their migratory patterns. To address this missing ecological component, we examined (1) migratory routes during their spring and fall migratory periods throughout their natal range, the Great Plains, and (2) natal origin at two of their summering ranges using stable hydrogen (δ2H) analyses of wings from samples collected within the areas of interest. Stable carbon (δ13C) and stable nitrogen (δ15N) analyses of wings were used to evaluate larval feeding habits of the migrants and agricultural intensity of natal origin sites, respectively. Results suggest that, rather than migrating exclusively east to west, army cutworm moths are also migrating north to south during their spring migration. Moths did not exhibit natal origin site fidelity when returning to the Great Plains. Migrants collected from the Absaroka Range had the highest probability of natal origin in Alberta, British Columbia, Saskatchewan, the most southern region of the Northwest Territories, and second highest probability of origin in Montana, Wyoming, and Idaho. Migrants collected in the Lewis Range had the highest probability of origin in the same provinces of Canada. Results suggest that migrants of the Absaroka Range fed exclusively on C3 plants as larvae and rarely fed in heavily fertilized agroecosystems.

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2022

A Summer Feast Atop the Crown of the Continent: The Interplay of Grizzly Bears and Army Cutworm Moths across Glacier National Park’s Alpine Talus Slopes

Erik Peterson

Washington State University – July 2022

Abstract: In Glacier National Park, Montana, grizzly bear foraging for army cutworm moths within alpine talus slopes remains poorly understood. To better understand the distribution of army cutworm moth aggregations and grizzly bear foraging at these congregations, we implemented systematic ground surveys to record moth presence-absence and aerial surveys to record grizzly bear foraging presence. We used the resulting data to develop 1) generalized linear models of ix army cutworm moth probability of occurrence and 2) relative suitability distribution models of grizzly bear moth foraging areas. Our results indicate environmental predictors of army cutworm moth occurrence and grizzly bear foraging overlap considerably. We found army cutworm moth occurrence is influenced by elevation, geological characteristics of talus slopes, terrain wetness, and photosynthetic activity. Further, we determined grizzly bear foraging for moths is primarily predicted by moth occurrence and slope, with terrain wetness also contributing. Grizzly beararmy cutworm moth interactions occur throughout Glacier’s alpine, particularly within the park’s highest massifs, which are centers of activity for this remarkable predator-prey association. While widespread, these areas comprise less than 0.3% of the park’s total land area. This research enhances our understanding of grizzly bear use of this nourishing food resource in Glacier and provides useful information to managers for conserving these habitats in the future, amid growing pressure from off trail recreators and changing climatic conditions.

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Glacier’s Wildlife: A Noninvasive Investigation of a Canada Lynx Population and Wildlife Spatiotemporal Response to Recreation in a Popular National Park

Alissa Kate Anderson

Washington State University – May 2022

Abstract: Glacier National Park (GNP) is a large, protected area within the northern Rockies Canada lynx (Lynx canadensis) recovery unit, however knowledge of lynx distribution within the park is limited. We completed the first park-wide occupancy survey of lynx using an array of passive camera traps during summer. Within a smaller area of the park, we also tested the possibility of identifying individuals from subtle markings on the inside of the front leg to estimate density via spatially explicit capture-recapture. Finally, we linked park-wide predictions of occupancy with local density to estimate lynx population size across GNP. We found lynx distributed across much of the park and in the density study area we were able to successfully identify ~75% of lynx captures to individual based on coat markings. We estimated the average park-wide lynx density at 1.05/100 km² resulting in an estimated population of 43.07 (SE: 13.78, v 95% CI: 23.37 – 79.41) lynx during summer. Based on our results, we propose that GNP should be considered as a potentially important area for lynx habitat refugia in a warming climate.

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Species conflict at Earth’s edges–Contests, climate, and coveted resources

Joel Berger, Mark Biel & Forest Hayes

Frontiers in Ecology and Evolution – October 17, 2022 

Abstract: Direct conflict between species is an infrequently witnessed biological phenomenon. Potential drivers of such contests can include climate change, especially at Earth’s high elevation and latitudinal extremes where temperatures warm 2–5 times faster than elsewhere and hydro-geomorphic processes such as glacial recession and soil erosion affect species access to abiotic resources. We addressed a component of this broader issue by empirical assessments of mammalian conflict over access to four abiotic resources – minerals, water, snow, and shade – by annotation of past studies and by empirical data collection. Evidence for Nearctic and Palearctic mammals indicates that when desert waters are in short supply, contests intensify, generally favoring larger species regardless of their status as native or exotic. Our empirical data indicate that contests between two large and approximately similarly-sized mammals – mountain goats (Oreamnos americanus) and bighorn sheep (Ovis canadensis) – along a 2,500 km gradient at three high-altitude (above tree-line) sites in the Rocky Mountains of North America, result in striking asymmetries; goats dominated > 95% of interactions. Despite far fewer observations of encounters to access shade or snow patches, an increasingly prominent dialog needs to be held about rarely explored biological phenomena where less is known than we might otherwise presume, whether induced by climate or increasing anthropological alteration because of underpinnings to understand community structure and conservation planning. Observations on the frequency and intensity by which individuals escalate behavior to access abiotic resources remains an underappreciated arena to help identify the proximate importance of scarcity in the natural environment. Notwithstanding Darwin’s prediction some 165 years ago that populations in extreme environments (high-latitude, high-altitude) are more likely to be impacted by abiotic variables than biotic, conflict between species may be reflective of climate degradation coupled with the changing nature of coveted resources.

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Average kinship within bighorn sheep populations is associated with connectivity, augmentation, and bottlenecks

Elizabeth Flesch, Tabitha Graves, Jennifer Thomson, Kelly Proffitt & Robert Garrott

Ecosphere – March 16, 2022

Abstract: Understanding the influence of population attributes on genetic diversity is important to advancement of biological conservation. Because bighorn sheep (Ovis canadensis) populations vary in size and management history, the species provides a unique opportunity to observe the response of average pairwise kinship, inversely related to genetic diversity, to a spectrum of natural and management influences. We estimated average pairwise kinship of bighorn sheep herds and compared estimates with population origin (native/indigenous/extant or reintroduced), historical minimum count, connectivity, and augmentation history, to determine which predictors were the most important. We evaluated 488 bighorn sheep from 19 wild populations with past minimum counts of 16–562 animals, including native and reintroduced populations that received 0–165 animals in augmentations. Using the Illumina High Density Ovine array, we generated a dataset of 7728 single nucleotide polymorphisms and calculated average pairwise kinship for each population. Multiple linear regression analysis determined that connectivity between populations via dispersal, greater number of animals received in augmentations, and greater minimum count were correlated with lower average pairwise kinship at the population level, and whether the population was extant or reintroduced was less important. Thus, our results indicated that genetic isolation of populations can result in increased levels of inbreeding. By determining that natural and human-assisted gene flow were likely the most important influences of average pairwise kinship at the population level, this study can serve as a benchmark for future management of bighorn sheep populations and aid in identifying populations of genetic concern to define priorities for conservation of wild populations.

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2021

The smell of success: reproductive success related to rub behavior in brown bears

Andrea T. Morehouse, Anne E. Loosen, Tabitha A. Graves & Mark S. Boyce

PLOS ONE – March 3, 2021

Abstract: Several species of bears are known to rub deliberately against trees and other objects, but little is known about why bears rub. Patterns in rubbing behavior of male and female brown bears (Ursus arctos) suggest that scent marking via rubbing functions to communicate among potential mates or competitors. Using DNA from bear hairs collected from rub objects in southwestern Alberta from 2011–2014 and existing DNA datasets from Montana and southeastern British Columbia, we determined sex and individual identity of each bear detected. Using these data, we completed a parentage analysis. From the parentage analysis and detection data, we determined the number of offspring, mates, unique rub objects where an individual was detected, and sampling occasions during which an individual was detected for each brown bear identified through our sampling methods. Using a Poisson regression, we found a positive relationship between bear rubbing behavior and reproductive success; both male and female bears with a greater number of mates and a greater number of offspring were detected at more rub objects and during more occasions. Our results suggest a fitness component to bear rubbing, indicate that rubbing is adaptive, and provide insight into a poorly understood behaviour.

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Migratory connectivity and nesting behavior in harlequin ducks (Histrionicus histrionicus) based on light-level geolocator data

Beth MacCallum, Alice Paquet, Lisa Bate, Chris Hammond, Kristina Smucker, et al.

Waterbirds – September 1, 2021

Abstract: The Harlequin Duck (Histrionicus histrionicus) is a species of conservation priority in western North America. Harlequin Ducks breed in small, isolated populations and have specific nesting requirements. Archival, light-level geolocators are increasingly being used as a low-cost, non-invasive tracking technology to explore migratory connectivity. From 2015-2019, geolocators were deployed on 70 Harlequin Ducks in breeding streams of the Rocky Mountains, Canada and USA, to obtain information on connectivity (breeding to non-breeding), moltwinter sites, dispersal, and breeding phenology. Twenty-two of the 70 geolocators were retrieved from locations in the Rocky Mountains (Alberta, Canada; Montana and Wyoming, USA) and analyzed using the TwGeos and FLightR R packages. Harlequin Ducks from the warmer climate of northwest Montana migrated in spring and started incubation one to two weeks earlier than ducks in west-central Alberta and the greater Yellowstone area. During the non-breeding period, individuals dispersed along the Pacific coast, from Oregon to the Alaskan Panhandle, independent of breeding site. Females that incubated successfully spent 32-34 days incubating, which is several days longer than what is in the literature. Use of geolocators provided detailed information about migration connectivity and breeding behavior in a cost effective and relatively non-invasive manner.

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2020

Connectivity in the Crown: US Highway 2 Wildlife Crossings

John Waller, Tabitha Graves, Brad Anderson, Brandon Kittson & Sarah Gaulke

National Park Service – 202

Abstract: This effort resulted in 621 wildlife observations of 26 species collected from hundreds of interactions with employees and the public, 31 businesses visited, and 11 events held or attended. We mapped 230 previously unrecorded wildlife trails between West Glacier and Columbia Falls and measured and photographed 390 culverts between East Glacier and Columbia Falls. We installed 12 trail cameras that captured 9248 wildlife images comprised of 12 species. This information is presented here and compared with previous studies of the corridor to recommend potential highway crossing locations for more intensive study.

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Evaluating wildlife translocations using genomics: a bighorn sheep case study

Elizabeth P. Flesch, Tabitha A. Graves, Jennifer M. Thomson, Kelly M. Proffitt, P. J. White, Thomas R. Stephenson & Robert A. Garrott

Ecology and Evolution – November 21, 2020

Abstract: Wildlife restoration often involves translocation efforts to reintroduce species and supplement small, fragmented populations. We examined the genomic consequences of bighorn sheep (Ovis canadensis) translocations and population isolation to enhance understanding of evolutionary processes that affect population genetics and inform future restoration strategies. We conducted a population genomic analysis of 511 bighorn sheep from 17 areas, including native and reintroduced populations that received 0–10 translocations. Using the Illumina High Density Ovine array, we generated datasets of 6,155 to 33,289 single nucleotide polymorphisms and completed clustering, population tree, and kinship analyses. Our analyses determined that natural gene flow did not occur between most populations, including two pairs of native herds that had past connectivity. We synthesized genomic evidence across analyses to evaluate 24 different translocation events and detected eight successful reintroductions (i.e., lack of signal for recolonization from nearby populations) and five successful augmentations (i.e., reproductive success of translocated individuals) based on genetic similarity with the source populations. A single native population founded six of the reintroduced herds, suggesting that environmental conditions did not need to match for populations to persist following reintroduction. Augmentations consisting of 18–57 animals including males and females succeeded, whereas augmentations of two males did not result in a detectable genetic signature. Our results provide insight on genomic distinctiveness of native and reintroduced herds, information on the relative success of reintroduction and augmentation efforts and their associated attributes, and guidance to enhance genetic contribution of augmentations and reintroductions to aid in bighorn sheep restoration.

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Population Structure, Gene Flow, and Genetic Diversity of Rocky Mountain Bighorn Sheep Informed by Genomic Analysis

Elizabeth Pearl Flesch

Montana State University – July 2020

Abstract: This dissertation evaluated the genomics of bighorn sheep (Ovis canadensis) herds across the Rocky Mountain West to determine optimal sample size for estimating kinship within and between populations (Chapter Two), to detect gene flow due to natural dispersal and translocations (Chapter Three), and to evaluate the correlation between genetic diversity and influences on population size (Chapter Four). To date, wildlife managers have moved many bighorn sheep across the Rocky Mountain West in an effort to provide new genetic diversity to isolated herds. However, little is known about the genetics of these herds and the real impacts of translocations. To learn how populations have been impacted by these management actions, we genotyped 511 bighorn sheep from multiple populations using a new cutting-edge genomic research technique, the Illumina Ovine High Density array, which contained about 24,000 to 30,000 single nucleotide polymorphisms informative for Rocky Mountain bighorn sheep. First, we determined that a sample size of 20 to 25 bighorn sheep was adequate for assessment of intra- and interpopulation kinship. In addition, we concluded that a universal sample size rule for all wild populations or genetic marker types may not be able to sufficiently address the complexities that impact genomic kinship estimates. Secondly, we synthesized genomic evidence across multiple analyses to evaluate 24 different translocation events; we detected eight successful reintroductions and five successful augmentations. One native population founded most of the examined reintroduced herds, suggesting that environmental conditions did not need to match for populations to persist following reintroduction. Finally, we determined that influences on population size over time were correlated with genetic diversity. Gene flow variables, including unassisted connectivity and animals contributed in augmentations, were more important predictors than historic minimum population size and origin (i.e. native vs. reintroduced). This hypothesis-based research approach will give wildlife managers additional biological insight to help inform various management options for bighorn sheep restoration and conservation.

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Specialized meltwater biodiversity persists despite widespread deglaciation

Clint C. Muhlfeld, Timothy J. Cline, J. Joseph Giersch, Erich Peitzsch, Caitlyn Florentine, Dean Jacobsen & Scott Hotaling

PNAS – May 18, 2020

Abstract: Glaciers are important drivers of environmental heterogeneity and biological diversity across mountain landscapes. Worldwide, glaciers are receding rapidly due to climate change, with important consequences for biodiversity in mountain ecosystems. However, the effects of glacier loss on biodiversity have never been quantified across a mountainous region, primarily due to a lack of adequate data at large spatial and temporal scales. Here, we combine high-resolution biological and glacier change (ca. 1850–2015) datasets for Glacier National Park, USA, to test the prediction that glacier retreat reduces biodiversity in mountain ecosystems through the loss of uniquely adapted meltwater stream species. We identified a specialized cold-water invertebrate community restricted to the highest elevation streams primarily below glaciers, but also snowfields and groundwater springs. We show that this community and endemic species have unexpectedly persisted in cold, high-elevation sites, even in catchments that have not been glaciated in ∼170 y. Future projections suggest substantial declines in suitable habitat, but not necessarily loss of this community with the complete disappearance of glaciers. Our findings demonstrate that high-elevation streams fed by snow and other cold-water sources continue to serve as critical climate refugia for mountain biodiversity even after glaciers disappear.

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2019

Using bear rub data and spatial capture-recapture models to estimate trend in a brown bear population

Katherine C. Kendall, Tabitha A. Graves, J. Andrew Royle, Amy C. Macleod, Kevin S. McKelvey, John Boulanger & John S. Waller

Scientific Reports – November 14, 2019

Abstract: Trends in population abundance can be challenging to quantify during range expansion and contraction, when there is spatial variation in trend, or the conservation area is large. We used genetic detection data from natural bear rubbing sites and spatial capture-recapture (SCR) modeling to estimate local density and population growth rates in a grizzly bear population in northwestern Montana, USA. We visited bear rubs to collect hair in 2004, 2009—2012 (3,579—4,802 rubs) and detected 249—355 individual bears each year. We estimated the finite annual population rate of change 2004—2012 was 1.043 (95% CI = 1.017—1.069). Population density shifted from being concentrated in the north in 2004 to a more even distribution across the ecosystem by 2012. Our genetic detection sampling approach coupled with SCR modeling allowed us to estimate spatially variable growth rates of an expanding grizzly bear population and provided insight into how those patterns developed. The ability of SCR to utilize unstructured data and produce spatially explicit maps that indicate where population change is occurring promises to facilitate the monitoring of difficult-to-study species across large spatial areas.

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Drought and moisture availability and recent Western spruce budworm outbreaks in the Western United States

Bingbing Xu, Jeffrey A. Hicke & John T. Abatzoglou

Forests – April 24, 2019

Abstract: Western spruce budworm (WSBW) is a common defoliating insect that has caused extensive damage and mortality to a number of tree species across the western United States (US). Past studies have linked outbreaks of WSBW to increased moisture stress of host trees in the Northwest and decreased moisture stress in the Southwest. Our study analyzed seasonal drought stress metrics with WSBW outbreaks within Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) forests in the western US during 1997–2015. Superposed epoch analysis and defoliation area growth rates (representing insect population growth rates) were assessed to quantify the drought conditions associated with the initiation and continuation of outbreaks, respectively. We found that multiple years of drought occurred prior to and during outbreak initiation in the Northwest, and that outbreak initiation in the Southwest was associated with only weak drought or neutral conditions. During the outbreak continuation stage, there was a weak positive correlation between May moisture availability and defoliation area growth rates in the Southwest (R2 = 0.12), but no clear relationship was identified in the Northwest. Increased frequency of summer droughts such as these expected from climate change may increase WSBW outbreaks and promote tree dieoff. Improved understanding of the role of different influences of drought and moisture availability across landscapes will lead to improved predictions and management of future outbreaks of WSBW.

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2018

Congruent population genetic structure but differing depths of divergence for three alpine stoneflies with similar ecology and geographic distributions

Scott Hotaling, J. Joseph Giersch, Debra S. Finn, Lusha M. Tronstad, Steve Jordan, Larry E. Serpa, Ronald G. Call, Clint C. Muhlfeld & David W. Weisrock

Freshwater Biology – December 17, 2018

Abstract: Comparative population genetic studies provide a powerful means for assessing the degree to which evolutionary histories may be congruent among taxa while also highlighting the potential for cryptic diversity within existing species. In the Rocky Mountains, three confamilial stoneflies (Zapada glacier, Lednia tumana, and Lednia tetonica; Plecoptera, Nemouridae) occupy cold alpine streams that are primarily fed by melting ice. Lednia tumana and L. tetonica are sister species diagnosed from systematic morphological differences, and they are endemic to areas surrounding Glacier National Park and Grand Teton National Park, respectively, in the U.S. Rocky Mountains. Zapada glacier is also present in alpine streams from Glacier National Park to the Teton Range, sometimes co-occurring with either Lednia species. We used mitochondrial sequence data to clarify species boundaries, compare population genetic patterns, and test demographic models in a coalescent framework for the three stoneflies. We addressed four questions: (1) Is there genetic support for the morphology-based species boundaries in Lednia? (2) Is there genetic support for cryptic, or as-yet undescribed, diversity within Z. glacier? (3) Do similar geographic distributions and ecological requirements yield spatial congruence of genetic structure between high-elevation Lednia and Z. glacier populations? (4) Is there evidence for contemporary gene flow among isolated populations in either group? Our results supported the existing taxonomy with Z. glacier and the two Lednia species differing in their depths of divergence among study regions (e.g. maximum sequence divergence within Z. glacier = 1.2% versus 5% between L. tumana and L. tetonica). However, spatial population genetic patterns were broadly congruent, indicating stonefly populations isolated on mountaintop islands. Coalescent modelling supported the possibility of rare, extremely limited contemporary gene flow among Z. glacier populations, with no support for gene flow between L. tumana and L. tetonica. The focal stoneflies and associated assemblages occupy the highest elevation, coldest permanent alpine streams in the study region. This lotic habitat type faces an uncertain future under a diminishing alpine cryosphere. Given spatial congruence of genetic structure demonstrating unique biodiversity associated with individual alpine islands, we encourage conservation management strategies be developed and applied at corresponding spatial scales.

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Glacial loss and its effect on riparian vegetation of alpine streams

Cristina McKernan, David J. Cooper & E. William Schweiger

Freshwater Biology – February 22, 2018

Abstract: Rising global temperature is expected to increase alpine glacier mass loss with cascading effects on alpine habitats and biota. Currently, there is limited information on the effects of climate change on alpine riparian vegetation including quantitative assessments of geophysical habitat context. We measured geomorphic conditions and riparian vegetation composition of alpine streams across a chronosequence of sites supported hydrologically by glaciers, permanent snowfields (PS) and seasonal snowfields (SS) in Glacier National Park (GNP), Montana, USA. Responses in the system to possible climate-driven shifts in hydrologic regime were identified using multivariate analyses. Glacier-fed streams had higher discharge and stream power and lower substrate stability than streams fed by PS and SS. Streams fed by PS supported a higher number of species than other stream types. Glacier-fed streams were characterised by higher abundance of disturbance-adapted shrub species than PS and SS. By applying projections from climate models that forecast total glacial loss in GNP by 2030 to our data, we predict that stream geophysical conditions will shift, resulting in a loss of physical habitat for shrub species, an increase in habitat for herbaceous species, and ultimately a homogenisation of riparian communities in the alpine zone. Our study identifies glaciers as drivers of alpine riverine ecosystems and highlights the importance of examining geophysical habitat linked to hydrologic regimes and glaciers to better understand the impacts to biota under future climate scenarios. We provide a framework for relating fluvial biological and hydrogeomorphic processes in the context of alpine glacial recession.

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Remote Sensing of Avalanche Paths in Glacier National Park, Montana

Morgan Voss

University of Montana – December 2018

Abstract: Snow avalanches are the common form of mass wasting in the high mountain environments of Glacier National Park (GNP), Montana. These natural disturbances play important roles in mountain ecosystems by regularly disturbing montane systems, providing critical habitat for some species, transporting debris, and influencing vegetation and fire dynamics. Since the 1900s, natural avalanche-related activity recorded along important transportation corridors within the park has frequently disrupted transportation.

While many of the steep slopes of GNP are susceptible to avalanching, formal inventories exist only for small, critical portions of the park and they vary substantially from one another. GNP’s protected status does not allow for avalanche mitigation, allowing this area to serve as a natural mountain environment for studying these processes. A current, high-resolution inventory of avalanche locations in the park is needed for the entirety of the Park.

Imagery and digital elevation models (DEMs) were used to map the distinct biogeographic and topographic patterns left by avalanching using machine learning methods. Mosaics of National Agricultural Imagery Program (NAIP) aerial photographs acquired in 2013 were segmented to map avalanche tracks. Principal components from the imagery and derivatives of the DEM were used as input to a Random Forests algorithm which mapped the most likely class for each segment using a probabilistic approach. Avalanche paths were found to comprise approximately 5-12% of the park, along predominantly south and southeasterly facing slopes between 20° to 40°. While this estimate is similar to previous studies, this work did not map starting or runout zones which would have increased the total area. The paths predicted provide a comprehensive inventory that can be used to monitor shifts in vegetation and climate dynamics within the disturbance regime. Changes were clearly seen in the contraction and expansion of trim lines of some avalanche paths in recent imagery. Future research could use this work as a baseline for time-series analysis.

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The role of disease, habitat, individual condition, and herd attributes on bighorn sheep recruitment and population dynamics in Montana

Robert Garrott, Jay Rotella, Elizabeth Flesch, Carson Butler, Emily Almberg, Kelly Proffitt, Ethan Lula, Blake Lowrey & Terrill Patterson

Wildlife Restoration – 2018

Abstract: In 2013, MFWP and MSU initiated a collaborative six-year research program designed to assess factors driving bighorn sheep population dynamics across Montana. The integrated study design entails using standardized methods to investigate demographic rates, body condition and nutrition, respiratory pathogens, movements, habitat use, and herd attributes across a diverse set of populations occupying a diverse set of landscapes (Figure 1). Similar designs have proven efficient at producing reliable and generalizable findings useful for management agencies. In recognition of the improved inference associated with incorporation of additional study populations, this research program has strived to incorporate data from a companion MSU bighorn sheep study (Greater Yellowstone Area Mountain Ungulate Project), has worked with the MFWP wildlife health lab to incorporate data from additional populations captured for health monitoring purposes, and has collaborated with Wyoming Game & Fish Department (WGF) to develop sampling methods that are comparable across states. This study has and will continue to greatly benefit from inclusion of these parties in the research project. This annual report is the fourth produced by this research project. All findings reported herein should be considered preliminary, as data collection and analysis are ongoing.

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2017

Comparing citizen science and professional data to evaluate extrapolated mountain goat distribution models

Elizabeth P. Flesch & Jami J. Belt

Ecosphere – February 14, 2017

Abstract: Citizen science provides a prime opportunity for wildlife managers to obtain low-cost data recorded by volunteers to evaluate species distribution models and address research objectives. Using mountain goat (Oreamnos americanus) location data collected through aerial surveys by professionals, ground surveys by professionals, and ground surveys by volunteers, we evaluated two mountain goat distribution models extrapolated across Waterton-Glacier International Peace Park. In addition, we compared mountain goat location data by observer and survey type to determine whether there were differences that affected extrapolated model evaluation. We found that all dataset types compared similarly to both mountain goat models. A mountain goat occupancy model developed in the Greater Yellowstone Area (GYA) was the most informative in describing mountain goat locations. We compared Spearman-rank correlations (rs) for occupancy probability bin ranks in the GYA model extrapolation and area-adjusted frequencies of mountain goat locations, and we found that all datasets had a positive correlation, indicating the model had useful predictive ability. Aerial observations had a slightly greater Spearman-rank correlation (rs = 0.964), followed by the professional ground surveys (rs = 0.946), and volunteer ground datasets (rs = 0.898). These results suggest that with effective protocol development and volunteer training, biologists can use mountain goat location data collected by volunteers to evaluate extrapolated models. We recommend that future efforts should apply this approach to other wildlife species and explore development of wildlife distribution models using citizen science.

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Demographic modelling reveals a history of divergence with gene flow for a glacially tied stonefly in a changing post‐Pleistocene landscape

Scott Hotaling, Clint C. Muhlfeld, J. Joseph Giersch, Omar A. Ali, Steve Jordan, Michael R. Miller, Gordon Luikart & David W. Weisrock

Journal of Biogeography – November 13, 2017

Abstract: Climate warming is causing extensive loss of glaciers in mountainous regions, yet our understanding of how glacial recession influences evolutionary processes and genetic diversity is limited. Linking genetic structure with the influences shaping it can improve understanding of how species respond to environmental change. Here, we used genome-scale data and demographic modelling to resolve the evolutionary history of Lednia tumana, a rare, aquatic insect endemic to alpine streams. We also employed a range of widely used data filtering approaches to quantify how they influenced population structure results.

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2016

Demographic mechanisms underpinning genetic assimilation of remnant groups of a large carnivore

Nathaniel Mikle, Tabitha A. Graves, Ryan P. Kovach, Katherine C. Kendall & Amy C. Macleod

Proceedings of the Royal Society B – September 28, 2016

Abstract: Current range expansions of large terrestrial carnivores are occurring following human-induced range contraction. Contractions are often incomplete, leaving small remnant groups in refugia throughout the former range. Little is known about the underlying ecological and evolutionary processes that influence how remnant groups are affected during range expansion. We used data from a spatially explicit, long-term genetic sampling effort of grizzly bears (Ursus arctos) in the Northern Continental Divide Ecosystem (NCDE), USA, to identify the demographic processes underlying spatial and temporal patterns of genetic diversity. We conducted parentage analysis to evaluate how reproductive success and dispersal contribute to spatio-temporal patterns of genetic diversity in remnant groups of grizzly bears existing in the southwestern (SW), southeastern (SE) and east-central (EC) regions of the NCDE. A few reproductively dominant individuals and local inbreeding caused low genetic diversity in peripheral regions that may have persisted for multiple generations before eroding rapidly (approx. one generation) during population expansion. Our results highlight that individual-level genetic and reproductive dynamics play critical roles during genetic assimilation, and show that spatial patterns of genetic diversity on the leading edge of an expansion may result from historical demographic patterns that are highly ephemeral.

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Comparing Bicyclists, Non-Bicyclists, and Bus Drivers in Glacier National Park

Norma Nickerson, Brian Battaglia & Kara Grau

University of Montana – March 18, 2016

Abstract: This report provides a comparison of four Glacier National Park (GNP) user groups on their opinions, attitudes and knowledge of bicycling in Glacier National Park. The four user groups were summer bicyclists, summer non-bicyclists, spring bicyclists, and bus drivers in the park. Results showed significant differences in the four groups on knowledge (bus drivers most knowledgeable), on opinions of bicycling the Going-to-the-Sun Road (summer bicyclists most positive), and future use of the road (summer and spring bicyclists most likely to agree to motorist restrictions on the road).

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Predictors of Current and Longer-Term Patterns of Abundance of American Pikas (Ochotona princeps) across a Leading-Edge Protected Area

Lucas Moyer-Horner, Erik A. Beever, Douglas H. Johnson, Mark Biel & Jami Belt

PLOS ONE – November 30, 2016

Abstract: American pikas (Ochotona princeps) have been heralded as indicators of montane-mammal response to contemporary climate change. Pikas no longer occupy the driest and lowest-elevation sites in numerous parts of their geographic range. Conversely, pikas have exhibited higher rates of occupancy and persistence in Rocky Mountain and Sierra Nevada montane ‘mainlands’. Research and monitoring efforts on pikas across the western USA have collectively shown the nuance and complexity with which climate will often act on species in diverse topographic and climatic contexts. However, to date no studies have investigated habitat, distribution, and abundance of pikas across hundreds of sites within a remote wilderness area. Additionally, relatively little is known about whether climate acts most strongly on pikas through direct or indirect (e.g., vegetation-mediated) mechanisms. During 2007–2009, we collectively hiked >16,000 km throughout the 410,077-ha Glacier National Park, Montana, USA, in an effort to identify topographic, microrefugial, and vegetative characteristics predictive of pika abundance. We identified 411 apparently pika-suitable habitat patches with binoculars (in situ), and surveyed 314 of them for pika signs. Ranking of alternative logistic-regression models based on AICc scores revealed that short-term pika abundances were positively associated with intermediate elevations, greater cover of mosses, and taller forbs, and decreased each year, for a total decline of 68% during the three-year study; whereas longer-term abundances were associated only with static variables (longitude, elevation, gradient) and were lower on north-facing slopes. Earlier Julian date and time of day of the survey (i.e., midday vs. not) were associated with lower observed pika abundance. We recommend that wildlife monitoring account for this seasonal and diel variation when surveying pikas. Broad-scale information on status and abundance determinants of montane mammals, especially for remote protected areas, is crucial for land and wildlife-resource managers trying to anticipate mammalian responses to climate change.

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Climate‐induced glacier and snow loss imperils alpine stream insects

J. Joseph Giersch, Scott Hotaling, Ryan P. Kovach, Leslie A. Jones & Clint C. Muhlfeld

Global Change Biology – November 14, 2016

Abstract: Climate warming is causing rapid loss of glaciers and snowpack in mountainous regions worldwide. These changes are predicted to negatively impact the habitats of many range-restricted species, particularly endemic, mountaintop species dependent on the unique thermal and hydrologic conditions found only in glacier-fed and snow melt-driven alpine streams. Although progress has been made, existing understanding of the status, distribution, and ecology of alpine aquatic species, particularly in North America, is lacking, thereby hindering conservation and management programs. Two aquatic insects – the meltwater stonefly (Lednia tumana) and the glacier stonefly (Zapada glacier) – were recently proposed for listing under the U.S. Endangered Species Act due to climate-change-induced habitat loss. Using a large dataset (272 streams, 482 total sites) with high-resolution climate and habitat information, we describe the distribution, status, and key environmental features that limit L. tumana and Z. glacier across the northern Rocky Mountains. Lednia tumana was detected in 113 streams (175 sites) within Glacier National Park (GNP) and surrounding areas. The probability of L. tumana occurrence increased with cold stream temperatures and close proximity to glaciers and permanent snowfields. Similarly, densities of L. tumana declined with increasing distance from stream source. Zapada glacier was only detected in 10 streams (24 sites), six in GNP and four in mountain ranges up to ~600 km southwest. Our results show that both L. tumana and Z. glacier inhabit an extremely narrow distribution, restricted to short sections of cold, alpine streams often below glaciers predicted to disappear over the next two decades. Climate warming-induced glacier and snow loss clearly imperils the persistence of L. tumana and Z. glacier throughout their ranges, highlighting the role of mountaintop aquatic invertebrates as sentinels of climate change in mid-latitude regions.

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Nature vs. nurture: evidence for social learning of conflict behavior in grizzly bears

Andrea T. Morehouse, Tabitha A. Graves, Nate Mikle & Mark S. Boyce

PLOS ONE – November 16, 2016

Abstract: The propensity for a grizzly bear to develop conflict behaviours might be a result of social learning between mothers and cubs, genetic inheritance, or both learning and inheritance. Using non-invasive genetic sampling, we collected grizzly bear hair samples during 2011–2014 across southwestern Alberta, Canada. We targeted private agricultural lands for hair samples at grizzly bear incident sites, defining an incident as an occurrence in which the grizzly bear caused property damage, obtained anthropogenic food, or killed or attempted to kill livestock or pets. We genotyped 213 unique grizzly bears (118 M, 95 F) at 24 microsatellite loci, plus the amelogenin marker for sex. We used the program COLONY to assign parentage. We evaluated 76 mother-offspring relationships and 119 father-offspring relationships. We compared the frequency of problem and non-problem offspring from problem and non-problem parents, excluding dependent offspring from our analysis. Our results support the social learning hypothesis, but not the genetic inheritance hypothesis. Offspring of problem mothers are more likely to be involved in conflict behaviours, while offspring from non-problem mothers are not likely to be involved in incidents or human-bear conflicts themselves (Barnard’s test, p = 0.05, 62.5% of offspring from problem mothers were problem bears). There was no evidence that offspring are more likely to be involved in conflict behaviour if their fathers had been problem bears (Barnard’s test, p = 0.92, 29.6% of offspring from problem fathers were problem bears). For the mother-offspring relationships evaluated, 30.3% of offspring were identified as problem bears independent of their mother’s conflict status. Similarly, 28.6% of offspring were identified as problem bears independent of their father’s conflict status. Proactive mitigation to prevent female bears from becoming problem individuals likely will help prevent the perpetuation of conflicts through social learning.

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Feather and faecal corticosterone concentrations predict future reproductive decisions in harlequin ducks (Histrionicus histrionicus)

Warren K. Hansen, Lisa J. Bate, Devin W. Landry, Olivier Chastel, Charline Parenteau & Creagh W. Breuner

Conservation Physiology – June 6, 2016

Abstract: Understanding sources of reproductive variation can inform management and conservation decisions, population ecology and life-history theory. Annual reproductive variation can drive population growth rate and can be influenced by factors from across the annual cycle (known as carry-over effects). The majority of studies, however, focus solely on the role of current environmental events. Past events often influence future reproductive decisions and success but can be logistically difficult to collect and quantify, especially in migratory species. Recent work indicates that glucocorticoids may prove good indicators to evaluate carry-over effects across life-history transitions. Here, we evaluated three different measures of glucocorticoid physiology (feathers, faeces and plasma) to evaluate the predictability of future breeding decision in the harlequin duck (Histrionicus histrionicus). We collected tail and back feathers, plasma and faeces for glucocorticoid analysis, and fitted female harlequin ducks with very high-frequency transmitters to track their breeding decisions. Both back feathers (moulted immediately before the current season) and faecal glucocorticoid metabolites were identified as important predictive factors of reproductive decisions; high concentrations of glucocorticoid metabolites in back feathers and faeces predicted a higher likelihood of reproductive deferral for the year. Although back and tail feather corticosterone concentrations were correlated, tail feathers (moulted at the end of the previous breeding season) did not predict breeding decisions. Plasma corticosterone concentrations were collected over too broad a time range after capture to be useful in this study. This study demonstrates the utility of non-invasive corticosterone metrics in predicting breeding decisions and supports the use of feathers to measure carry-over effects in migratory birds. With this technique, we identified the prenuptial moult as an important life-history phase that contributes to reproductive decisions. Identification of critical life-history phases is paramount to efficient management of species.

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Assessing Going-to-the-Sun Road Travelers’ Attitudes, Knowledge, and Perceptions of Bicycling

Brian Battaglia & Norma P. Nickerson

University of Montana: Institute for Tourism and Recreation Research Publications – May 11, 2016

Abstract: Visitors of the Going-to-the-Sun Road (GTSR) are primarily scenic drivers, yet niche groups of bicyclists have a stake in sharing the GTSR. Conducting a quantitative survey assessment on the bicycling attitudes of visitors produced key findings for determining visitor support for bicycling along the GTSR. Park officials are in a position to evaluate data on bicycling attitudes for visitor management and transportation decision making along the Going-to-the-Sun Road.

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Methodological considerations for measuring glucocorticoid metabolites in feathers

Sara A. Berk, Julie R. McGettrick, Warren K. Hansen & Creagh W. Breuner

Conservation Physiology – June 10, 2016

Abstract: In recent years, researchers have begun to use corticosteroid metabolites in feathers (fCORT) as a metric of stress physiology in birds. However, there remain substantial questions about how to measure fCORT most accurately. Notably, small samples contain artificially high amounts of fCORT per millimetre of feather (the small sample artefact). Furthermore, it appears that fCORT is correlated with circulating plasma corticosterone only when levels are artificially elevated by the use of corticosterone implants. Here, we used several approaches to address current methodological issues with the measurement of fCORT. First, we verified that the small sample artefact exists across species and feather types. Second, we attempted to correct for this effect by increasing the amount of methanol relative to the amount of feather during extraction. We consistently detected more fCORT per millimetre or per milligram of feather in small samples than in large samples even when we adjusted methanol:feather concentrations. We also used high-performance liquid chromatography to identify hormone metabolites present in feathers and measured the reactivity of these metabolites against the most commonly used antibody for measuring fCORT. We verified that our antibody is mainly identifying corticosterone (CORT) in feathers, but other metabolites have significant cross-reactivity. Lastly, we measured faecal glucocorticoid metabolites in house sparrows and correlated these measurements with corticosteroid metabolites deposited in concurrently grown feathers; we found no correlation between faecal glucocorticoid metabolites and fCORT. We suggest that researchers should be cautious in their interpretation of fCORT in wild birds and should seek alternative validation methods to examine species-specific relationships between environmental challenges and fCORT.

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Mercury hazard assessment for piscivorous wildlife in Glacier National Park

Craig P. Stafford, Christopher C. Downs & Heiko W. Langner

Northwest Science – September 1, 2016

Abstract: We examined the mercury hazard posed to selected piscivorous wildlife in Glacier National Park (GNP), Montana. Logging Lake was our focal site where we estimated the dietary mercury concentrations of wildlife (common loon [Gavia immer], American mink [Neovison vison], river otter [Lontra canadensis], and belted kingfisher [Megaceryle alcyon]) by assuming that fishes were consumed in proportion to their relative abundances. To evaluate if Logging Lake provided a suitable baseline for our study, we made geographic comparisons of fish mercury levels and investigated the distribution and abundance of high mercury fishes within GNP. We complimented our assessment by examining selenium:mercury molar ratios in fishes from Logging Lake and Saint Mary Lake. Our results suggest fish consumption does not imperil wildlife from Logging Lake based on published thresholds for adverse mercury effects, but some hazard may exist particularly if there is strong feeding selectivity for the most contaminated species, northern pikeminnow (Ptychocheilus oregonensis). The geographic comparisons of fish mercury levels, together with the distribution and abundance of high mercury fishes within GNP, suggest that Logging Lake provided a relatively protective baseline among our study lakes. Risk may be further reduced by the molar excess of selenium relative to mercury, particularly in the smaller fishes typically consumed by GNP wildlife. Our findings contrast with studies from northeastern US and southeastern Canada where greater mercury hazard to wildlife exists. An emergent finding from our research is that waterborne concentrations of methylmercury may provide limited insight into regional differences in fish mercury levels.

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2015

Modeling behavioral thermoregulation in a climate change sentinel

Lucas Moyer-Horner, Paul D. Mathewson, Gavin M. Jones, Michael R. Kearney & Warren P. Porter

Ecology and Evolution – November 24, 2015

Abstract: When possible, many species will shift in elevation or latitude in response to rising temperatures. However, before such shifts occur, individuals will first tolerate environmental change and then modify their behavior to maintain heat balance. Behavioral thermoregulation allows animals a range of climatic tolerances and makes predicting geographic responses under future warming scenarios challenging. Because behavioral modification may reduce an individual’s fecundity by, for example, limiting foraging time and thus caloric intake, we must consider the range of behavioral options available for thermoregulation to accurately predict climate change impacts on individual species. To date, few studies have identified mechanistic links between an organism’s daily activities and the need to thermoregulate. We used a biophysical model, Niche Mapper, to mechanistically model microclimate conditions and thermoregulatory behavior for a temperature-sensitive mammal, the American pika (Ochotona princeps). Niche Mapper accurately simulated microclimate conditions, as well as empirical metabolic chamber data for a range of fur properties, animal sizes, and environmental parameters. Niche Mapper predicted pikas would be behaviorally constrained because of the need to thermoregulate during the hottest times of the day. We also showed that pikas at low elevations could receive energetic benefits by being smaller in size and maintaining summer pelage during longer stretches of the active season under a future warming scenario. We observed pika behavior for 288 h in Glacier National Park, Montana, and thermally characterized their rocky, montane environment. We found that pikas were most active when temperatures were cooler, and at sites characterized by high elevations and north-facing slopes. Pikas became significantly less active across a suite of behaviors in the field when temperatures surpassed 20°C, which supported a metabolic threshold predicted by Niche Mapper. In general, mechanistic predictions and empirical observations were congruent. This research is unique in providing both an empirical and mechanistic description of the effects of temperature on a mammalian sentinel of climate change, the American pika. Our results suggest that previously underinvestigated characteristics, specifically fur properties and body size, may play critical roles in pika populations’ response to climate change. We also demonstrate the potential importance of considering behavioral thermoregulation and microclimate variability when predicting animal responses to climate change.

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2014

Causes of annual reproductive variation and anthropogenic disturbance in harlequin ducks breeding in glacier national park, montana

Warren Kevin Hansen

University of Montana – May 2014

Abstract: Annual reproductive variation is the central focus of many ecological studies. Variation in reproductive success is an important vital rate to study because it can lead to inferences about population health, extinction risk, human disturbance and habitat quality. The identification of the causes of reproductive variability can help guide conservation and management efforts of a species. In Glacier National Park, Montana I studied causes of annual reproductive variation and behavioral responses to human disturbance in a breeding population of harlequin ducks (Histrionicus histrionicus). Harlequins are rare sea ducks with a Holarctic distribution and winter along rocky coast lines of North America. Females reach reproductive maturity at age 3. At this time they bond with a male that they will breed with for life. Recent band re-sighting has revealed that these ducks can live up to at least 21 years. In spring pairs migrate inland to the female’s natal montane stream to breed. My study focused on the breeding season from April – September on Upper McDonald Creek, Glacier National Park, Montana. My objective was to study 3 potential indirect and direct sources of reproductive variation in Harlequin ducks on this breeding stream; 1) stream flow effects on annual reproductive success, 2) human presence and effects on stream patch occupancy and resource selection, and 3) carry-over effects of physiological measures of body condition, baseline corticosterone levels (primary stress hormone in birds), and integrated measures of corticosterone deposition in feathers. For my first objective I identified 4 different parameters of stream flow that accounted for 32% of the annual variation in reproductive success. I conclude that these parameters will be very sensitive to climate change, making reproduction challenging for harlequins into the future. For my second objective I found greater probability of occupancy of ducks in high human use sites and in stream patches closer to roads. I also found greater occupancy in pool habitat; surprisingly, this pool habitat also had a greater distribution close to road. I conclude from this analysis that there were no strong negative effects of human disturbance on harlequin duck occupy and resource selection, but recommend that harlequin habitat near to human use areas be monitored closely. For my third objective I found that concentrations of corticosterone deposited in feathers grown just prior to reproduction predict reproductive success for that year. I did not find any predictive value of body condition or baseline corticosterone levels. The carry-over effects that I documented in the feathers grown during the prenuptial molt indicate that is an import period that reflects reproductive decision (may be 2 month separation from feather growth to egg lay). These 3 lines of inquiry identified important sources of annual reproductive variation and will help guide management and conservation efforts. I recommend further study to better understand important resources that harlequins select for on the breeding stream and intensive study of harlequin wintering habitat, especially prenuptial molt areas.

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