Existing evidence on the effects of climate variability and climate change on ungulates in North America: a systematic map.

BACKGROUND: Climate is an important driver of ungulate life-histories, population dynamics, and migratory behaviors. Climate conditions can directly impact ungulates via changes in the costs of thermoregulation and locomotion, or indirectly, via changes in habitat and forage availability, predation, and species interactions. Many studies have documented the effects of climate variability and climate change on North America's ungulates, recording impacts to population demographics, physiology, foraging behavior, migratory patterns, and more. However, ungulate responses are not uniform and vary by species and geography. Here, we present a systematic map describing the abundance and distribution of evidence on the effects of climate variability and climate change on native ungulates in North America. METHODS: We searched for all evidence documenting or projecting how climate variability and climate change affect the 15 ungulate species native to the U.S., Canada, Mexico, and Greenland. We searched Web of Science, Scopus, and the websites of 62 wildlife management agencies to identify relevant academic and grey literature. We screened English-language documents for inclusion at both the title and abstract and full-text levels. Data from all articles that passed full-text review were extracted and coded in a database. We identified knowledge clusters and gaps related to the species, locations, climate variables, and outcome variables measured in the literature. REVIEW FINDINGS: We identified a total of 674 relevant articles published from 1947 until September 2020. Caribou (Rangifer tarandus), elk (Cervus canadensis), and white-tailed deer (Odocoileus virginianus) were the most frequently studied species. Geographically, more research has been conducted in the western U.S. and western Canada, though a notable concentration of research is also located in the Great Lakes region. Nearly 75% more articles examined the effects of precipitation on ungulates compared to temperature, with variables related to snow being the most commonly measured climate variables. Most studies examined the effects of climate on ungulate population demographics, habitat and forage, and physiology and condition, with far fewer examining the effects on disturbances, migratory behavior, and seasonal range and corridor habitat. CONCLUSIONS: The effects of climate change, and its interactions with stressors such as land-use change, predation, and disease, is of increasing concern to wildlife managers. With its broad scope, this systematic map can help ungulate managers identify relevant climate impacts and prepare for future changes to the populations they manage. Decisions regarding population control measures, supplemental feeding, translocation, and the application of habitat treatments are just some of the management decisions that can be informed by an improved understanding of climate impacts. This systematic map also identified several gaps in the literature that would benefit from additional research, including climate effects on ungulate migratory patterns, on species that are relatively understudied yet known to be sensitive to changes in climate, such as pronghorn (Antilocapra americana) and mountain goats (Oreamnos americanus), and on ungulates in the eastern U.S. and Mexico.

MORTALITY, SURVIVAL, AND SEROLOGIC RESULTS FOR ELK (CERVUS CANADENSIS) IN THE CUMBERLAND MOUNTAINS OF TENNESSEE, USA.

Comprehensive disease surveillance has not been conducted in elk (Cervus canadensis) in Tennessee, US, since their reintroduction to the state 20 yr ago. We identified causes of death, estimated annual survival, and identified pathogens of concern in elk at the North Cumberland Wildlife Management Area (NCWMA), Tennessee, US. In 2019 and 2020, we captured 29 elk (21 females, eight males) using chemical immobilization and fitted individuals with GPS collars with mortality sensors. Elk that died between February 2019 and February 2022 were necropsied to identify causes of death; these included disease associated with meningeal worm (Parelaphostrongylus tenuis; n=3), poaching (n=1), vehicular collision (n=1), legal hunter harvest (n=1), and unknown due to carcass degradation (n=3). Using data from GPS collars and known-fate survival models, we estimated an average yearly survival rate of 80.2%, indicating that survival had not significantly increased from soon after elk reintroduction (79.9%). We collected blood, tissue, feces, and ectoparasites opportunistically from anesthetized elk for health surveillance. We identified lone star ticks (Amblyomma americanum; n=53, 85.5%; 95% confidence interval [CI], 73.72-92.75), American dog ticks (Dermacentor variabilis; n=8, 12.9%; 95% CI, 6.13-24.40), and black-legged ticks (Ixodes scapularis; n=1, 1.6%; 95% CI, 0.08-9.83). We detected evidence of exposure to Anaplasma marginale (100%; 95% CI, 84.50-100.00), Leptospira interrogans (70.4%; 95% CI, 49.66-85.50), Toxoplasma gondii (55.6%; 95% CI, 35.64-73.96), epizootic hemorrhagic disease virus (51.9%; 95% CI, 32.35-70.84), and Theileria cervi (25.9%; 95% CI, 11.78-46.59). Johne's disease (Mycobacterium avium subsp. paratuberculosis) is potentially established within the population, but has not been previously documented in eastern elk populations. Disease associated with P. tenuis was a primary cause of death, and more research is needed to understand its ecology and epidemiology. Research to determine population implications of other detected pathogens at the NCWMA is warranted.

EVALUATING THE EFFICACY OF NONINVASIVE FECAL SAMPLING FOR PREGNANCY DETECTION IN ELK (CERVUS CANADENSIS).

Elk (Cervus canadensis) were reintroduced to Tennessee, USA in the early 2000s, with limited reproductive monitoring since initial release. We assessed the efficacy of noninvasive sampling for determining pregnancy using invasive (capture) and noninvasive (fecal collection in the field) techniques at the North Cumberland Wildlife Management Area (NCWMA), Tennessee. We captured 20 female elk 2019-2020, used pregnancy-specific protein B (PSPB) in blood to determine pregnancy and compared results to fecal progesterone metabolite (FPM) concentrations using two commercially available enzyme immunoassay (EIA) kits. Based on PSPB concentrations, 8/11 and 3/4 of captured adult elk (≥2.5 yr of age) were pregnant in 2019 and 2020, respectively; no 1.5-yr-old elk were pregnant (n=5). Using the progesterone EIA kit, FPM concentrations were x̄=192.84±38.63 ng/g (95% CI, 96.48-289.20) for nonpregnant and x̄=536.17±74.98 ng/g (95% CI, 375.97-696.36) for pregnant captured females. For the progesterone metabolite kit, FPM concentrations were x̄=188.16±43.39 ng/g (95% confidence interval [CI], 76.63-299.69) for nonpregnant and x̄=693.52±126.52 ng/g (95% CI, 407.31-979.72) for pregnant captured females. From February to May 2019, we collected 357 fecal samples in 65 areas across 489.62 km2 of the NCWMA. Using extracted DNA and analysis of 15 microsatellites, we identified 62 unique individuals from 128 female fecal samples collected on the landscape. We categorized females from landscape-collected feces as nonpregnant (35.5-40.3%; Metabolite-EIA kits), undetermined (1.6-6.5%; Metabolite-EIA kits), or pregnant (62.9-53.2%; Metabolite-EIA kits) based on a 95% CI of captured female FPM concentrations, giving an overall pregnancy rate of 53.2% using the recommended EIA kit. The pregnancy rate in sexually mature females may be higher, as it was not possible to distinguish age classes of landscape-collected fecal samples; therefore, some may have been from younger age classes not expected to be pregnant. Analysis of FPM may be useful at a population level to detect pregnancy.

Toxoplasma gondii contamination at an animal agriculture facility: Environmental, agricultural animal, and wildlife contamination indicator evaluation.

Toxoplasma gondii is a parasite of significant public health importance. We attempted to detect T. gondii contamination and assess advantages and disadvantages of contamination indicators through surveilling soil, wildlife, cats (Felis catus), and cows (Bos taurus) on a farm in Tennessee, U.S. in 2016 and 2017. Twenty-two soil samples were collected from the farm and subjected to oocyst flotation, DNA extraction, and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) targeting 18S ribosomal RNA (18S rRNA) gene to detect and identify T. gondii. Three samples (13.6%) were positive for the parasite; however, T. gondii DNA was not consistently detected from repeated tests. Blood samples were collected from small mammals, cats, and mesopredators live-trapped on the farm, and serum from 30 of the farm's cows were obtained. Serological testing by the modified agglutination test (MAT; cutoff 1:50) found 2.5% (1/40) of small mammals, 52.9% (9/17) of raccoons (Procyon lotor), and 50% (1/2) of domestic cats were seropositive for T. gondii antibodies. No antibodies were found in 16 opossums (Didelphis virginiana), two skunks (Mephitis mephitis), and 30 cows. Small mammal tissue samples were subjected to PCR-RFLP detection. Four out of 29 (13.7%) tissue samples were positive for T. gondii; however, T. gondii DNA was not consistently detected during repeated PCR-RFLP testing. Our results indicate the ability to detect T. gondii varies greatly by contamination indicator. We found detection of soil oocysts to be challenging, and results suggest limited utility of the method performed. The ability to detect T. gondii in animals was highly variable among species. Our research emphasizes the importance of a holistic approach when surveilling for T. gondii to compensate for shortcomings of each contamination indicator. Future research should be conducted to further investigate the most effective T. gondii surveillance methods and species with increased sample sizes at other agricultural facilities.

Survey of Baylisascaris spp. in Eastern Tennessee Wildlife and Detection of Baylisascaris spp. Eggs in Virginia Opossum ( Didelphis virginiana) Feces.

We analyzed 69 eastern Tennessee wildlife samples for Baylisascaris spp. during 2011. The prevalence of Baylisascaris spp. in raccoons ( Procyon lotor) was 16% (8/49), an increase compared to previous surveys in this region. One Virginia opossum ( Didelphis virginiana) had eggs in its feces, indicating that opossums can play a role in Baylisascaris spp. transmission.