Midwest Fish & Wildlife Conference 2018

AUTHORS. Michael Joyce, University of Minnesota Duluth; John Erb, Pam Coy, Barry Sampson - Minnesota Department of Natural Resources; Ron Moen, University of Minnesota Duluth

ABSTRACT. Dispersal is a condition-dependent behavioral strategy with implications for gene flow, meta-population dynamics, and social structure. Many studies have focused on understanding the conditions that influence the strength and direction of density-dependence and sex-bias in animal dispersal. Although mating system and social structure are among the factors proposed to explain dispersal strategies, relatively few studies have tested for density-dependence or sex-bias in dispersal by solitary, territorial carnivores. Our objectives were to evaluate how age, sex, and population dynamics influence dispersal probability, distance, and timing in American martens, a solitary carnivore exhibiting intrasexual territoriality. We radiocollared 150 martens from 2008-2015 and used telemetry locations, annual marten abundance estimates, and annual prey indices to test whether dispersal was influenced by age, sex, population density, or per capita prey resource density. Juvenile martens dispersed more frequently and earlier than adults. Females were more likely to disperse than males, but there was no difference in dispersal distances or timing between sexes. Neither marten density nor per capita prey density influenced the probability that individual martens dispersed, but we captured more juveniles and a greater proportion of monitored martens dispersed in years with better recruitment. There was no relationship between dispersal distance and marten density or per capita prey density. However, the three longest dispersal distances observed occurred at the highest marten density. Martens tended to disperse during the two months following the short, intense harvest season, when there was a flux of vacant territories, or during late winter, when temperatures were warmer, snow was compacted, and energetic costs of thermoregulation and movement were lower. Our results provide evidence for the roles of social structure, harvest, and population dynamics on dispersal in martens. Our results also demonstrate the importance of considering both inter-annual variation in population and resource density when testing for density-dependence.

AUTHORS. Bradford Silet, Gary J. Roloff - Michigan State University; Eric Clark, Joseph Lautenbach, Russell Aikens, Aimee Baier, John Powell - Sault Ste Marie Tribe of Chippewa Indians; Steve Sjoren, Hiawatha National Forest

ABSTRACT. As American marten (Martes americana) move they respond to biotic and abiotic factors.  For species that are vulnerable to predation and trapping like marten, movement behaviors in response to weather and season can inform harvest regulations and research activities.  We examined the daily, seasonal, and weather related movements of marten in the Hiawatha National Forest (HNF) in the eastern Upper Peninsula of Michigan. We GPS collared 12 (11 males, 1 female) marten and attempted to collect a location every 15 minutes.  We downloaded 7,930 locations (660.8 locations/marten), and for each successive GPS fix we calculated average hourly rate of movement by season. To model abiotic factors affecting movement rates, we used hourly rate of movement as a dependent variable in generalized linear mixed models with fixed effects that included interpolated weather estimates from Daymet.  Individual marten and season were used as random effects in the models.  On average, we found that marten moved 13.3 m/min, and that hourly movement rates did not differ throughout a 24-hr day. We also found that marten moved significantly less in fall than winter, spring, and summer.  We failed to find a significant weather effect on marten movement rates, but limited evidence supported the hypotheses that daily movement rates increased as: 1) maximum daily temperatures decreased, and 2) as precipitation increased. Our results indicated that fall may be a difficult time to capture marten as movement rates are significantly lower, and that weather cannot be used to reliably predict when marten move.

AUTHORS. Angela Kujawa, Paul Keenlance, Alexandra Locher – Grand Valley State University; Robert Sanders, Little River Band of Ottawa Indians; Joseph Jacquot, Grand Valley State University

ABSTRACT. American marten (Martes americana) are mustelids used as indicators of healthy forest ecosystems. Marten were extirpated from Michigan’s lower peninsula (LP) in 1911 followed by reintroduction efforts in 1985-86. Marten are known to occur near reintroduction sites, but the full extent of their range and habitat preferences in the LP are unknown. Our objective was to create a resource selection function-based model for marten in Michigan’s northern LP to identify regions marten have a high probability of using. Marten in the Manistee National Forest (MNF) were fitted with VHF and GPS collars from 2011-2016 to collect data on habitat use. Kernel-based home-ranges were estimated for marten with at least 30 known locations; which provided a sample size of 18 individuals with a total of 7352 locations. Characteristics commonly associated with marten habitat selection, including highway density, percent canopy cover, stand age, basal area, elevation, and percent of deciduous, coniferous and mixed forest were measured within each home-range and surrounding available habitat. Using forward and backward selection the best fit logistic regression models were chosen and averaged. Marten resource selection was driven by percent canopy cover and percent of coniferous and mixed forest. Following model development, 50 hexagons with an average value within each high (1-0.67), medium (0.66-0.34), and low (0.33-0) probabilities of use were sampled using remotely-triggered cameras to validate our model. Hexagons were the average size of a female’s home-range (7.6km2) and cameras were placed near the center of each for three weeks. Marten were only detected in areas predicted to have a high probability of use, providing support for the model. Our model suggests that suitable habitat for marten is limited and fragmented within the LP. Management efforts should focus on maintaining mature pine stands with large diameter conifer trees with a dense canopy cover. 

AUTHORS. Christopher N. Jacques, Western Illinois University; Robert W. Klaver, U.S. Geological Survey; James S. Zweep, Western Illinois University; Shelli A. Dubay, University of Wisconsin-Stevens Point

ABSTRACT. Southern flying squirrels (SFS; Glaucomys volans) nest in naturally–formed cavities in snags and hardwoods found in mature, undisturbed forests. Intensive forest fragmentation of the Midwest United States limits the number of available nesting trees. We studied annual nest site selection patterns of SFS across fragmented landscapes of west-central Illinois. We used radio telemetry to examine nest tree use by 55 SFS (30 males, 25 females) captured during 2014–2016. Of 105 nest trees used by SFS, live trees and snags comprised 75% and 25%, respectively. Probability of diurnal nest tree use increased 1.08 (odds ratio = 1.075, 95% CI = 1.045–1.1061)/1 cm increase in DBH and by 1.50 (odds ratio = 1.496, 95% CI = 1.138–1.966)/1 unit increase in the number of overstory mast trees between random and nest tree habitat areas (i.e., 300 m2 circular plots). Similarly, probability of diurnal nest tree use increased 1.29 (odds ratio = 1.289, 95% CI = 1.075–1.544)/1 unit increase in the number of snags between random and nest tree habitat areas. Our results revealed no intersexual differences in patterns of nest site selection, which may reflect the tendency for SFS to compensate for reduced availability of key structural attributes (i.e., snags, overstory trees) across fragmented forests by exhibiting similar intersexual patterns of nest tree use. Additionally, patterns of diurnal nest tree use revealed near exclusive use of natural cavities located primarily in live trees, which may be attributed to a propensity of SFS to select cavities with small entrances and avoid cavities that have been enlarged by other species. Use of natural cavities for denning is encouraging, but also underscores the importance of unharvested hardwood forests in contributing essential habitat to SFS populations in fragmented forested landscapes.

AUTHORS. Christopher N. Jacques, Western Illinois University; Shelli A. Dubay, University of Wisconsin-Stevens Point; Bridget M. Walker, University of Wisconsin-Stevens Point; Robert W. Klaver, US Geological Survey

ABSTRACT. Environmental or intrinsic characteristics that predispose hosts to parasitic infections (and particularly to co-occurrence) are not well understood, but sex and age often influence prevalence and intensity of parasitic infections in hosts. Collectively, results from previous studies suggest that intersexual differences in hormonally-mediated immunosuppression and behavior may contribute to sex biases in parasitism. Southern flying squirrels (SFS; Glaucomys volans) are small-bodied, non-hibernating, communally nesting, rodents that occur in low densities across Midwestern landscapes and frequently defecate into substrate within communal nesting cavities. Thus, SFS are ideal organisms to evaluate several hypotheses related to host-parasite relations, including how parasite co-occurrence and sex-biased parasitism in hosts concurrently affect distributions of parasites. Of 52 SFS examined for parasites, prevalence of infection for Strongyloides robustus, Coccidia, and ectoparasites was 57.7%, 44.2%, and 46.2%, respectively. We documented similar patterns of infection with SFS harboring ectoparasites, in which case individuals also were infected with S. robustus (42%) or Coccidia (31%); 38% and 40% of SFSs that did not harbor ectoparasites also tested negative for S. robustus and Coccidia, respectively. Probability of infection with S. robustus increased 27.50 (OR = 27.500, 95% CI = 5.210–45.154) and 12.67 (OR = 12.667, 95% CI = 3.016–23.189) when animals also were infected with ectoparasites or Coccidia, respectively. We collected 107 ectoparasites from 52 squirrels, of which the morphology of 99 (92.5%) was consistent with the flea species Orchopeas howardi. Males were significantly more parasitized than females, and small males were more parasitized than large males. Because SFS exhibit plasticity in sexual dimorphism, sex differences in parasite loads may be attributable to immunosuppressive qualities of testosterone. Ectoparasite loads also may negatively influence body condition, and juvenile small males that are more susceptible to higher parasite loads may be unable to allocate as much energy to growth as large animals.

AUTHORS. Ryan G. Tebo, Farmland Wildlife Populations and Research Group, Minnesota Department of Natural Resources; Andrew S. Norton, Farmland Wildlife Populations and Research Group, Minnesota Department of Natural Resources

ABSTRACT. Minnesota small game hunters have recently voiced concerns that squirrel populations are in decline due to overharvest and liberal hunting regulations, namely on public hunting lands within daily travel distance of the St. Paul-Minneapolis metropolitan area. To address these concerns, the Minnesota Department of Natural Resources conducted a 2-year study comparing survival rates of squirrels on Whitewater Wildlife Management Area (WMA), where hunting is permitted, and at nearby Whitewater State Park (SP), where hunting is prohibited. We captured and radiocollared 107 squirrels at the WMA and 101 squirrels at the SP during from July 2015 - September 2016. We estimated cause-specific squirrel mortality by fitting hazard-based, interval-censored survival models using Bayesian methods that incorporated data augmentation techniques to address a high proportion of uncertain fates. Estimated yearly survival on the WMA was 0.251 (0.146 – 0.365), whereas survival on the SP was 0.493 (0.368 – 0.624). We further investigated the effects of sex, age, and distance to hunter access during the peak of the hunting season (mid-September – early November) on squirrels in the WMA. We found little evidence for differences in survival rates by age or sex during the peak hunting season. Estimated survival during this time was 0.553 (0.419 – 0.683) for males and 0.563 (0.427 – 0.694) for females. Estimated survival was 0.590 (0.451 – 0.721) and 0.586 (0.441 – 0.723) for adults and juveniles, respectively. We did find evidence that distance from hunter access impacted squirrel survival. Squirrel survival closest to hunter access during the peak of the season was 0.484 (0.345 – 0.623), whereas squirrel survival 1 km from access was 0.687 (0.489 – 0.848). We anticipate results from this study will help us define appropriate harvest strategies and hunting regulations for squirrels in Minnesota.

AUTHORS. Jordan J. Meyer, University of Wisconsin - Stevens Point; Robin E. Russell, USGS National Wildlife Health Center; Scott E. Hygnstrom, Jason D. Riddle, Christopher J. Yahnke - University of Wisconsin - Stevens Point

ABSTRACT. White-nose syndrome (hereafter; WNS) is a disease caused by an invasive fungal pathogen (Pseudogymnoascus destructans), which is traumatically affecting several cave-dwelling bat species of North America. WNS has spread to numerous counties in Wisconsin since its initial discovery in 2014. This disease has already begun to greatly impact half of the available bat species of Wisconsin, big brown bat (Eptesicus fuscus), little brown bat (Myotis lucifugus), northern long-eared bat (Myotis septentrionalis), and tri-colored bat (Perimyotis subflavus). Understanding how this disease could shift community dynamics regionally is a current focus of research. The Wisconsin Department of Natural Resources established 5 permanent long-term bat monitoring stations (LTBMS) at Cofrin Arboretum, Kemp Natural Resource Station, Schmeeckle Reserve, the Urban Ecology Center, and the University of Wisconsin - Madison Arboretum in the year 2007. These LTBMS record echolocation calls, which were automatically classified to species and then manually vetted. This study evaluates the site occupancy of Wisconsin’s bat species at these LTBMS using a hierarchal Bayesian multispecies model. By comparing the community dynamics prior to the 2014 discovery of WNS in Wisconsin to the years that follow, this study could greatly improve the understanding the impact that this disease poses as it encroaches across North America.

AUTHORS. Maarten J. Vonhof, Western Michigan University; Timothy C. Carter, Ball State University; Sudha Chaturvedi, NY State Department of Health; Charles D. Mackenzie, Michigan State University; Amanpreet Singh, NY State Department of Health; Rob R. Eversole, Western Michigan University

ABSTRACT. As white-nose syndrome (WNS) continues to increase in prevalence and expand across North America there is an urgent need to develop mechanisms and strategies to reduce mortality rates and limit transmission to new regions. Chitosan is naturally-occurring biopolymer with powerful antimicrobial and wound-healing properties, and is fully biocompatible, biodegradable, and nontoxic. Here we summarize the findings of our laboratory and field studies to test the efficacy of chitosan for the prevention and treatment of WNS. Our data show that concentrations of 0.1% chitosan or above completely inhibit growth of Pseudogymnoascus destructans (Pd), and have a fungicidal effect, killing over 95% of treated cells. Five times as much chitosan was required to prevent growth of other tested cave fungi (e.g., Kernia, Penicillium, Pseudorotium, Trichosporiella), suggesting that application of 0.1% chitosan may have reduced impacts on native bat and cave mycobiomes. Treatment of experimentally-infected bats with 0.1% chitosan in the laboratory did not result in lower Pd loads on wings or altered arousal behavior relative to infected controls. However, chitosan-treated bats had higher survival and reduced Pdpenetration and damage in the tissues of the muzzle, particularly in the nasal cavity and turbinates, relative to infected controls. In 2016-17 we initiated field trials in three sites in Illinois and Michigan, and we will provide an update on their progress. Overall, our studies show that chitosan is a promising tool to reduce Pd-induced tissue damage and mortality in bats, and one that could be tested as a fungicidal agent for site treatment.

AUTHORS. Keifer Titus, Timothy Carter - Ball State University Department of Biology; Scott Haulton, Indiana Department of Natural Resources Division of Forestry

ABSTRACT. Timber harvesting is an essential tool for habitat management of several wildlife species present on Indiana State forests, especially bats. Despite a long history of timber harvesting and forest management in the Midwest, there is a paucity of information regarding the immediate and long-term effects of these practices on forest dwelling bat species. Considering recent population declines of several cave dwelling bat species due to White-nose Syndrome across the eastern and Midwestern U.S., understanding community wide bat response to habitat management practices are of immense importance. To fully elucidate the ecological consequences of harvesting practices on the bat community, we acoustically surveyed 144 sites across the Morgan-Monroe and Yellowwood state forests in southern Indiana during the 2016-2017 summer seasons (May-August). As a part of the Hardwood Ecosystem Experiment, a long-term (100 yr.) ecological study, we used paired random sampling techniques to survey bat occupancy in four different harvest treatment types including clear-cuts, shelter wood cuts, single-tree selection cuts, and unharvested forests. Echolocation calls were recorded using Wildlife Acoustics SM2+ echolocation detectors and calls were identified using Bat Call ID v.2.7D (BCID). Over 55,000 call files were recorded over the course of the study. We used multi-season false-positive occupancy models to account for imperfect detection of bat species. Preliminary findings show evidence for equivocal relationships of occupancy between medium intensity harvests for northern long-eared (Myotis septentrionalis), Indiana (Myotis sodalis), and eastern red bats (Lasiurus borealis). Results will be discussed in full following complete analyses.

AUTHORS. Genelle Uhrig, University of Wisconsin-Milwaukee; Eric Clark, Sault Ste. Marie Tribe of Chippewa Indians Inland Fish and Wildlife Department; Emily Latch, University of Wisconsin-Milwaukee

ABSTRACT. In traditional capture-mark-recapture demographic studies, much effort is placed on trapping animals, marking, and then releasing them for subsequent recapture. This approach has many challenges, including coping with trap-happy or trap-averse animals and the amount of time and effort put into baiting and setting traps. We can circumvent these challenges by using some part of the animal that is naturally shed in the environment (e.g. fecal matter, fur, or feathers) to identify individuals with genetic techniques. Snowshoe hare (Lepus americanus) are a good candidate for this non-invasive sampling method as it is feasible to genetically identify individuals using DNA from a single fecal pellet. Our study aims to assess the demographic and genetic characteristics of declining snowshoe hare in the Hiawatha National Forest (Eastern portion) located in the Upper Peninsula of Michigan. Population declines are often attributed to climate change and the occurrence of environmental mismatch, in which snowshoe hare pelage does not match the surrounding environment and hares are easily seen by predators. As populations along the southern edge of a range are likely affected first, it is within these areas we predict genetic variation will be greatly impacted. Fecal pellets (n=269) were collected across 7 sites and genotyped at 10 microsatellite markers. Individuals were identified and density, genetic diversity, and patterns of genetic structure and variation among sites were estimated. This information is vital to inform the management and conservation of snowshoe hare populations in decline along the species' southern range.