Paul Keenlance

Factors Influencing Homesite Selection by Gray Wolves in Northwestern Wisconsin and East-Central Minnesota

One of the most critical aspects of population dynamics in any animal species is the birth and successful rearing of young. Therefore, understanding the characteristics of areas where wolves give birth and rear pups (den and rendezvous sites) is important for proper management. In the Great Lakes region, the gray wolf has made a remarkable recovery, from a small remnant population in northeastern Minnesota to the recolonization of most of northern Wisconsin and the Upper Peninsula of Michigan. In this chapter, we review relevant literature on wolf dens and rendezvous sites and attempt to determine those factors most critical in the selection of homesites in the upper Great Lakes region.

SEROSURVEY, HEMATOLOGY, AND CAUSES OF MORTALITY OF FREE-RANGING AMERICAN MARTENS (MARTES AMERICANA) IN MICHIGAN

Abstract:  To better understand the clinical pathology, diseases, and causes of mortality of reintroduced American martens (Martes americana) in Michigan, a study was conducted from 2011 to 2015 in the Upper and Lower Peninsulas of Michigan. Samples obtained from live trapping (n = 58) or harvested carcasses (n = 34) were serologically tested for select pathogens. Antibodies against Toxoplasma gondii and canine distemper virus were detected in 58 and 3.4% of samples, respectively. All samples were seronegative for Leptospira spp. and negative for Dirofilaria immitis antigen. Urine samples tested for Leptospira spp. via immunofluorescent antibody assay (n = 7), polymerase chain reaction (n = 6), or both (n = 3) were all negative. Parvovirus DNA was detected in 9.1% of small intestine samples (n = 22) collected from carcasses and in 3.7% of fecal samples (n = 27) collected during live trapping. Complete blood counts (n = 64) and serum biochemistries (n = 63) were obtained from 49 live-trapped martens. Biochemical parameters found to be significantly different (P < 0.05) between genders were calcium, creatinine, glucose, and phosphorus. There was no significant difference between genders for any hematologic parameter. Significant differences (P < 0.05) between summer and winter seasons were found in total estimated white blood cell count, neutrophils, lymphocytes, monocytes, alkaline phosphatase, bicarbonate, calcium, creatinine, globulin, glucose, phosphorus, potassium, sodium, and total protein. There was no significant difference in blood cell count or serum biochemistry values between radio-collared (n = 17) and noncollared (n = 47) martens. Animals seropositive for T. gondii were found to have significantly higher (P < 0.05) eosinophil and globulin levels than seronegative animals. The primary natural cause for mortality of radio-collared American martens was predation. Histologic examinations revealed a high percentage (60%) of martens with verminous or granulomatous pneumonia.

Mechanical thinning to restore oak savanna promoted predator assemblages of gypsy moth pupae in Michigan

The United States Forest Service conducted an oak savanna restoration using thinning and prescribed burning in the Manistee National Forest in Michigan to provide additional habitat for species dependent on this rare community type, including the Karner blue butterfly (Lycaeides melissa samuelis). Because the Karner blue butterfly is a federally endangered species, managers cannot spray Bt‐k (Bacillus thurigiensis var kurstaki) in areas undergoing restoration to control exotic invasive defoliators, such as European gypsy moths (Lymantria dispar). Although gypsy moths are invasive in North America, several native predators, such as white‐footed mice (Peromyscus leucopus), other small mammals and invertebrates, help keep gypsy moth populations at nondestructive levels. The present study investigated whether the small mammal community and gypsy moth predation rates were affected by the type of mechanical forest thinning method (bulldozer, masticator, shear cutter) used during an oak savanna restoration at two sites in Michigan within the suppression zone in 2010 and 2011. Predation rates on gypsy moth pupae were higher in bulldozer and shear cutter thinned compared with control plots at both sites in 2010. White‐footed mice relative abundance was significantly higher in thinned compared with control plots at one site in 2010 and 2011. Thinning maintained or promoted white‐footed mice abundance, which will maintain or enhance predation on gypsy moth pupae during oak savanna restoration.

EFFECTS OF LIVE-TRAPPING AND ISOFLURANE ANESTHESIA ON FREE-RANGING AMERICAN MARTENS (MARTES AMERICANA)

Abstract Seventy-two free-ranging American martens (Martes americana) in Michigan, US were immobilized using isoflurane from 2011 to 2015. In total, 129 anesthetic procedures were performed with no mortalities. Hypothermia and hyperthermia were the most common anesthetic complications, and the mean rectal temperatures were significantly higher during summer than in winter. Dental abnormalities were common; the majority of abnormal findings were broken or discolored teeth attributed to previous dental trauma and were not trap-induced. Blood (n=72) was analyzed from 53 martens for venous blood gas, lactate, hematocrit, and/or selected serum biochemistry analytes. Lactate concentration was measured by two different devices (VetScan i-STAT 1 and Lactate Plus) and compared for clinical agreement for 26 samples. Both methods for lactate measurement provided statistically similar results. Using domestic feline reference ranges, the acid-base status and relative arterial oxygen saturation of anesthetized martens in this study were normal as determined by blood pH and pulse oximetry, respectively. Serum biochemistry parameters, multiple environmental parameters, and marten-specific attributes were evaluated for their influence on lactate in American martens using linear regression and an information-theoretic approach with model averaging. Blood urea nitrogen was in all of the top models and was positively related to lactate (β=0.02, 95% confidence interval: 0.00–0.04). Initial body temperature, ambient temperature, and time from trap discovery until immobilization of martens were informative predictors for lactate level. Recommendations for the live-trapping and isoflurane anesthesia of free-ranging martens include using caution during warmer summer months, minimizing disturbance prior to induction, monitoring lactate in addition to vital rates, and being prepared to prevent or treat both hypothermia and hyperthermia during any time of year.

Genetic diversity of reintroduced American martens in Michigan’s Lower Peninsula

Reintroductions are an important conservation and management technique used to restore extirpated populations. Negative genetic consequences (e.g., diversity loss, bottlenecks, inbreeding) are often an unintentional result of reintroductions, due to a small number of founders or suboptimal habitat at release sites. American martens (Martes americana) were extirpated from Michigans Lower Peninsula in 1911 due to habitat loss and unregulated trapping. Martens were reintroduced into 2 areas of the Lower Peninsula in 1985–1986. The Lower Peninsula reintroduction was characterized by a relatively small number of founders (85 individuals) released into 2 geographically disparate, fragmented sites. We genotyped martens sampled at the 2 release sites approximately 20–25 years since reintroduction, using 11 microsatellite loci. We detected low average allelic richness (3.92 alleles per locus), moderate levels of inbreeding (mean FIS = 0.106), and multiple loci with significant heterozygote deficiencies. Effective population size estimates were small, ranging between 6 and 27 individuals depending on the estimator and the sample group. We also detected significant population structuring between the release sites (FST = 0.093 using the most recent sample). With small population size and limited to no gene flow, we predict the 2 Lower Peninsula marten populations will continue to diverge and potentially further lose genetic diversity. This study highlights the importance of long-term genetic monitoring of reintroduced populations.

Resting Site Characteristics of American Marten in the Northern Lower Peninsula of Michigan

Abstract American marten are associated with forests that are characteristically late successional, closed canopy, and diverse in structure; these attributes meet their habitat requirements and provide resting sites. However, the small populations of marten in Michigans Northern Lower Peninsula face modern habitat conditions that are fragmented and considerably altered from presettlement environments. Resting site structures are required habitat components that are used daily and provide protection from predation and inclement weather but may be limiting and require active management to preserve. We identified resting site characteristics of American marten in the Manistee National Forest from May 2011 to December 2013. Twenty-five marten (15 male and 10 female) were monitored to identify resting sites. We identified 522 unique resting site structures; tree cavities (n = 255, 48.9%), branches (n = 162, 31%), and nests (n = 90, 17.2%) were most commonly observed. During the summer (April–September) marten used more exposed tree branches (41.8%); while in the winter (October–March) they used more cavities (64.5%). Marten used structures that were associated with high percent canopy closure (≥67%). Resting sites were found in live trees 86% of the time, and the three predominant species included oak (Quercus spp.), maple (Acer spp.), and red pine (Pinus resinosa). Trees used as resting sites had significantly larger mean diameter at breast height (DBH) than the average DBH of nonresting site trees found at resting site locations (U′ = 268721, P = < 0.001). The average stand basal area (x¯ = 33.92 ± 9.04 m2 ha) found in resting site plots was significantly larger than that found at control plots (x¯ = 31.10 ± 8.69 m2 ha, P = 0.007). Maintaining complex forest structure, abundant CWD, high percent canopy closure and high basal area should be considered when managing for marten. Silvicultural techniques that promote tree species diversity, older tree age classes, and retention of CWD are all important factors to consider when managing for marten.