Peter Pekins, Professor, Department of Natural Resources & the Environment, travels to Poland

Professor Peter Pekins travelled to the 7th International Moose Conference in Poland to discuss research and management issues concerning moose that range west from Eastern Europe through North America.The Bialowieza National Park and Forest in western Poland was the site of the 7th International Moose Conference where 150 biologists gathered to discuss research and management issues concerning moose that range west from Eastern Europe through North America. My travel to Poland was focused on: 1) moose research/management and serving as Chief Editor of ALCES a scientific journal dedicated to moose research and management, 2) learning about the special history of the wisent, or European bison, that was saved from extinction in the Bialowieza National Park and Forest in the early 1900s 3) reconnecting with close Norwegian colleagues who have supported a previous sabbatical as well as a number of IROP students from the Hamel Center

Effects of moose foraging on browse availability in New Hampshire deer yards

Food habits of moose (Alces alces) and white-tailed deer (Odocoileus virginianus) overlap in northern New Hampshire during autumn and winter. High moose and deer densities in deer yards, where deer may be confined for extended periods, could result in competition for limited deciduous forage. The purpose of this study was to investigate possible impacts by moose on browse availability in deer yards, and the potential effects on deer. Fifteen deer yards were studied in northern New Hampshire during spring and fall, 1990-91. Unbrowsed and browsed deciduous twigs, and deer and moose pellet groups were counted on 900 permanent plots to measure seasonal browse use and population density of deer and moose. Twig biomass availability and removal were estimated for each season in all areas. Combined data from all deer yards showed that unbrowsed biomass increased between spring 1990 and autumn 1990, and decreased between autumn 1990 and spring 1991. Moose browsed 7.2% of available food during autumn 1989 and winter 1990, 7.7% during autumn 1990, and 3.8% during winter 1991, accounting for 26.3%, 81.1%, and 17.6% of browsed biomass, respectively. One-year-old clearcuts adjacent to wintering areas were heavily browsed, particularly during the winter. Preferred moose foods during autumn were quaking aspen and mountain maple. Pin cherry and nannyberry were removed relative to availability. Moose have the potential to substantially reduce the availability of preferred deciduous browse (e.g. maples) of deer, and thus reduce the carrying capacity of deer yards. Specialized management in areas of high moose density may be warranted where clearcuts adjacent to deer yards provide the essential winter forage of deer

Identification and Density Estimation of American Martens (Martes americana) Using a Novel Camera-Trap Method

Camera-traps are increasingly used to estimate wildlife abundance, yet few studies exist for small-sized carnivores or comparing efficacy against traditional methods. We developed a camera-trap to identify the unique ventral patches of American martens (Martes americana). Our method was designed to: (1) determine the optimal trap configuration to photograph ventral patches; (2) evaluate the use of temporally clustered photographs to determine independence and improve identification; and (3) determine factors that influence identification probability. We tested our method by comparing camera- and live-trap density estimates using spatial capture–recapture (SCR) models. The ventral patches of radio-collared martens were most visible when traps were placed 15–20 cm above a feeding platform. Radio-collared martens (n = 14) visited camera-traps for long periods (median = 7 min) with long intervals between visits (median = 419 min), and visits by different martens at the same trap \u3c15 min apart was infrequent (n = 3) during both years. Similarly, there was complete agreement among observers that clustered photos of un-collared martens were always of the same individual. Pairwise agreement was high between observers; eight un-collared martens were identifiable by consensus on 90% (54 of 60) of recorded visits. Factors influencing identification probability were directly related to the time martens spent feeding at traps (β = 0.143, P = 0.01) and inversely proportional to the time that elapsed since traps were baited (β = −0.344, P = 0.006). Density estimates were higher and more precise for camera-trapping (0.60, 0.35–1.01 martens/km2) than live-trapping (0.45, 0.16–1.22 martens/km2), providing evidence that SCR density estimates may be biased when capture heterogeneity is present, yet cannot be accounted for due to small sample size. Our camera-trap method provides a minimally invasive and accurate tool for monitoring marten populations

Evaluating moose Alces alces population response to infestation level of winter ticks Dermacentor albipictus

Many wildlife populations are experiencing a variety of environmental pressures due to the direct and indirect consequences of a changing climate. In the northeast, USA, moose Alces alces are declining in large part because of the increasing parasitism by winter tick Dermacentor albipictus, facilitated by high host density and optimal environmental conditions. To test this hypothesis, and better understand the influence of this interaction on the stability of the regional population, we constructed a population viability model using data collected through comprehensive survival and productivity studies in 2002–2005 and 2014–2018 in northern New Hampshire. Years of heavy tick infestation (epizootics) saw a marked reduction in calf survival (\u3c 50%), adult calving (\u3c 60%), twinning rate (\u3c 5%) and complete loss of yearling productivity. We conducted population viability analysis using VORTEX ver. 10.2 to model this moose population for 40 years using mean demographics from both time periods, including environmental variation measured in the field during winter tick epizootic (2002, 2014, 2015, 2016) and non-epizootic (2003, 2004, 2005, 2017) years. This exercise highlights the influence of winter tick infestation on the trajectory of the population with the potential for rapid population growth or decline depending on the frequency of epizootics. We suggest a shift in moose management strategy focused on lowering moose density, assuming continued influence of climate change on the host-parasite relationship

EVALUATING THE USEFULNESS OF THREE INDICES FOR ASSESSING WINTER TICK ABUNDANCE IN NORTHERN NEW HAMPSHIRE

In New Hampshire, winter ticks (Dermacentor albipictus) probably have more influence on the moose (Alces alces) population than other mortality factors, and predicting the frequency of tick epizootics is an important management consideration. Weather, moose density, and habitat use influence abundance and distribution of winter ticks. We evaluated the usefulness of 3 techniques to index winter tick abundance in 3 regions with variable moose density: 1) flagging for tick larvae, 2) line-transect counts of ticks on harvested moose, and 3) roadside surveys of tick-induced hairloss on moose. Although counts of tick larvae from fall flagging were not significantly different between years or regions, absolute tick abundance was measurably different (>50%) relative to moose density and years. Tick abundance on harvested moose reflected annual and regional differences; in general, abundance was correlated positively with moose density and annual trends within regions were similar. Tick abundance was highest for calves and lowest for cows. Hair-loss surveys indicated that hair loss was generally related to moose density, and similar annual differences were reflected in all regions. We suggest measuring tick abundance on harvested moose and conducting annual roadside hair-loss surveys to create indices and threshold values useful in predicting an epizootic of winter ticks

Short-term fate of rehabilitated orphan black bears released in New Hampshire

We evaluated the release of rehabilitated, orphan black bears (Ursus americanus) in northern New Hampshire. Eleven bears (9 males, 2 females; 40–45 kg) were outfitted with GPS radio-collars and released during May and June of 2011 and 2012. Bears released in 2011 had higher apparent survival and were not observed or reported in any nuisance behavior, whereas no bears released in 2012 survived, and all were involved in minor nuisance behavior. Analysis of GPS locations indicated that bears in 2011 had access to and used abundant natural forages or habitat. Conversely, abundance of soft and hard mast was lower in 2012, suggesting that nuisance behavior, and consequently survival, was inversely related to availability of natural forage. Dispersal from the release site ranged from 3.4–73 km across both years, and no bear returned to the rehabilitation facility (117 km distance). Rehabilitation appears to be a valid method for addressing certain orphan bear issues in New Hampshire

USING SNOW URINE SAMPLES TO ASSESS THE IMPACT OF WINTER TICKS ON MOOSE CALF CONDITION AND SURVIVAL

Snow urine samples collected in northern New Hampshire, USA were used to measure urea nitrogen (UN) and creatinine (C) content to develop ratios for tracking the nutritional restriction of individual moose (Alces alces) through winter (2014–2017), inclusive of the adult winter tick (Dermacentor albipictus) engorgement period. Samples (n = 215) were collected from 55 moose (38 calves, 17 cows) on a twice monthly schedule from late January through snowmelt or calf mortality (March – early April). Early winter UN:C ratios from cows, surviving calves, and calves that ultimately died from infestation of winter ticks were similar and reflected a normal winter diet low in protein. A heightened UN:C ratio (> 3.5 mg/dL) was measured in March which aligned with peak feeding by adult winter ticks, and presumably reflected accelerated protein deficit associated with blood loss. This increase was not observed population-wide despite shared habitat, occurring only in calves with mortal weight loss and anemia associated with heavy winter tick infestation. Measurement of UN:C ratios from snow urine samples proved an effective method to measure the temporal impact of winter tick infestation, and March samples can support other metrics used to estimate calf mortality

TEMPORAL ASSESSMENT OF PHYSICAL CHARACTERISTICS AND REPRODUCTIVE STATUS OF MOOSE IN NEW HAMPSHIRE

Biological data collected from harvested moose (Alces alces) were analyzed to assess whether temporal change has occurred in the physical and reproductive condition of moose from 1988–2009 in New Hampshire. Measurements included age and field-dressed body weight of both sexes, number of corpora lutea (CL) and ovulation rate of females, and antler beam diameter (ABD) and antler spread of males. Similar data were obtained from Maine and Vermont for comparative analysis. The only significant changes (P <0.05) occurred in the yearling age class: mean body weight of both sexes, number of CL, and ABD all declined in New Hampshire. The current ovulation rate (~20%) and mean body weight (<200 kg) of yearling females in New Hampshire and Vermont were considered low. The declines measured in yearlings, yet relative stability in adults, are consistent with the presumption that winter ticks (Dermacentor albipictus) impact the productivity of moose populations through reduced calf survival and growth and fecundity of yearlings. Density-dependent factors related to habitat change are also discussed given the recent, rapid expansion of moose in the 3 states. Continued monitoring of physical parameters and productivity of harvested moose, particularly the yearling cohort, is warranted to better assess the relationships among winter ticks, habitat quality, and moose populations

ANALYSIS OF AGE, BODY WEIGHT AND ANTLER SPREAD OF BULL MOOSE HARVESTED IN MAINE, 1980-2009

Age, field-dressed body weight, and antler spread data collected from 11,566 harvested moose (Alces alces) were analyzed to assess whether temporal change has occurred in the physical characteristics of bull moose from 1980–2009 in Maine. The annual proportion and antler spread of trophy bulls (spread ≥ 137 cm; n = 851) were also analyzed. There was no evidence of a measurable decline in the body weight or antler spread of adult bull moose (≥1.5 years old), similar to findings in Vermont and New Hampshire in a recent >20 year temporal analysis. There was a slight increase in physical characteristics of yearlings that contrasted with the trend in New Hampshire and Vermont where it is speculated that parasitism by winter ticks (Dermacentor albipictus) reduces growth rate and recruitment by yearlings. The proportion of trophy bulls in the harvest declined proportionally ∼26% (9.3 to 6.9%) as harvest increased >2x from 1980–1987 to 2005–2009; however, the mean spread of trophy bulls declined by only 2% (P = 0.002). Additionally, there were no differences (P > 0.05) in the proportion of harvested bulls within each age class between 1980–1987 and 2005–2009, and the relatively stable proportion of mature bulls (>5 years old) in the harvest across time periods (30–44%) does not suggest selective harvest of older, trophy bulls. In the face of the declining regional population, continued monitoring of harvested moose is warranted to best manage the largest and longest harvested population in the northeastern United States

ANALYSIS OF AGE, BODY WEIGHT AND ANTLER SPREAD OF BULL MOOSE HARVESTED IN MAINE, 1980-2009

Age, field-dressed body weight, and antler spread data collected from 11,566 harvested moose (Alces alces) were analyzed to assess whether temporal change has occurred in the physical characteristics of bull moose from 1980–2009 in Maine. The annual proportion and antler spread of trophy bulls (spread ≥ 137 cm; n = 851) were also analyzed. There was no evidence of a measurable decline in the body weight or antler spread of adult bull moose (≥1.5 years old), similar to findings in Vermont and New Hampshire in a recent >20 year temporal analysis. There was a slight increase in physical characteristics of yearlings that contrasted with the trend in New Hampshire and Vermont where it is speculated that parasitism by winter ticks (Dermacentor albipictus) reduces growth rate and recruitment by yearlings. The proportion of trophy bulls in the harvest declined proportionally ∼26% (9.3 to 6.9%) as harvest increased >2x from 1980–1987 to 2005–2009; however, the mean spread of trophy bulls declined by only 2% (P = 0.002). Additionally, there were no differences (P > 0.05) in the proportion of harvested bulls within each age class between 1980–1987 and 2005–2009, and the relatively stable proportion of mature bulls (>5 years old) in the harvest across time periods (30–44%) does not suggest selective harvest of older, trophy bulls. In the face of the declining regional population, continued monitoring of harvested moose is warranted to best manage the largest and longest harvested population in the northeastern United States