Alces (A Journal Devoted to the Biology and Management of Moose)
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SIMULATING SELECTIVE HARVEST AND IMPACT ON AGE STRUCTURE AND HARVEST EFFICIENCY OF MOOSE IN SWEDEN
Get PDFI simulated selective harvest strategies of moose (Alces alces) using antler point restrictions and protection of cows with calves to assess the impact of these strategies on population age structure and potential harvest efficiency (proportion of allowed shooting opportunities). The post-hunt, adult bull:cow ratio was held constant throughout the simulations, but age structure of the bull cohort was allowed to vary. The simulation showed that protecting bulls with few antler points (<5) reduced the average bull age in the post-hunt population, whereas protecting bulls with more points (4 – 8) yielded a higher average age. Regardless of type, restrictions caused a measurable drop in harvest efficiency, and subsequently, substantially more hunting days to achieve the harvest quota. Only 33% and 55% of the bulls in the population were eligible for harvest under the <5 points and 4-8 points restrictions, respectively. For cows, the post-hunt, average age was unaffected when cows accompanied by calves were protected during the first 3 weeks; likewise, harvest efficiency was unaffected by harvest restrictions on cows. However, restrictions protecting reproductive cows reduced harvest efficiency of calves, making it more difficult to reach calf harvest quotas. I suggest that antler point and cow hunting restrictions be abandoned in favour of sex-differentiated harvest quotas
SEASONAL VARIATION OF NUTRITIONAL HORMONES IN CAPTIVE FEMALE MOOSE
Get PDFThe health status of animals may be inferred from the patterns of hormonal concentrations and other chemical characteristics in blood samples. Baseline endocrine data representing the nutritional and reproductive condition of moose are currently unknown. In this study, we examined the seasonal patterns of 3 nutritional hormones (leptin, ghrelin, insulin-like growth factor-1) in 3 captive, non-pregnant female moose (Alces alces) fed a maintenance diet from November to August. Plasma concentrations for leptin, ghrelin, and IGF-1 averaged 1.36 ± 0.81 ng/mL, 0.229 ± 0.110 ng/mL, and 114.0 ± 30.5 ng/mL, respectively; only ghrelin displayed a seasonal change. Plasma ghrelin concentration was significantly elevated (P < 0.001) during winter months suggesting it may be sensitive to seasonal changes and indicative of nutritional status
COMBINING PHOTOGRAPHY AND A GEOGRAPHIC INFORMATION SYSTEM TO MEASURE WINTER BROWSE USE
Get PDFBrowse use surveys such as the twig-length method typically used to assess browsing by ungulates are time-consuming and costly. Here, we describe a modification of the twig-length method that utilizes digital photography and a Geographic Information System (GIS) technique to quantify browse shoot removal. Linear regression analysis indicated that the cumulative shoot length (cm) and biomass removal (g) estimated with our indirect method was similar to direct measurements on Scouler’s willows (Salix scouleriana). Our results suggest that this indirect browse assessment procedure could reduce field time, presumably increase sample size and efficiency, and create a photographic record of each plant for long-term assessment of moose (Alces alces) browsing
YUKON MOOSE: II. RANGE SIZES, MOVEMENT RATES, AND USE OF ELEVATION AND LAND COVER BY MALES AND FEMALES
Get PDFMoose (Alces alces), as a focal species in many northern communities, are increasingly subjected to anthropogenic activities. We studied range use by moose (males and females with and without calves) to enable more effective land-use planning in south-central Yukon. We detected seasonal differences in range sizes, movement rates, and use of elevation and land cover by global positioning system (GPS)-collared individuals, reflecting the responses of individuals to changing resource availability that is characteristic of boreal landscapes. During winter, moose in the South Canol area generally used smaller ranges at lower elevations and moved at lower rates within them, presumably limited by snow depths. They moved up in elevation throughout summer, reaching maximum elevations during rut and early winter. Moose used conifer stands, which were prevalent on the landscape, more than any other land-cover class throughout the year. Their use of upland and lowland shrub classes varied with season, with highest combined use of shrub-dominated land cover in early and late winter, likely reflecting the importance of shrubs as winter forage. We were unable to identify significant differences between the sexes or relative to reproductive status (i.e., calf presence). Differences between these groups in meeting requirements for forage and cover may be more discrete at the finer scale of microsite characteristics
PERSISTENT ORGANIC POLLUTANTS IN THE LIVERS OF MOOSE HARVESTED IN THE SOUTHERN NORTHWEST TERRITORIES, CANADA
Get PDFMoose (Alces alces) are an important traditional and spiritual resource for residents of the southern Northwest Territories and local residents are concerned about contaminants that may be present in the country foods they consume. As part of a larger program looking at contaminants in moose organs, we collected liver samples from moose harvested in two separate but adjoining regions within the Mackenzie River drainage area, the Dehcho and South Slave. We analyzed liver samples for a wide range of persistent organic pollutants (POPs) including polychlorinated biphenyls (PCBs), DDT related compounds, toxaphene, brominated diphenyl ethers (PBDEs) and perfluorinated alkyl substances (PFASs). Overall concentrations of major groups of POPs (total (Σ) PCBs, ΣPBDEs, ΣPFASs were consistently low (generally < 2 ng/g wet weight) in all samples and comparable to the limited data available from moose in Scandinavia. PFASs were the most prominent group with geometric means (range) of 1.3 (0.81–2.5) ng/g ww in the Dehcho and 0.93 (0.63–1.2) ng/g ww in the South Slave region. Decabromodiphenyl ether (BDE-209) was the most prominent PBDE congener, similar to that found in other arctic/subarctic terrestrial herbivores. In general, BDE-209 and PFASs, which are particle-borne and relatively non-volatile, were the predominant organic contaminants
YUKON MOOSE: I. SEASONAL RESOURCE SELECTION BY MALES AND FEMALES IN A MULTI-PREDATOR BOREAL ECOSYSTEM
Get PDFMoose (Alces alces) in Yukon experience an extreme range of thermal conditions, highly variable snow depths, natural and anthropogenic disturbances, predation by wolves and grizzly bears, and hunting pressure. Our objective was to identify variables that best explained habitat-selection patterns of moose in south-central Yukon for use in land-use planning and impact assessment. We evaluated selection of land-cover class, elevation, aspect, predation risk, and harvest vulnerability using resource selection functions. We created pooled models for males and females by averaging models for individuals by sex and season. Selection of shrub-dominated land cover highlighted the importance of forage accessibility throughout the year. Selection for elevation, aspect, and cover changed throughout the year, as influenced by climatic conditions. By selecting mixed cover types during calving and summer, female moose presumably balanced needs for both cover and forage. Males minimized harvest vulnerability during rut. Moose, in general, demonstrated highly variable habitat selection; however, consistent individual responses between sexes supported trends identified by pooled selection coefficients, as well as detected trends among males and females. The greatest amount of individual variation occurred during the growing season and the least amount during late winter, suggesting that climatic factors limited the options available to moose at a critical time of the year
THE EFFECTS OF SEX, TERRAIN, WILDFIRE, WINTER SEVERITY, AND MATERNAL STATUS ON HABITAT SELECTION BY MOOSE IN NORTH-CENTRAL ALASKA
Get PDFHabitat selection is a central component of the ecology of individual animals as it affects body condition, survivorship, and reproductive output. We instrumented male and female moose (Alces alces) in north-central Alaska with GPS radio-collars to assess factors we hypothesized were important to their habitat selection. Using synoptic modeling techniques, we found that models with more covariates were better predictors of moose habitat selection than more simplistic models. As expected, moose selected for habitats with high canopy cover and/or that typically have abundant forage such as 11-30 year old burned areas. However, we detected differences in habitat selection between sexes, seasons (i.e., winter versus summer), during winters of varying severity, and females with differing maternal status. During winter males moved to lower elevation areas, presumably to avoid greater snow depths, whereas females remained at relatively similar elevations. Females selected burned habitat and areas that received higher amounts of solar radiation. We found that all moose selected for lower elevation habitats closer to rivers during moderate and severe winters, but elevation was not a strong influence during mild winters. We found that females with calves avoided riparian habitats and selected areas with more forested habitat than females without calves during both summer and winter. This suggests a trade-off between maximizing forage intake and reducing predation risk for their offspring. Our and similar data are useful to improve moose management strategies and provide a benchmark against which the impacts of climate change and industrial development are assessed in this rapidly-changing region
FECUNDITY AND SUMMER CALF SURVIVAL OF MOOSE DURING 3 SUCCESSIVE YEARS OF WINTER TICK EPIZOOTICS
Get PDFMoose (Alces alces) populations in northern New Hampshire and western Maine experienced 3 successive years of high winter tick infestations (epizootics) in 2014–2016 that resulted in late-winter calf mortality rates >70%. To assess productivity in these populations, we measured fecundity rates of yearling and adult cow moose, and neonatal and summer calf survival. Parturition, fecundity, and survival were measured via direct observation by stalking VHF and GPS radio-collared cows (n = 177) in May-August, 2014–2016. Calving rates for yearlings and adults averaged 0 and 57%, respectively; there was no twinning documented. Summer calf survival to August was high overall (83%), with 85% of the mortality occurring in the first week of life. Calving and twinning rates declined since last measured in New Hampshire in 2002–2005 and were below the North American average; conversely, summer survival of calves was considered normal. Given that optimal habitat has increased in the past 15 years in the study area that is dominated by commercial forestry, lower productivity is presumably related to the additive impacts of successive winter tick epizootics on year-round condition of cows
MOOSE AND DEER POPULATION TRENDS IN NORTHWESTERN ONTARIO: A CASE HISTORY
Get PDFMany interrelated factors contribute to the rise and fall of white-tailed deer (Odocoileus virginianus) and moose (Alces alces) populations in the mixed boreal forests of eastern North America where these species often cohabit. A question not satisfactorily answered is why do moose populations periodically decline in a pronounced and prolonged way while deer populations continue to do well during times when habitat conditions appear good for both? Long-term historical data from the Kenora District of northwestern Ontario, Canada provided an opportunity to better understand temporal relationships between trends in deer and moose numbers and landscape-level habitat disturbances, ensuing forest succession, climate, predators, and disease. Over the past 100 years, moose and deer have fluctuated through 2 high-low population cycles. Deer numbers were high and moose numbers were low in the 1940s and 50s following a spruce budworm (Choristoneura fumiferana) outbreak. By the early 1960s, deer trended downwards and remained low during an extended period with frequent deep-snow winters; as deer declined, moose recovery was evident. Moose increased through the 1980s and 1990s as did deer, apparently in response to considerable habitat disturbance, including another spruce budworm outbreak and easier winters. However, despite conditions that were favourable for both species, moose declined markedly beginning in the late 1990s, and by 2012 were at very low levels district-wide while deer numbers remained high. Despite the moose decline being coincident with a short-lived winter tick (Dermacentor albipictus) epizootic in the early 2000s and increasing numbers of wolves (Canis lupus), we argue that the meningeal worm (Parelaphostrongylus tenuis) likely played a major role in this moose decline
THE STATUS AND MANAGEMENT OF MOOSE IN NORTH AMERICA - CIRCA 2015
Get PDFBoth declining and increasing moose (Alces alces) populations have been reported across North America over the last decade. We surveyed all jurisdictions with extant moose populations to determine the extent of these population trends. In 2014–2015, the North American moose population was estimated at ~1,000,000 animals distributed in 30 jurisdictions, which is unchanged since the turn of the century. Populations occurred in 12 Canadian provinces or territories, and in at least 18 states. In the past 5 years, moose density is believed to be increasing in 9, relatively stable in 8, and declining in 11 jurisdictions; estimates of change were unavailable in 2 jurisdictions. In 2014–2015, an estimated 425,537 licensed moose hunters harvested 82,096 moose in 23 jurisdictions. Hunter numbers increased by 39,118, whereas total harvest remained virtually unchanged from a decade earlier. Harvests by Indigenous and subsistence users, although largely unquantified, are believed substantial and important to quantify in certain jurisdictions. A variety of active and passive harvest strategies used to manage moose are discussed