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1. ASSESSING MOOSE HUNTER DISTRIBUTION TO EXPLORE HUNTER COMPETITION

   Hasbrouck, T.R. (August 2020, Alces)

   null (Ed.)

   Traditional values, motivations, and expectations of seclusion by moose (Alces alces) hunters, more specifically their distributional overlap and encounters in the field, may exacerbate perceptions of competition among hunters. However, few studies have quantitatively addressed overlap in hunting activity where hunters express concern about competition. To assess spatial and temporal characteristics of competition, our objectives were to: 1) quantify temporal harvest patterns in regions with low (roadless rural) and high (roaded urban) accessibility, and 2) quantify overlap in harvest patterns of two hunter groups (local, non-local) in rural regions. We used moose harvest data (2000–2016) in Alaska to quantify and compare hunting patterns across time and space between the two hunter groups in different moose management areas. We created a relative hunter overlap index that accounted for the extent of overlap between local and non-local harvest. The timing of peak harvest was different (P < 0.01) in urban and rural regions, occurring in the beginning and middle of the hunting season, respectively. In the rural region, hunter overlap scores revealed a concentration in 20% of the area on 16–20 September, with 50% of local harvest on 33% of the area and 54% of non-local harvest on 18% of the area. We recommend specific management strategies, such as lifting the air transportation ban into inaccessible areas, to redistribute hunters and reduce overlap and concerns of competition in high-use areas. We also encourage dissemination of information about known hotspots of hunter overlap to modify hunter expectations and subsequent behavior. Our hunter overlap index should prove useful in regions where similar concerns about hunter competition, hunter satisfaction, and related management dilemmas occur. 

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2. Changing snow conditions are challenging moose ( Alces alces ) surveys in Alaska

   https://doi.org/10.1002/wsb.1555  

   Brinkman, Todd J; Kellie, Kalin A; Reinking, Adele K; Liston, Glen E; Boelman, Natalie T (December 2024, Wildlife Society Bulletin)

   Abstract Snow conditions are changing rapidly across our planet, which has important implications for wildlife managers. In Alaska, USA, the later arrival of snow is challenging wildlife managers' ability to conduct aerial fall (autumn) moose (Alces alces) surveys. Complete snow cover is required to reliably detect and count moose using visual observation from an aircraft. With inadequate snow to help generate high‐quality moose survey data, it is difficult for managers to determine if they are effectively meeting population goals and optimizing hunting opportunities. We quantified past relationships and projected future trends between snow conditions and moose survey success across 7 different moose management areas in Alaska using 32 years (1987–2019) of moose survey data and modeled snow data. We found that modeled mean snow depth was 15 cm (SD = 11) when moose surveys were initiated, and snow depths were greater in years when surveys were completed compared to years when surveys were canceled. Further, we found that mean snow depth toward the beginning of the survey season (1 November) was the best predictor of whether a survey was completed in any given year. Based on modeled conditions, the trend in mean snow depth on 1 November declined from 1980 to 2020 in 5 out of 7 survey areas. These findings, coupled with future projections, indicated that by 2055, the delayed onset of adequate snow accumulation in the fall will prevent the completion of moose surveys over roughly 60% of Alaska's managed moose areas at this time of the year. Our findings can be used by wildlife managers to guide decisions related to the future reliability of aerial fall moose surveys and help to identify timelines for development of alternate measurement and monitoring methods. 

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3. AVAILABILITY AND USE OF MOOSE BROWSE IN RESPONSE TO POST-FIRE SUCCESSION ON KANUTI NATIONAL WILDLIFE REFUGE, ALASKA

   Julianus, E. (August 2019, Alces)

   null (Ed.)

   Wildfire is a prominent landscape-level disturbance in interior Alaska and associated vegetation changes affect quantity and quality of moose (Alces alces) habitat. These changes are important to land and wildlife managers responsible for managing habitat and ensuring sustained yield of game species such as moose. Considering the changing fire regime related to climate change, we explored post-fire dynamics of moose habitat to broaden understanding of local habitat characteristics associated with wildfire on the Kanuti National Wildlife Refuge in interior Alaska. We studied 34 sites in different aged stands (2005 burn, 1990 burn, 1972 burn, and unburned in the last 80 years) in August 2012 and 2013 to estimate summer browse density, biomass production, and browse use, and revisited each site the following March to estimate winter browse availability and offtake. We also used location data from 51 radio-collared moose to quantify use of burns on the Kanuti National Wildlife Refuge. We found that summer density and biomass of preferred browse was highest at sites in the 1990 burn, although use of burns varied seasonally. Despite high biomass in the most recent 2005 burn, radio-collared moose avoided burns <11 years old in summer and had preference for older stands (>30 years old). Winter browse offtake was highest in the 1990 and 1972 burns despite relatively high biomass available in the 2005 burn. The disparate use of burns, particularly low use of the 2005 burn, likely reflected a combination of influences including species composition and preference, predator avoidance strategies, a low density moose population, and historic moose distribution patterns. 

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4. Enhanced shrub growth in the Arctic increases habitat connectivity for browsing herbivores

   https://doi.org/10.1111/gcb.15104  

   Zhou, Jiake; Tape, Ken_D; Prugh, Laura; Kofinas, Gary; Carroll, Geoff; Kielland, Knut (April 2020, Global Change Biology)

   Abstract Habitat connectivity is a key factor influencing species range dynamics. Rapid warming in the Arctic is leading to widespread heterogeneous shrub expansion, but impacts of these habitat changes on range dynamics for large herbivores are not well understood. We use the climate–shrub–moose system of northern Alaska as a case study to examine how shrub habitat will respond to predicted future warming, and how these changes may impact habitat connectivity and the distribution of moose (Alces alces). We used a 19 year moose location dataset, a 568 km transect of field shrub sampling, and forecasted warming scenarios with regional downscaling to map current and projected shrub habitat for moose on the North Slope of Alaska. The tall‐shrub habitat for moose exhibited a dendritic spatial configuration correlated with river corridor networks and mean July temperature. Warming scenarios predict that moose habitat will more than double by 2099. Forecasted warming is predicted to increase the spatial cohesion of the habitat network that diminishes effects of fragmentation, which improves overall habitat quality and likely expands the range of moose. These findings demonstrate how climate change may increase habitat connectivity and alter the distributions of shrub herbivores in the Arctic, including creation of novel communities and ecosystems. 

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5. Winter Tick Burdens for Moose Are Positively Associated With Warmer Summers and Higher Predation Rates

   https://doi.org/10.3389/fevo.2021.758374  

   Hoy, Sarah R.; Vucetich, Leah M.; Peterson, Rolf O.; Vucetich, John A. (November 2021, Frontiers in Ecology and Evolution)

   Climate change is expected to modify host-parasite interactions which is concerning because parasites are involved in most food-web links, and parasites have important influences on the structure, productivity and stability of communities and ecosystems. However, the impact of climate change on host–parasite interactions and any cascading effects on other ecosystem processes has received relatively little empirical attention. We assessed host-parasite dynamics for moose ( Alces alces ) and winter ticks ( Dermacentor albipictus ) in Isle Royale National Park over a 19-year period. Specifically, we monitored annual tick burdens for moose (estimated from hair loss) and assessed how it covaried with several aspects of seasonal climate, and non-climatic factors, such as moose density, predation on hosts by wolves ( Canis lupus ) and wolf abundance. Summer temperatures explained half the interannual variance in tick burden with tick burden being greater following hotter summers, presumably because warmer temperatures accelerate the development of tick eggs and increase egg survival. That finding is consistent with the general expectation that warmer temperatures may promote higher parasite burdens. However, summer temperatures are warming less rapidly than other seasons across most regions of North America. Therefore, tick burdens seem to be primarily associated with an aspect of climate that is currently exhibiting a lower rate of change. Tick burdens were also positively correlated with predation rate, which could be due to moose exhibiting risk-sensitive habitat selection (in years when predation risk is high) in such a manner as to increases the encounter rate with questing tick larvae in autumn. However, that positive correlation could also arise if high parasite burdens make moose more vulnerable to predators or because of some other density-dependent process (given that predation rate and moose density are highly correlated). Overall, these results provide valuable insights about interrelationships among climate, parasites, host/prey, and predators. 

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