Search

High calf mortality attributed to winter tick (Dermacentor albipictus) parasitism occurs in moose (Alces alces) populations along their southern range in the northeastern United States. We analyzed habitat use of cow and calf moose during the critical drop-off and questing periods in the winter tick life cycle to determine a potential relationship between tick density and habitat. We measured habitat use using geospatial analyses of locational data from > 200 radio-marked animals at 3 sites in New Hampshire and Maine. Moose selected for optimal habitat, defined as 4-16 year-old forest openings, regardless of season or site; this was the only land cover type used more than available (1.1-2.1X availability in home range, 1.2-3.1X availability in core range). Further, the proportional availability of optimal habitat within overlapping portions of seasonal home and core ranges exceeded the absolute proportion of optimal habitat within any one range. Temporal use of optimal habitat, which is available in relatively low proportion (15-20%) across the landscape, likely exceeds the geospatial estimates of use because moose spend 30-40% of daily activity foraging. We conclude that disproportionally abundant densities of winter ticks exist in this preferred cover type because of its selective use during the drop-off and questing periods of winter ticks. [ABSTRACT FROM AUTHOR]

Winter habitat use by moose (Alces alces) is typically comprised of regenerating forest and softwood cover in the northeastern United States, and globally, high winter densities are of concern relative to forest damage. Habitat variables associated with winter locations of moose collected during aerial surveys in Maine in 2011 and 2012 were compared to available habitat at multiple landscape scales. Mixed forest was the most used land cover type at both the location and 5 ha scales (35.1% and 31.3%, respectively). Although regenerating forest habitat was used only in proportion to availability, the proximity to recent clearcuts, light partial cuts, and heavy partial cuts was an important predictor of moose location. The used proportion of coarse habitat variables (i.e., mature and regenerating forest) were similar to those available in each aerial survey block, indicating that heterogeneous and productive moose habitat is widely available across the commercial forest landscape of northern Maine. Moose locations derived from aerial surveys can provide insight about spatial distribution and habitat use across the landscape, identify local density in areas where forest regeneration is of concern, and monitor population responses to commercial forest management practices. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Habitat use by parturient moose (Alces alces) may have important implications for calf survival and subsequently influence population dynamics. Because neonatal habitat may be limiting or specialized and little descriptive information exists in the northeastern United States, this study was conducted to measure the physical and vegetative characteristics associated with neonatal habitat of 30 maternal moose. There was no difference (P > 0.10 for each parameter) in 22 of 23 physical and vegetative parameters measured at neonatal (n = 30) and random sites (n = 30). However, neonatal sites were about 2X farther (P = 0.032) than random sites from cut/regeneration habitat where no neonatal site occurred. Most neonatal sites (> 63%) were located in pole or saw timber stands comprised of mixed or coniferous habitat (> 75%); conifers were the dominant canopy species at 67% of neonatal sites. Characteristics related to forage availability suggest that forage resources were probably not influential in location of neonatal habitat. Mature, mixed, and coniferous habitats may provide microhabitat that helps conceal neonates from potential predators such as black bears (Ursus americana), particularly in the absence of islands and open water that are believed to mitigate predation. [ABSTRACT FROM AUTHOR]

The New Hampshire Fish and Game Department and the University of New Hampshire initiated research in northern New Hampshire to better understand population dynamics and seasonal habitat use of a moose population that has apparently stabilized, despite optimal habitat and modest harvest levels. In total, 94 moose were captured by helicopter (81 net-gunned and 13 tranquilized) in December 2001–2003 and 2 were darted at salt-licks in July of 2002. Capture mortality attributed to myopathy and injury was 4%. In comparison to measured reproduction during capture (63 and 100%), our ability to measure pregnancy by direct observations (69 and 100%) was validated in 2002-2003. Production was 0.82 and 0.85 calves per adult cow; rate of twinning was 20 and 10%. Calf mortality 2 months post-partum was similar (26 and 27%) each year. Annual mortality of adult/yearling moose was 27 and 12%. Hunting and vehicle collision mortality was 4 (all adult cows) and 6% (all calves but 1) each year. High annual winter calf mortality (38–43%) in late March and early April was associated with the combined effects of malnutrition and winter tick/lung nematodes. Winter home range size was not restricted, and composition of available habitat was similar across seasons although overlap was minimal between seasons. Consideration of habitat and population dynamics data suggests that both density dependent and independent factors could be influencing the study population. [ABSTRACT FROM AUTHOR]