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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 (< 50%), adult calving (< 60%), twinning rate (< 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. [ABSTRACT FROM AUTHOR]

Eastern moose (Alces alces americana) are heavily parasitized by winter ticks (Dermacentor albipictus), the dominant cause of increased calf mortality in the northeastern US. Although much work has focused on the direct negative effects of winter tick on moose, it remains unknown whether diseases transmitted by ticks may also affect moose health or pose a risk to other species. We explored the role that moose and winter ticks play in transmission of the tick-borne bacterial pathogens, Anaplasma spp., which cause mild to severe illness in humans and domestic animals. Our objectives were to 1) estimate the prevalence of Anaplasma spp. in moose and winter ticks; 2) determine the phylogenetic placement of these strains with respect to those found in other hosts and vectors; and 3) explore risk factors of Anaplasma infection in moose. A total of 157 moose (142 calves, 15 adults) were captured in western (n=83) and northern (n=74) Maine in 2017 and 2018. We screened for Anaplasma spp. in moose whole blood samples using a genus-specific PCR assay targeting the 16S rRNA gene. Over half (54%) of the moose were infected with Anaplasma bacteria, with a greater proportion of moose harboring Anaplasma-infections in the western (67%) versus northern study areas (38%). Male moose exhibited a higher prevalence than did females (63% vs. 47%). In contrast, Anaplasma spp. prevalence in winter ticks was low (<1%). Sequencing and phylogenetic analysis revealed that the single Anaplasma strain in moose was highly divergent from the strain in winter ticks and most closely related to an uncharacterized North American cervid strain. We conclude that winter ticks are unlikely to play a significant role in Anaplasma transmission to moose; however, high infection prevalence warrants further investigation into the impacts of Anaplasma spp. infection on moose health. [ABSTRACT FROM AUTHOR]

Recent decline in New Hampshire's moose (Alces alces) population is attributed to sustained parasitism by winter ticks (Dermacentor albipictus) causing high calf mortality and reduced productivity. Location of larval winter ticks that infest moose is dictated by where adult female ticks drop from moose in April when moose preferentially forage in early regenerating forest in the northeastern United States. The primary objectives of this study were to: 1) measure and compare larval abundance in 2 types of regenerating forest (clear-cuts and partial harvest cuts), 2) measure and compare larval abundance on 2 transect types (random and high-use) within clear-cuts and partial harvests, and 3) identify the date and environmental characteristics associated with termination of larval questing. Larvae were collected on 50.5% of 589 transects; 57.5% of transects in clear-cuts and 44.3% in partial cuts. The average abundance ranged from 0.11-0.36 ticks/m2 with abundance highest (P < 0.05) in partial cuts and on high-use transects in both cut types over a 9-week period; abundance was ~2 × higher during the principal 6-week questing period prior to the first snowfall. Abundance (collection rate) was stable until the onset of < 0°C and initial snow cover (~15 cm) in late October, after which collection rose temporarily on high-use transects in partial harvests during a brief warm-up. The higher abundance of winter ticks on high-use transects indicates that random sampling underestimates tick abundance and relative risk of infestation of moose. Calculating an annual index of infestation of winter ticks on moose is theoretically possible by integrating 3 factors: the infestation of harvested moose in October, the length of the questing period, and assuming a stable collection rate during the questing period. [ABSTRACT FROM AUTHOR]

Moose naturally acquire soil fungi on their fur that are entomopathogenic to the winter tick, Dermacentor albipictus. Presumed to provide a measure of on-host tick control, it is unknown whether these soil fungi impact subsequent off-host stages of the tick. Eggs and resultant larvae originating from engorged, adult female winter ticks collected from dead calf moose (Alces alces) were used to investigate the presence and extent of fungal infection. Approximately 40% of eggs and larvae were infected, almost exclusively by the fungus Scopulariopsis brevicaulis (teleomorph Microascus brevicaulis: Microascaceae, Ascomycota). Eggs analysed on the day of oviposition and day of hatching had high frequency (40%) of S. brevicaulis, whereas the frequency in eggs harvested in utero was minimal (7%); therefore, exposure occurs pre-oviposition in the female's genital chamber, not by transovarial transmission. At hatching, larvae emerge containing S. brevicaulis indicating transstadial transmission. Artificial infection by topical application of eggs and larvae with a large inoculum of S. brevicaulis spores caused rapid dehydration, marked mortality; pathogenicity was confirmed by Koch's postulates. The high hatching success (>90%) and multi-month survival of larvae imply that S. brevicaulis is maintained as a natural pathobiont in winter ticks. [ABSTRACT FROM AUTHOR]

Certain moose (Alces alces) populations in the northeastern United States are in decline because of increasing frequency of winter tick (Dermacentor albipictus) epizootics characterized by high calf mortality and reduced productivity in the population. Previous research identified soil fungi in wallows of bull moose that are pathogenic to larval winter ticks. We analysed skin/hair samples of moose harvested in Maine, USA, to further understand this fungus–tick–moose relationship. A total of 32 keratinophilic fungi from moose fur and skins were isolated, predominately Penicillium, Cladosporium, Aspergillus, Alternaria, Trichoderma, Beauveria, and Scopulariopsis. Each displayed pathogenic activity against unfed winter tick larvae (sole infestation stage) by topical application of spore inoculums and Koch's postulates. Bulls had more entomopathogenic fungi, pathogenic fungal isolates to ticks, and infected larvae than cows and calves. We propose a disease cycle with interactions of soil fungi, moose, and on-host winter tick larvae killed by entomopathogenic soil fungi. Bull moose presumably experience enhanced exposure and protection from abundant soil fungi due to their wallowing behaviour during the breeding season that is coincidental with questing by winter tick larvae. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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]

We report that larvae ofDermacentor albipictuscan detect CO2from a dry ice source at distances up to 3.0 m and initiate increased activation, movement and questing behaviour. The maximum distance that larvae spread was ~0.5 m after 24 h, compared to <0.1 m without CO2as an excitant. In Petri dish bioassays, 2,6-dichlorophenol, methyl salicylate ando-nitrophenol acted as attractants, albeit with mixed results at 1.0 m, 2.0 m and 3.0 m, respectively. The 2,6-dichlorophenol target was the most effective, although few larvae crawled >1.0 m and CO2was required as a carrier. In Petri dish bioassays, larvae arrested into dense aggregations on eggshells collected after hatching. This arrestment was associated with the eggshell lipids cholesteryl oleate and cholesteryl palmitate, implying that cholesteryl esters act as assembly pheromones for larvae. Faster response was evident at 65% relative humidity (RH) versus 95% RH. Larvae were not arrested by tick excreta, guanine or related purines. Although larvae can be activated from long distances, in the field they remain fairly localized around the egg mass (hatching location), have limited dispersal and are more responsive in drier conditions. Given their arrestant properties, cholesteryl oleate and cholesteryl palmitate may prove useful in pheromone-assisted control methods becauseD. albipictuslarvae are the single stage of infestation to the host. [ABSTRACT FROM AUTHOR]

An isolate of the soil fungus Scopulariopsis brevicaulis was identified from the surface of female winter ticks (Dermacentor albipictus) collected from recently dead moose (Alces alces) calves in New Hampshire in the northeastern United States. It was the sole isolate, and it matched with 98% nucITS similarity (molecular systematics Blast match) to S. brevicaulis species from soil and other tick species. Inoculation of tick larvae and eggs with 108 spores/mL + 0.05% Tween (aqueous inoculum) resulted in mortality, reduced survival time, and recovery of S. brevicaulis from within tick tissues. Rapid water loss and death from dehydration were the pathogenic consequences of the fungal infection. Three entomopathogenic fungal isolates from laboratory culture (Beauveria bassiana, B. caledonica, and Metarhizium anisopliae) inoculated concurrently at the same dose, were slightly less pathogenic to eggs than larvae of winter ticks. We conclude that S. brevicaulis imposes a limitation on the freeliving stages of the winter tick population in specific environmental conditions, but commercial fungal treatments as used in local situations to control ticks, are impractical as a means of controlling winter tick density across moose habitats. [ABSTRACT FROM AUTHOR]

Moose (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. [ABSTRACT FROM AUTHOR]

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 = 7min) with long intervals between visits (median = 419min), and visits by different martens at the same trap <15 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. [ABSTRACT FROM AUTHOR]

To explore how the one-host tick Dermacentor albipictus survives off-host, we determined water balance characteristics of eggs and larvae. In contrast to eggs, larvae lost water fast, absorbed water vapour and died from a low amount of water loss. Placing mated females under near water-saturated conditions yielded larvae that absorbed and survived only at high relative humidities. We observed larvae forming clusters. Water loss rate of larvae decreased as group size increased. In response to day length, larvae lost water slower under long day than short day conditions. Larvae could switch quickly between fast water loss rate (short day) and slow water loss rate (long day) within a day, independent of the photoperiodic experience of the egg or mother. Long day exposure had no effect on water relations, incubation and survival of eggs. We conclude that eggs are modified for water conservation. Larvae survive by having a water balance maternal effect; i.e. capacity for water vapour absorption in the larva is determined by the relative humidity experienced by the mother. Larvae regulate water loss behaviourally through larval clustering and summer quiescence. Understanding these water balance attributes and effects of desiccation on egg and larval survival during summer are important to better predict the potential population impacts of winter ticks on moose. [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]

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. [ABSTRACT FROM AUTHOR]

Moose (Alces alces) play an important role in the ecological and economic resources of northern New England, a landscape dominated by commercial forests. This study measured the impact of moose browsing on forest regeneration in Wildlife Management Unit El in northeastern Vermont where moose density was considered high in the 1990-2000s. We surveyed 37 clearcuts categorized into 4 age classes (3-5, 6-10, 11-15, and 16-20 years old). The stocking rate (stems/plot) of commercial species ranged from 74-76% in the 3-5, 6-10, and 11-15 year age classes, increasing to 86% in the 16-20 year age class. The proportion of plots containing a commercial tree without severe damage was above the accepted threshold stocking level of 40-60% in all age classes. The proportion of plots containing a commercial hardwood stem declined with increasing age class; the opposite occurred with softwood stems indicating a possible shift from hardwood- to softwood-dominated stands from selective browsing pressure. Height of 11-20 year old stems was less than in New Hampshire, indicating that growth was possibly suppressed in Vermont due to higher moose density. Overall, browsing was not considered a major problem based upon stocking rates. Further study is warranted to evaluate whether compensatory growth occurs in response to reduced browsing as forests age and/or moose population density declines. [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]

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. [ABSTRACT FROM AUTHOR]

The impact of moose (Alces alces) browsing on the regeneration of commercial hard- wood and softwood tree species was evaluated in 3 regions with different moose population densities (0.26-0.83 moose/km2) in northern New Hampshire. Regeneration surveys were conducted in 4 age classes of clear-cuts (0-5, 6-10, 11-15, and 16-20 years) in June-August 2009. Stocking rate, tree height, and damage of dominant commercial stems were measured to assess regeneration and browse damage among age classes and regions. We assumed that a stocking rate of 40-60% (stems/plot) dominant commercial tree species without severe damage was an acceptable threshold of browse damage to achieve a fully stocked stand at 80 years. Mean stocking rate of all age classes was above the threshold in all regions (47-85%); the lowest stocking rates (47-52%) occurred in the 0-5 year age class but increased thereafter in all regions. The CT Lakes region (highest moose density) had more damage than both the North and White Mountain regions in the 11-15 year age class (F= 3.05; df; 6; P = 0.0002 and 0.0058, respectively). Tree heights were lower in the CT Lakes region (F = 2.30; df 6; P = 0.04). Most damage was restricted to a few isolated clear-cuts at higher elevation near moose wintering areas that were possibly shifting to conifer dominance. Regeneration of commercial tree species was not considered a regional problem at any moose density in northern New Hampshire. [ABSTRACT FROM AUTHOR]

Abundance indices suggested that the moose Alces alces population in northern New Hampshire was stable despite favourable habitat and conservative harvest. Causes and rates of mortality were unknown because moose reproduction and survival was unstudied in the region. Our study was designed to investigate the dynamics of the regional population in 2002-2005.Atotal of 92 moose (33 cows and 59 calves) were captured and fitted with radio-collars (VHF=83, GPS= 9). Parturition ranged from 8 May to 13 July (median = 19 May) with 78% of births occurring during 13-27 May. Calving rate of yearlings and adults (>2 years old) averaged 30 and 85%, respectively; twinning rate was 11%. Analysis of reproductive data from harvested cows (1988-2004) indicated that the average weight of adult cows increased but their corpora lutea count declined from ; 1.4 to 1.2/cow. Both ovulation rate and average weight of yearling cows declined about 25 and 4%, respectively. There were 39 mortalities (49% calves) with winterkill/parasite (41%), vehicle collision (26%) and hunting (18%) as the leading causes. Major sources of mortality of radio-marked cows were human-related; survival was 0.87. Annual calf survival was 0.45. Unmarked calf (0-2 months of age) survival was 0.71 with 76% of mortality in the first month of life. Radio-marked calves (∼7-12 months of age) had a survival rate of 0.67; 74% of the mortality was winterkill/parasite related. Calf mortality was concentrated (88%) in late winter-early spring. The unseasonably warm and snowless fall in 2001 probably favoured high tick transmission and increased tick loads on moose that resulted in high calf mortality (0.51) and measurable cow mortality (10%) in mild winter-spring 2002. Documentation of substantial tick-related mortality of radio-marked moose calves was unique to this study. The stability of the moose population probably reflects the variation in annual recruitment and lower fecundity of yearling cows associated with heavy infestations and epizootics of winter tick. Given that fertility, calving rate and body condition of adult cows, and summer calf survival are annually high, the population should recover from tick epizootics that periodically inhibit population growth. [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]

Moose (AIces alces) are susceptible to late winter mortality from infestation of winter ticks (Dermacentor albipictus) throughout much of North America. Calves, perhaps more so than other ages of moose, likely experience chronic, and eventually acute anemia from blood removal by adult female ticks that peaks during weeks 4 - 6 of the 8-week engorgement period. We modeled the potential metabolic impact on protein and energy balance of moose calves associated with blood loss during four levels, low to severe, of winter tick infestation. Our conservative estimates indicated that total blood loss in weeks 4 - 6, as a percent of total blood volume, ranged from 27 to 48% and 64 to 112% during moderate (30,000 ticks) and severe (70,000 ticks) infestations, respectively. The percent of the daily metabolizable energy requirement needed to replace daily blood loss during weeks 4 - 6 was 4.9- 8.2% and 11.4 - 19.2% during moderate and severe infestations, respectively. The protein deficit associated with blood loss and regeneration was the most critical metabolic impact. Daily protein loss during weeks 4 - 6 was 29 - 49% and 68 - 114% of the daily protein requirement in moderate and severe infestations, respectively. Daily protein losses of ∼ 30 to > 100% occurred for 2 continuous weeks. Energy costs associated with compensating for blood loss would likely elevate the daily energy deficit normal at end of winter, accelerate nutritional decline and weight loss, and cause increased physiological stress related to concurrent anemia. Severely infested calves are obviously susceptible to late winter mortality, and the impact of moderate infestations would be exacerbated by secondary parasitic infestations, severe winters, and poor body condition. [ABSTRACT FROM AUTHOR]

We examined behavioral response of moose to wildlife viewers and traffic stimuli at a moose viewing blind located on a roadside salt lick in northern New Hampshire during summer, 1997-1999. Feeding, fleeing, alertness, looking, grooming, and moving were measured relative to a standard viewer and a variety of stimuli associated with viewers and traffic. in general, moose were reasonably tolerant of most stimuli as moose never fled the lick> 15% of the time. Educational material likely influenced viewer behavior. Stimuli that caused a reduction in feeding and increased fleeing were loud viewers, cars stopped, and trucks passing, as well as combinations of stimuli including these factors. Viewing satisfaction and impacts can be addressed by considering these findings at moose viewing sites. [ABSTRACT FROM AUTHOR]

In northern New Hampshire, we examined the use patterns of moose visiting a roadside salt lick before (1996) and after (1997–1999) a blind was built specifically to view moose at the lick. Moose visitation patterns were monitored with trail monitors equipped with cameras placed on trails leading into the study and control salt licks. There was no difference in frequency of use and time of use at the study and control sites in any year. Nocturnal use was higher than diurnal use; use was greatest at 2200–2400 and 0400–0600 hours at both sites. Reduced use of the trail closest to the blind indicated that placement of the blind probably altered access patterns of certain moose. A trend in 1998–1999 toward more visits during early morning than peak afternoon viewing time indicated that assessment of viewing opportunity warrants further study. [ABSTRACT FROM AUTHOR]

• Agent-based models, parameterized using existing studies on moose (Alces alces) and winter ticks (Dermacentor albipictus), can be used to simulate populational trends similar to those observed in the field and are therefore a promising tool for managing moose populations in northern New England against epizootic events. • Highly concentrated optimal habitat is an important driver of winter tick epizootics. • Winter tick infestations are positively correlated with moose density. • At densities ≤ 0.40 moose/km2, weather conditions including summer drought and late onset of snow become less important in predicting epizootics than at densities > 0.40 moose/km2. • The number of winter ticks aggregating in a cluster is an important variable to consider when modeling winter tick epizootics and warrants focus in field studies. North American moose (Alces alces) populations along the southern extent of their range have been experiencing high levels of calf mortality in recent years. In New England, this phenomenon has been linked to extensive blood loss resulting from extreme winter tick (Dermacentor albipictus) parasitism. Moose are symbolic of the region and generate income through tourism and the auction of hunting permits; thus, successive years of greater than 50% calf mortality (epizootics) are of concern to wildlife managers and others. It is hypothesized that high localized moose density coupled with climate change are the driving forces behind moose-winter tick epizootics; however, the impact that variable combinations of these and other factors have on the occurrence and magnitude of epizootics has not been previously simulated. We, therefore, developed and implemented a spatially explicit agent-based model with two model environments, each representative of a distinct location within an ongoing field study site in northern New Hampshire that differed in the proportional availability of optimal moose habitat. Three experiments were devised to test the sensitivity of the outcome variables, calf infestation level and calf mortality, to 1) winter tick abundance, 2) winter tick aggregation, and 3) moose density, for the length of the winter tick questing period. Each experiment was conducted in both model environments. This model generated similar mortality levels to those measured in the field study under representative moose density and weather conditions. Additionally, the modeled moose agents and the radio-collared moose in the field reflect comparable habitat usage. While the infestation levels reported by calf agents are considered conservative, we believe that future versions of this model, parameterized with more accurate estimates of winter tick abundance and moose density, may be an effective tool for managing moose against winter tick parasitism. [ABSTRACT FROM AUTHOR]

A foreword to "Alces: A Journal Devoted to the Biology and Management of Moose" is presented.

Acquiring accurate and precise population parameters is fundamental to the ecological understanding and management and conservation of moose (Alces alces). Moose density is challenging to measure and often estimated using winter aerial surveys; however, numerous alternative approaches exist including harvest analysis, public observation, unpiloted aerial system (UAS) surveys, and camera trapping. Given recent developments in a number of field and analytical techniques, there is value in reviewing and synthesizing the strengths and limitations of monitoring methods to best evaluate their respective tradeoffs in management scenarios. We reviewed 89 studies that included 131 estimates or indices of moose density. As expected, aerial surveys were the most common method of obtaining a moose density estimate (58%) followed by use of public data (e.g., harvest records = 27%); more recent studies employed novel methods including UAS. Most estimates (64%) failed to account for imperfect detection of moose (i.e., "sightability") and this tendency has not improved over time. Density estimates ranged from <0.1 to 10.6 moose/km² (average = 0.7) and population precision, as measured by the 90% confidence interval, ranged from 6.5 to 120.0% of the density estimate (average = 37.4%). Correlations among estimates obtained for the same populations varied widely, with R² values ranging from 0.02 to 0.99 (average = 0.58). Our review indicates that: 1) methods to estimate moose density have been dominated by aerial surveys but are diversifying, 2) precision of density estimates has been highly variable and on average lower than broadly accepted target benchmarks, and 3) many methods did not account for sightability and presumably underestimated moose density. We reflect on these trends and discuss how emerging methods, including camera trapping, UAS surveys, and integrated population modeling (IPM) can complement and improve traditional approaches. We suggest that no single "best" method exists, but rather the best method is one that accounts for sightability bias and yields target precision at reasonable cost, which vary by jurisdiction and goal. [ABSTRACT FROM AUTHOR]