Moose Population Research Articles

Reproductive success and failure: the role of winter body mass in reproductive allocation in Norwegian moose

A life history strategy that favours somatic growth over reproduction is well known for long-lived iteroparous species, especially in unpredictable environments. Risk-sensitive female reproductive allocation can be achieved by a reduced reproductive effort at conception, or the subsequent adjustment of investment during gestation or lactation in response to unexpected environmental conditions or resource availability. We investigated the relative importance of reduced investment at conception compared with later in the reproductive cycle (i.e. prenatal, perinatal or neonatal mortality) in explaining reproductive failure in two high-density moose (Alces alces) populations in southern Norway. We followed 65 multiparous, global positioning system (GPS)-collared females throughout the reproductive cycle and focused on the role of maternal nutrition during gestation in determining reproductive success using a quasi-experimental approach to manipulate winter forage availability. Pregnancy rates in early winter were normal (≥0.8) in all years while spring calving rates ranged from 0.4 to 0.83, with prenatal mortality accounting for most of the difference. Further losses over summer reduced autumn recruitment rates to 0.23-0.69, despite negligible predation. Over-winter mass loss explained variation in both spring calving and autumn recruitment success better than absolute body mass in early or late winter. Although pregnancy was related to body mass in early winter, overall reproductive success was unrelated to pre-winter body condition. We therefore concluded that reproductive success was limited by winter nutritional conditions. However, we could not determine whether the observed reproductive allocation adjustment was a bet-hedging strategy to maximise reproduction without compromising survival or whether females were simply unable to invest more resources in their offspring.

Factors affecting deer ked (Lipoptena cervi) prevalence and infestation intensity in moose (Alces alces) in Norway

BackgroundThe deer ked (Lipoptena cervi), a hematophagous ectoparasite of Cervids, is currently spreading in Scandinavia. In Norway, keds are now invading the south-eastern part of the country and the abundant and widely distributed moose (Alces alces) is the definitive host. However, key factors for ked abundance are poorly elucidated. The objectives of our study were to (i) determine deer ked infestation prevalence and intensity on moose and (ii) evaluate if habitat characteristics and moose population density are determinants of deer ked abundance on moose.MethodsIn order to identify key factors for deer ked abundance, a total of 350 skin samples from the neck of hunted moose were examined and deer keds counted. Infestation intensity was analyzed in relation to moose age and sex, moose population density and landscape characteristics surrounding the killing site.ResultsDeer ked infestation prevalence was 100%, but infestation intensity varied from 0.001 to 1.405 keds/cm2. Ked intensity was highest in male yearlings (~1.5 years) and positively associated with longitude and Scots pine (Pinus sylvestris) dominated habitat and negatively associated with bogs and latitude. Moose population density during autumn showed a tendency to be positively associated, while altitude tended to be negatively associated with ked intensity.ConclusionsDeer keds exploit the whole moose population within our study area, but are most prevalent in areas dominated by Scots pine. This is probably a reflection of Scots pine being the preferred winter browse for moose in areas with highest moose densities in winter. Ked intensity decreases towards the northwest and partly with increasing altitude, probably explained by the direction of dispersal and reduced temperature, respectively. Abundant deer ked harm humans and domestic animals. Moose management authorities should therefore be aware of the close relationship between moose, deer ked and habitat, using the knowledge as a management tool for locally regulating the ked burden.

Simulated responses of moose populations to browsing‐induced changes in plant architecture and forage production

We and others have previously shown that browsing by large mammalian herbivores can alter the fractal dimension and other architectural properties of plant crowns. Using data from an experiment in northern Sweden which manipulated moose population densities from 0 to 50 moose per 1000 ha and measured architectural responses of birch, Betula pendula and B. pubescens, and Scots pine, Pinus sylvestris, we constructed a simulation model to examine how these changes in plant crown architecture affect moose population dynamics. Architectural changes in birch tree crowns caused forage availability to increase from low to moderate moose population densities, then decline at higher densities. In contrast, forage availability of pine decreased monotonically with increasing moose population density. The model, which incorporated equations fitted to these experimental results, predicted realistic moose population densities for northern Sweden. More importantly, the model also predicted that the quadratic responses of birch crowns to moose browsing results in moose population oscillations on high productivity sites because the moose population density overshoots the maximum birch forage availability then declines. Changes in the geometry of plant canopies caused by mammalian browsers and soil fertility may feed back on the population dynamics of the browsers themselves and even result in complex dynamics such as population oscillations.

Climate Change, Moose and Humans in Northern Sweden 4000 cal. yr BP

Major cultural and environmental changes took place in the interior of Northern Sweden, beginning about c. 4200 cal. yr BP (or 2200 cal. BC). We present a causal, plausible, relationship linking climate change, a key resource and human culture. Moose (Alces alces) disappeared relatively fast from the human culture evidenced by a rapid decrease in usage and symbolism. Given the climatic data reconstructed at hand, a drastic change towards colder and wetter conditions seems to have happened 4200–3600 BP, which affected moose population numbers and composition significantly. After analyzing multiple data sources we suggest that moose had become very rare due to climate change and that many of the northern Fennoscandian hunting cultures had no choice but to change their subsistence pattern and, perhaps, change their general way of life, as a response to the altered situation. Linking the past to the present we speculate whether climate change as the primary driver, together with human harvest as the secondary, can result in fast extinction of a key species.

Plant toxins and trophic cascades alter fire regime and succession on a boreal forest landscape

Two models were integrated in order to study the effect of plant toxicity and a trophic cascade on forest succession and fire patterns across a boreal landscape in central Alaska. One of the models, ALFRESCO, is a cellular automata model that stochastically simulates transitions from spruce dominated 1km2 spatial cells to deciduous woody vegetation based on stochastic fires, and from deciduous woody vegetation to spruce based on age of the cell with some stochastic variation. The other model, the ‘toxin-dependent functional response’ model (TDFRM) simulates woody vegetation types with different levels of toxicity, an herbivore browser (moose) that can forage selectively on these types, and a carnivore (wolf) that preys on the herbivore. Here we replace the simple succession rules in each ALFRESCO cell by plant–herbivore–carnivore dynamics from TDFRM. The central hypothesis tested in the integrated model is that the herbivore, by feeding selectively on low-toxicity deciduous woody vegetation, speeds succession towards high-toxicity evergreens, like spruce. Wolves, by keeping moose populations down, can help slow the succession. Our results confirmed this hypothesis for the model calibrated to the Tanana floodplain of Alaska. We used the model to estimate the effects of different levels of wolf control. Simulations indicated that management reductions in wolf densities could reduce the mean time to transition from deciduous to spruce by more than 15 years, thereby increasing landscape flammability. The integrated model can be useful in estimating ecosystem impacts of wolf control and moose harvesting in central Alaska.

Coping in a human-dominated landscape: trade-off between foraging and keeping away from roads by moose (Alces alces)

Roads fragment moose habitat and cause increased mortality through moose–vehicle collisions. Previous studies have found that moose avoid areas near roads. In late winter, when moose face depleting food resources elsewhere, moose may be more prone to use areas near roads for foraging. However, this presumed trade-off between foraging and keeping away from roads has not previously been investigated. We sampled positions from global positioning system-collared moose in late winter from a high-density moose population in Southern Norway that is heavily influenced by human infrastructure. We combined data on moose positions with detailed field surveys of food abundance at sites that were, respectively, intensively used or sparsely used by moose. The probability that a site was intensively used increased with increasing abundance of high-quality browse and also with increasing distance to the nearest road. This indicates that moose trade-off foraging against keeping away from roads. We also found that spatio-temporal movements in relation to roads were influenced by variation in perceived human-derived risk; moose moved closer to smaller roads (low traffic volume) than to major roads (higher traffic volume) and closer to roads at night than at day. Males moved closer to roads than females. In conclusion, moose clearly exhibited behavioural adaptations to cope with roads and traffic in the study area. Because availability of high-quality forage substantially influenced habitat use, it may be an option to establish artificial feeding sites during winter to keep moose away from the roads.

Historical-ecological evaluation of the long-term distribution of woodland caribou and moose in central British Columbia

Throughout the 1800s and the 1900s, woodland caribou disappeared from much of the central and southern portions of British Columbia, Canada. Conversely, moose populations expanded during the 1900s and rapidly colonized forested areas formerly occupied by caribou. Although the general trend in range recession and expansion is documented, the processes, timing, and spatial extent of overlap between these two ungulates are uncertain. Such details have implications for our understanding of the ecology of these species and the conservation of woodland caribou. Using historical-ecological methods, we documented the distribution and abundance of caribou and moose over a 150-year period. Also, we evaluated three general sources of evidence for documenting long-term changes in the distribution of hunted or trapped fauna: (1) semi-structured interviews with Aboriginal and non-aboriginal residents; (2) journals of the Hudson's Bay Company (HBC); and (3) primary written sources. The findings of this study suggested that caribou were relatively wide-spread throughout the study area until the late 1800s when their distribution began to decline. The first recorded sighting of moose in the study area was 1832, although consensus among sources suggested that moose expanded into the area at the end of the 1800s becoming abundant in the 1920s and 1930s. Proposed causes of decline of caribou included climatic change during the 1800s and habitat loss, hunting, and altered predator-prey dynamics through the early 1900s. Our analysis of three sources of historical information and knowledge confirmed the value of Local and Traditional Ecological Knowledge in documenting and explaining long-term historical distribution of hunted species. Alternatively, HBC journals and other written sources provided good temporal specificity, but few recorded locations of caribou or moose. Documenting changes in the long-term distribution of both species can enlighten conservation planning for woodland caribou.

Moose (Alces alces) calf survival rates in the presence of wolves (Canis lupus) in southeast Norway

Wolves (Canis lupus) are recolonizing Scandinavia and becoming a new limiting factor that should be taken into account in the management of moose (Alces alces). However, there is a lack of empirical estimates of moose survival after wolf recolonization. We investigated the effects of wolf abundance, moose litter size (single/twin calves), and climatic factors on annual and seasonal calf survival rates in a moose population in southeast Norway. We used data that were obtained over 7 years by radio-tracking and regular visual observations of 68 moose cows to determine the presence or absence of calves at heel. Annual and winter calf survival rates were 20–40 percentage points lower in the wolf territory compared with previous estimates of moose calf survival in similar areas that lacked wolves. Cause-specific studies of mortality would further enhance our ability to determine the relative role of various limiting factors. Our study suggests that moose managers should regulate quotas to buffer the lower survival rates after wolf recolonization.

Managing moose harvests by the seat of your pants

Moose populations are managed for sustainable yield balanced against costs caused by damage to forestry or agriculture and collisions with vehicles. Optimal harvests can be calculated based on a structured population model driven by data on abundance and the composition of bulls, cows, and calves obtained by aerial-survey monitoring during winter. Quotas are established by the respective government agency and licenses are issued to hunters to harvest an animal of specified age or sex during the following autumn. Because the cost of aerial monitoring is high, we use a Management Strategy Evaluation to evaluate the costs and benefits of periodic aerial surveys in the context of moose management. Our on-the-fly “seat of your pants” alternative to independent monitoring is management based solely on the kill of moose by hunters, which is usually sufficient to alert the manager to declines in moose abundance that warrant adjustments to harvest strategies. Harvests are relatively cheap to monitor; therefore, data can be obtained each year facilitating annual adjustments to quotas. Other sources of “cheap” monitoring data such as records of the number of moose seen by hunters while hunting also might be obtained, and may provide further useful insight into population abundance, structure and health. Because conservation dollars are usually limited, the high cost of aerial surveys is difficult to justify when alternative methods exist.

Assessment of the status and viability of a population of moose (Alces alces) at its southern range limit in Ontario

Factors affecting the distribution and abundance of animals are of substantial interest, and across most of their southern range, populations of moose ( Alces alces (L., 1758)) are declining, presumably because of climate change. Conditions favouring moose population decline versus numerical increase in select areas of the range are not well understood. During 2006–2009, we tested the hypothesis that moose in southern Ontario formed a viable population near the species’ southern range limit, despite occurrence of climate patterns apparently deleterious for population growth. Our study upheld each of our predictions: (i) high pregnancy rate (83.0%) and annual female survival rate (0.899 (0.859, 0.941; 95% CI)), indicating that the population was increasing (λ = 1.16); (ii) female moose having blood-based condition indices within normal range, despite larger than expected home-range size; and (iii) levels of genetic differentiation indicating that the population was part of a larger metapopulation of moose in the region. We surmise that moose in southern Ontario currently are not subject to the prevalent continental decline, likely owing to favourable site-specific climatic conditions. Future research should elaborate on why select southern moose populations are increasing and whether they will ultimately succumb to die off as effects of climate change become increasingly pronounced.

The complimentary role of genetic and ecological data in understanding population structure: a case study using moose (Alces alces)

Landscape features can influence animal move- ments and gene flow, so rigorous analysis of population structure should include both levels of analysis. We conducted individual-based landscape genetic analysis, using data from eight microsatellite loci, on adult female moose (Alces alces; n=92) from two areas in southern Ontario, and also monitored movements of a subsample of animals (n=38) to gauge complementarity of the data sources (genetic and telemetry data) in understanding patterns of population structure. Genetic data indicated that female moose constituted a single panmictic population encompassing both areas, with no evidence of isolation by Euclidean (Mantel test p>0.38) or least-cost (Mantel test p>0.19) distances, even when such distances were calcu- lated from costs extracted from resource selection functions of the radio-collared individuals. In contrast, throughout the 2.5-year study radio-telemetry data failed to reveal large- scale movement of female moose. In fact, although moose tended to occupy home ranges in a wide range of sizes, their locations were largely fixed at a larger spatial scale encompassing both study areas. This finding implies that radio-telemetry data alone would not have revealed the extent of connectivity between moose populations, whereas least-cost genetic measures in the absence of telemetry data would not have shown the localised movements of adult females. Our contrasting results highlight the importance of multiple sources of information when assessing population connectivity of large mammals.

Chemical and structural composition of Atlantic Canadian moose (Alces alces) incisors with patterns of high breakage

Analysis of mammalian teeth can provide information regarding local environmental conditions. For example, a high incidence of breakage and wear within a population may indicate poor food quality. Individuals consuming a diet causing high mechanical stress on their teeth, and/or lacking the appropriate minerals for proper development, could experience degradation of tooth condition. Previously, we documented a high rate of incisor tooth breakage, with age, in two genetically distinct moose populations in Atlantic Canada. In this study, multi-element (11B, 63Cu, 64Zn, 75As, 85Rb, 88Sr, 111Cd, 118Sn, 137Ba, 208Pb, 232Th, and 238U) analyses using laser ablation ICP-MS were performed on moose incisors from multiple North American regions. The purpose was to determine whether the elemental composition of moose incisors varies among regions, and whether that variation is related to tooth degradation among Atlantic Canadian populations. A principal components analysis revealed that nearly 50% of the elemental variation in the inner enamel matrix of moose teeth was explained by three groupings of elements. The element groupings revealed differences among geographic regions, but did not explain the variation between incisors that were broken and those that were not. Regression models indicate that the elemental group which includes Cu, Pb, and Zn is related to decreases in incisal integrity. It is likely that other environmental factors contribute to the occurrence of increased incisor breakage in affected populations. The relationship between food resource quantity and quality, as a function of moose density, is hypothesized to explain loss of tooth integrity.

Effects of climate change on moose populations: Exploring the response horizon through biometric and systems models

Interest in the response of moose to climate change has increased because of the potential role they play in the conservation of woodland caribou, and threatened loss to recreational and economic opportunities. The objective of this study is to develop a plausible, parsimonious, systems-level model of moose population dynamics that will be useful in exploring the response of moose populations to climate projections. The study begins with a statistical model of moose carrying capacity, which is then integrated into a systems-level model that predicts moose density based on explicit causal factors. Scenario analysis was conducted using a variety of assumptions concerning biotic and abiotic interactions, and under the A2 climate scenario all model scenarios predict a decline of moose density at the southern limits of the Ontario distribution and an increase at the northern extents. Predicted declines are a result of lower carrying capacity and higher heat stress, parasite loads and wolf predation. Given the sensitivity of the model to density-dependent factors, the indirect effect of parasites on decreased recruitment may have greater impact on moose than the direct effect of increased death rate. Results indicate that conservation planning for woodland caribou populations should account for possible increases in moose and wolf populations.

Retrospective evaluation and modern state of the moose (Alces alces L.) population in West Siberia: Ecological and molecular-genetic aspects

Based on the analysis of materials collected for many years the dynamics of the moose’s habitat and population numbers in West Siberia is described. For the southeast of the West Siberian part of the habitat the cohabitation of mooses with the haplotypes of both European (A. a. alces L.) and East Siberian (A. a. pfizenmayeri Zukowski) subspecies is demonstrated on the basis of investigation of the structure of the mtDNA D-loop hypervariable domain. High nucleotide (p) and haplotypic (H) diversity substantially exceeding corresponding indices for the moose in the European part of Russia and the Urals has been revealed.

Effects of predator treatments, individual traits, and environment on moose survival in Alaska

AbstractWe studied moose (Alces alces) survival, physical condition, and abundance in a 3‐predator system in western Interior Alaska, USA, during 2001–2007. Our objective was to quantify the effects of predator treatments on moose population dynamics by investigating changes in survival while evaluating the contribution of potentially confounding covariates. In May 2003 and 2004, we reduced black bear (Ursus americanus) and brown bear (U. arctos) numbers by translocating bears ≥240 km from the study area. Aircraft‐assisted take reduced wolf (Canis lupus) numbers markedly in the study area during 2004–2007. We estimated black bears were reduced by approximately 96% by June 2004 and recovered to within 27% of untreated numbers by May 2007. Brown bears were reduced approximately 50% by June 2004. Late‐winter wolf numbers were reduced by 75% by 2005 and likely remained at these levels through 2007. In addition to predator treatments, moose hunting closures during 2004–2007 reduced harvests of male moose by 60% in the study area. Predator treatments resulted in increased calf survival rates during summer (primarily from reduced black bear predation) and autumn (primarily from reduced wolf predation). Predator treatments had little influence on survival of moose calves during winter; instead, calf survival was influenced by snow depth and possibly temperature. Increased survival of moose calves during summer and autumn combined with relatively constant winter survival in most years led to a corresponding increase in annual survival of calves following predator treatments. Nonpredation mortalities of calves increased following predator treatments; however, this increase provided little compensation to the decrease in predation mortalities resulting from treatments. Thus, predator‐induced calf mortality was primarily additive. Summer survival of moose calves was positively related to calf mass (β > 0.07, SE = 0.073) during treated years and lower (β = −0.82, SE = 0.247) for twins than singletons during all years. Following predator treatments, survival of yearling moose increased 8.7% for females and 21.4% for males during summer and 2.2% for females and 15.6% for males during autumn. Annual survival of adult (≥2 yr old) female moose also increased in treated years and was negatively (β = −0.21, SE = 0.078) related to age. Moose density increased 45%, from 0.38 moose/km2 in 2001 to 0.55 moose/km2 in 2007, which resulted from annual increases in overall survival of moose, not increases in reproductive rates. Indices of nutritional status remained constant throughout our study despite increased moose density. This information can be used by wildlife managers and policymakers to better understand the outcomes of predator treatments in Alaska and similar environments. © 2011 The Wildlife Society.

Patterns and causes of demographic variation in a harvested moose population: evidence for the effects of climate and density-dependent drivers

1. Better understanding of the mechanisms affecting demographic variation in ungulate populations is needed to support sustainable management of harvested populations. While studies of moose Alces alces L. populations have previously explored temporal variation in demographic processes, managers responsible for populations that span large heterogeneous landscapes would benefit from an understanding of how demography varies across biogeographical gradients in climate and other population drivers. Evidence of thresholds in population response to manageable and un-manageable drivers could aid resource managers in identifying limits to the magnitude of sustainable change. 2. Generalized additive models (GAMs) were used to evaluate the relative importance of population density, habitat abundance, summer and winter climatic conditions, primary production, and harvest intensity in explaining spatial variation in moose vital rates in Ontario, Canada. Tree regression was used to test for thresholds in the magnitudes of environmental predictor variables that significantly affected population vital rates. 3. Moose population growth rate was negatively related to moose density and positively related to the abundance of mixed deciduous habitat abundant in forage. Calf recruitment was negatively related to a later start of the growing season and calf harvest. The ratio of bulls to cows was related to male harvest and hunter access, and thresholds were evident in predictor variables for all vital rate models. 4. Findings indicate that the contributions of density-dependent and independent factors can vary depending on the scale of population process. The importance of density dependence and habitat supply to low-density ungulate populations was evident, and management strategies for ungulates may be improved by explicitly linking forest management and harvest. Findings emphasize the importance of considering summer climatic influences to ungulate populations, as recruitment in moose was more sensitive to the timing of vegetation green-up than winter severity. The efficacy of management decisions for harvested ungulates may require regional shifts in targets where populations span bioclimatic gradients. The use of GAMs in combination with recursive partitioning was demonstrated to be an informative analytical framework that captured nonlinear relationships common in natural processes and thresholds that are relevant to population management in diverse systems.

New population models help explain declines in the globally rare boreal felt lichen Erioderma pedicellatum in Newfoundland

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials ESR 13:181-189 (2011) - DOI: https://doi.org/10.3354/esr00326 New population models help explain declines in the globally rare boreal felt lichen Erioderma pedicellatum in Newfoundland R. Ian Goudie1,*, Christoph Scheidegger2, Claudia Hanel3, Anne Munier4, Eugene Conway5 1LGL Limited Environmental Research Associates, 388 Kenmount Road, St. John’s, Newfoundland and Labrador A1B 4A5, Canada 2Swiss Federal Institute for Forest, Snow and Landscape Research, WSL Zürcherstr. 111, 8903 Birmensdorf, Switzerland 3Department of Environment and Conservation, Endangered Species Branch, 117 Riverside Drive, PO Box 2007, Corner Brook, Newfoundland and Labrador A2H 7S1, Canada 4Centre for Non Timber Resources, Royal Roads University, 2005 Sooke Rd, Victoria, British Columbia V9B5Y2, Canada 5Newfoundland Lichen Education and Research Group, Box 16, Conception Harbour, Newfoundland and Labrador A0A1Z0, Canada *Email: igoudie@lgl.com ABSTRACT: A preliminary population model was developed for the boreal felt lichen Erioderma pedicellatum (Hue) P. M. Jørg. in Newfoundland using life stage data collected in eastern and south-central Newfoundland, Canada. This Critically Endangered epiphytic lichen displayed a life history strategy with high adult survival and low recruitment. Deterministic models in 6 mo to 1 yr intervals were generated, yielding similar results to the overall mean values for the 4 yr of study in eastern Newfoundland. The populations of E. pedicellatum in Newfoundland are predicted by our models to be unsustainable because of adult mortality, and we attribute this problem to a decline in the forests of balsam fir Abies balsamea (Mill) that predominantly support this lichen. In eastern Newfoundland, thalli are located almost entirely on mature to over-mature balsam fir, and there is little regeneration because of heavy browsing by the introduced moose Alces alces population. The current and projected predictors indicate that habitat effects may be important in predicting future population size. An assessment of the stable stage distribution indicated that the current population has more juveniles and fewer apothecia-bearing thalli than projected, meaning the current population likely generated from a different set of survival and recruitment rates. The projected annual population growth rates calculated for 4 yr indicated that populations are declining (λ < 1.0, mean decline ± SD = –0.175 ± 0.079). The elasticity values support the fact that the population growth rates are most sensitive to changes in the survival of necrotic (apothecia-bearing) cohorts. We suggest that conservation is best focused on the inventory and protection of old-growth forests important to this species, the reduction of the introduced moose population and the use of herbivore exclosures in specific core population areas. KEY WORDS: Demography · Population model · Boreal felt lichen · Stable stage distribution · Elasticity analysis · Old-growth forests · Dispersal · Forest landscapes Full text in pdf format Supplementary material PreviousNextCite this article as: Goudie RI, Scheidegger C, Hanel C, Munier A, Conway E (2011) New population models help explain declines in the globally rare boreal felt lichen Erioderma pedicellatum in Newfoundland. Endang Species Res 13:181-189. https://doi.org/10.3354/esr00326 Export citation Mail this link - Contents Mailing Lists - RSS Facebook - Tweet - linkedIn Cited by Published in ESR Vol. 13, No. 3. Online publication date: March 09, 2011 Print ISSN: 1863-5407; Online ISSN: 1613-4796 Copyright © 2011 Inter-Research.

Browse biomass removal and nutritional condition of moose Alces alces

AbstractWe present methodology for assessing browse removal to help evaluate resource limitation among moose Alces alces populations in large, potentially remote areas of boreal forest. During 2000‐2007, we compared proportional removal (ratio of browse consumption to browse production) in eight areas of Interior Alaska, USA, with multi‐year twinning rates of the respective moose populations. Several prior studies concluded that twinning rate provided an index of the nutritional condition of moose. We theorized that a plant‐based sampling of proportional use of browse by moose in late winter would inversely correlate with the nutritional condition of moose. We sampled willow Salix spp., quaking aspen Populus tremuloides, balsam poplar P. balsamifera and Alaska paper birch Betula neoalaskana, i.e. plants with current annual growth (CAG) between 0.5 and 3.0 m above ground. We estimated the biomass of CAG and biomass removed by moose based on bite diameters and diameter‐mass regressions specific to each browse species. Mean browse removal by moose varied among study areas from 9 to 43% of CAG. Moose twinning rate (range: 7‐64%) was inversely correlated with proportional browse removal by moose (Spearman's rho = −0.863, P &lt; 0.005). Proportional browse removal appeared useful in linking foraging ecology and population dynamics of moose in Alaska, and the technique may be used to quantify resource limitation in moose populations inhabiting boreal forest in a broader geographic region.

The Isle Royale Wolf–Moose Project (1958-present) and the Wonder of Long-Term Ecological Research

Introduction In the dead of a northwoods winter, sometime in the late 1940s, wolves crossed the roughly 15 miles of iced-over waters separating Thunder Bay, Ontario from the shores of Isle Royale (ISRO), a federally designated wilderness island and US National Park of 544 km in Northwestern Lake Superior (Figure 1). This was fortuitous. Just prior to this crossing, managers and wildlife ecologists had been discussing plans to use ISRO as a sanctuary for the heavily persecuted grey wolf population. The introduction of wolves was, moreover, seen as a possible way to control the booming and busting moose population that had swam to the island some 50 years previously.

The influences of wolf predation, habitat loss, and human activity on caribou and moose in the Alberta oil sands

Woodland caribou (Rangifer tarandus caribou) and moose (Alces alces) populations in the Alberta oil sands region of western Canada are influenced by wolf (Canis lupus) predation, habitat degradation and loss, and anthropogenic activities. Trained domestic dogs were used to locate scat from caribou, moose, and wolves during winter surges in petroleum development. Evidence obtained from collected scat was then used to estimate resource selection, measure physiological stress, and provide individual genetic identification for precise mark–recapture abundance estimates of caribou, moose, and wolves. Strong impacts of human activity were indicated by changes in resource selection and in stress and nutrition hormone levels as human‐use measures were added to base resource selection models (including ecological variables, provincial highways, and pre‐existing linear features with no human activity) for caribou. Wolf predation and resource selection so heavily targeted deer (Odocoileus virginiana or O hemionus) that wolves appeared drawn away from prime caribou habitat. None of the three examined species showed a significant population change over 4 years. However, caribou population estimates were more than double those of previous approximations for this area. Our findings suggest that modifying landscape‐level human‐use patterns may be more effective at managing this ecosystem than intentional removal of wolves.