When does weather synchronize life-history traits? Spatiotemporal patterns in juvenile body mass of two ungulates.

Theory predicts that animal populations will be synchronized over large distances by weather and climatic conditions with high spatial synchrony. However, local variation in population responses to weather, and low synchrony in key weather variables or in other ecological processes may reduce the population synchrony. We investigated to what extent temperature and precipitation during different periods of the year synchronized juvenile body mass of moose and reindeer in Norway. We expected high synchronizing effect of weather variables with a high and consistent explanatory power on body mass dynamics across populations, and a weaker synchronizing effect of weather variables whose effect on body mass varied among populations. Juvenile body mass in both species was related to temperature and precipitation during several periods of the year. Temperature had the strongest explanatory power in both species, with a similar effect across all populations. There was higher spatial synchrony in temperature compared to precipitation, and accordingly temperature had the strongest synchronizing effect on juvenile body mass. Moreover, periods with strong explanatory power had stronger synchronizing effect on juvenile body mass in both species. However, weather variables with large variation in the effects on body mass among populations had weak synchronizing effect. The results confirm that weather has a large impact on the spatial structure of population properties but also that spatial heterogeneity, for instance, in environmental change or population density may affect how and to what extent populations are synchronized.

Opposing fitness consequences of habitat use in a harvested moose population.

Landscape changes are happening at an unprecedented pace, and together with high levels of wildlife harvesting humans have a large effect on wildlife populations. A thorough knowledge of their combined influence on individual fitness is important to understand factors affecting population dynamics. The goal of the study was to assess the individual consistency in the use of risky habitat types, and how habitat use was related to fitness components and life-history strategies. Using data from a closely monitored and harvested population of moose Alces alces, we examined how individual variation in offspring size, reproduction and survival was related to the use of open grasslands; a habitat type that offers high-quality forage during summer, but at the cost of being more exposed to hunters in autumn. The use of this habitat type may therefore involve a trade-off between high mortality risk and forage maximization. There was a high repeatability in habitat use, which suggests consistent behaviour within individuals. Offspring number and weight were positively related to the mothers' use of open grasslands, whereas the probability of surviving the subsequent harvest season was negatively related to the use of the same habitat type. As a consequence, we found a nonsignificant relationship between habitat use and lifetime fitness. The study suggests that harvesting, even if intended to be nonselective with regard to phenotypes, may be selective towards animals with specific behaviour and life-history strategies. As a consequence, harvesting can alter the life-history composition of the population and target life-history strategies that would be beneficial for individual fitness and population growth in the absence of hunting.

Fitness correlates of age at primiparity in a hunted moose population.

Trade-offs between fitness-related traits are predicted from the principle of resource allocation, where increased fecundity or parental investment leads to reduced future reproduction or survival. However, fitness traits can also be positively correlated due to individual differences (e.g. body mass). Age at primiparity could potentially explain variation in individual fitness either because early primiparity is costly, or it may lead to higher lifetime reproductive success. Based on long-term monitoring and genetic parentage assignment of an island population of moose, we quantified reproductive performance and survival, and examined whether early maturing females have higher total calf production than late maturing females. We explored if harvesting of calves affected the subsequent reproductive success of their mothers, i.e. also due to a post-weaning cost of reproduction, and whether there are any intergenerational effects of female reproductive success. There was a positive relationship between current and future reproduction. The probability to reproduce was lower for females that were unsuccessful the year before, indicating a strong quality effect on productivity. Females that started to reproduce as 2-year olds had a slightly higher total calf production compared to those starting at age three or four. High-performing mothers were also correlated with daughters that performed well in terms of reproductive success. Our results suggest that the observed individual heterogeneity in fitness could be associated with differences in age at primiparity. This heterogeneity was not affected by reproductive costs associated with tending for a calf post-weaning.

REVIEW: Can habitat selection predict abundance?

Habitats have substantial influence on the distribution and abundance of animals. Animals' selective movement yields their habitat use. Animals generally are more abundant in habitats that are selected most strongly. Models of habitat selection can be used to distribute animals on the landscape or their distribution can be modelled based on data of habitat use, occupancy, intensity of use or counts of animals. When the population is at carrying capacity or in an ideal-free distribution, habitat selection and related metrics of habitat use can be used to estimate abundance. If the population is not at equilibrium, models have the flexibility to incorporate density into models of habitat selection; but abundance might be influenced by factors influencing fitness that are not directly related to habitat thereby compromising the use of habitat-based models for predicting population size. Scale and domain of the sampling frame, both in time and space, are crucial considerations limiting application of these models. Ultimately, identifying reliable models for predicting abundance from habitat data requires an understanding of the mechanisms underlying population regulation and limitation.

Population properties affect inbreeding avoidance in moose.

Mechanisms reducing inbreeding are thought to have evolved owing to fitness costs of breeding with close relatives. In small and isolated populations, or populations with skewed age- or sex distributions, mate choice becomes limited, and inbreeding avoidance mechanisms ineffective. We used a unique individual-based dataset on moose from a small island in Norway to assess whether inbreeding avoidance was related to population structure and size, expecting inbreeding avoidance to be greater in years with larger populations and even adult sex ratios. The probability that a potential mating event was realized was negatively related to the inbreeding coefficient of the potential offspring, with a stronger relationship in years with a higher proportion or number of males in the population. Thus, adult sex ratio and population size affect the degree of inbreeding avoidance. Consequently, conservation managers should aim for sex ratios that facilitate inbreeding avoidance, especially in small and isolated populations.

Moose body mass variation revisited: disentangling effects of environmental conditions and genetics.

Large-scale geographical variation in phenotypic traits within species is often correlated to local environmental conditions and population density. Such phenotypic variation has recently been shown to also be influenced by genetic structuring of populations. In ungulates, large-scale geographical variation in phenotypic traits, such as body mass, has been related to environmental conditions and population density, but little is known about the genetic influences. Research on the genetic structure of moose suggests two distinct genetic lineages in Norway, structured along a north-south gradient. This corresponds with many environmental gradients, thus genetic structuring provides an additional factor affecting geographical phenotypic variation in Norwegian moose. We investigated if genetic structure explained geographical variation in body mass in Norwegian moose while accounting for environmental conditions, age and sex, and if it captured some of the variance in body mass that previously was attributed to environmental factors. Genetic structuring of moose was the most important variable in explaining the geographic variation in body mass within age and sex classes. Several environmental variables also had strong explanatory power, related to habitat diversity, environmental seasonality and winter harshness. The results suggest that environmental conditions, landscape characteristics, and genetic structure should be evaluated together when explaining large-scale patterns in phenotypic characters or life history traits. However, to better understand the role of genetic and environmental effects on phenotypic traits in moose, an extended individual-based study of variation in fitness-related characters is needed, preferably in an area of convergence between different genetic lineages.

Elucidating nematode diversity and prevalence in moose across a wide latitudinal gradient using DNA metabarcoding.

Parasitic nematodes are ubiquitous and can negatively impact their host by reducing fecundity or increasing mortality, yet the driver of variation in the parasite community across a wildlife host's geographic distribution remains elusive for most species. Based on an extensive collection of fecal samples (n = 264) from GPS marked moose (Alces alces), we used DNA metabarcoding to characterize the individual (sex, age class) and seasonal parasitic nematode community in relation to habitat use and migration behavior in five populations distributed across a wide latitudinal gradient (59.6°N to 70.5°N) in Norway. We detected 21 distinct nematode taxa with the six most common being Ostertagia spp., Nematodirella spp., Trichostongylus spp., T. axei, Elaphostrongylus alces, and an unclassified Strongylida. There was higher prevalence of livestock parasites in areas with larger sheep populations indicating a higher risk of spillover events. The individual level nematode richness was mostly consistent across study areas, while the number and type of nematode taxa detected at each study area varied considerably but did not follow a latitudinal gradient. While migration distance affected nematode beta-diversity across all sites, it had a positive effect on richness at only two of the five study areas suggesting population specific effects. Unexpectedly, nematode richness was higher in winter than summer when very few nematodes were detected. Here we provide the first extensive description of the parasitic nematode community of moose across a wide latitudinal range. Overall, the population-specific impact of migration on parasitism across the distribution range and variation in sympatry with other ruminants suggest local characteristics affect host-parasite relationships.

Camera collars reveal macronutrient balancing in free-ranging male moose during summer.

Understanding how the nutritional properties of food resources drive foraging choices is important for the management and conservation of wildlife populations. For moose (Alces alces), recent experimental and observational studies during the winter have shown macronutrient balancing between available protein (AP) and highly metabolizable macronutrients (total non-structural carbohydrates [TNC] and lipids). Here, we combined the use of continuous-recording camera collars with plant nutrient analyses and forage availability measurements to obtain a detailed insight into the food and nutritional choices of three wild moose in Norway over a 5-day period in summer. We found that moose derived their macronutrient energy primarily from carbohydrates (74.2%), followed by protein (13.1%), and lipids (12.7%). Diets were dominated by deciduous tree browse (71%). Willows (Salix spp.) were selected for and constituted 51% of the average diet. Moose consumed 25 different food items during the study period of which 9 comprised 95% of the diet. Moose tightly regulated their intake of protein to highly metabolizable macronutrients (AP:TNC + lipids) to a ratio of 1:2.7 (0.37 ± 0.002SD). They did this by feeding on foods that most closely matched the target macronutrient ratio such as Salix spp., or by combining nutritionally imbalanced foods (complementary feeding) in a non-random manner that minimized deviations from the intake target. The observed patterns of macronutrient balancing aligned well with the findings of winter studies. Differential feeding on nutritionally balanced downy birch (Betula pubescens) leaves versus imbalanced twigs+leaves across moose individuals indicated that macronutrient balancing may occur on as fine a scale as foraging bites on a single plant species. Utilized forages generally met the suggested requirement thresholds for the minerals calcium, phosphorus, copper, molybdenum, and magnesium but tended to be low in sodium. Our findings offer new insights into the foraging behavior of a model species in ungulate nutritional ecology and contribute to informed decision-making in wildlife and forest management.

Understanding scales of movement: animals ride waves and ripples of environmental change.

Animal movements are the primary behavioural adaptation to spatiotemporal heterogeneity in resource availability. Depending on their spatiotemporal scale, movements have been categorized into distinct functional groups (e.g. foraging movements, dispersal, migration), and have been studied using different methodologies. We suggest striving towards the development of a coherent framework based on the ultimate function of all movement types, which is to increase individual fitness through an optimal exploitation of resources varying in space and time. We developed a novel approach to simultaneously study movements at different spatiotemporal scales based on the following proposed theory: the length and frequency of animal movements are determined by the interaction between temporal autocorrelation in resource availability and spatial autocorrelation in changes in resource availability. We hypothesized that for each time interval the spatiotemporal scales of moose Alces alces movements correspond to the spatiotemporal scales of variation in the gains derived from resource exploitation when taking into account the costs of movements (represented by their proxies, forage availability NDVI and snow depth respectively). The scales of change in NDVI and snow were quantified using wave theory, and were related to the scale of moose movement using linear mixed models. In support of the proposed theory we found that frequent, smaller scale movements were triggered by fast, small-scale ripples of changes, whereas infrequent, larger scale movements matched slow, large-scale waves of change in resource availability. Similarly, moose inhabiting ranges characterized by larger scale waves of change in the onset of spring migrated longer distances. We showed that the scales of movements are driven by the scales of changes in the net profitability of trophic resources. Our approach can be extended to include drivers of movements other than trophic resources (e.g. population density, density of related individuals, predation risk) and may facilitate the assessment of the impact of environmental changes on community dynamics and conservation.

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.

Faecal metabarcoding provides improved detection and taxonomic resolution for non-invasive monitoring of gastrointestinal nematode parasites in wild moose populations.

BACKGROUND: Although wild ungulate populations are heavily monitored throughout Europe, we understand little of how parasites affect population dynamics, and there is no systematic, long-term monitoring of parasite diversity and parasite loads. Such monitoring is in part hampered by a lack of time- and cost-effective assay methodologies with high sensitivity and good taxonomic resolution. DNA metabarcoding has been successfully used to characterize the parasitic nemabiome with high taxonomic resolution in a variety of wild and domestic hosts. However, in order to implement this technique in large-scale, potentially non-invasive monitoring of gastrointestinal parasitic nematodes (GIN), protocol optimization is required to maximize biodiversity detection, whilst maintaining time- and cost-effectiveness. METHODS: Faecal samples were collected from a wild moose population and GIN communities were characterized and quantified using both parasitological techniques (egg and larva counting) and DNA metabarcoding of the ITS2 region of rDNA. Three different isolation methods were compared that differed in the volume of starting material and cell lysis method. RESULTS: Similar nematode faunas were recovered from all samples using both parasitological and metabarcoding methods, and the approaches were largely congruent. However, metabarcoding assays showed better taxonomic resolution and slightly higher sensitivity than egg and larvae counts. The metabarcoding was not strictly quantitative, but the proportion of target nematode sequences recovered was correlated with the parasitologically determined parasite load. Species detection rates in the metabarcoding assays were maximized using a DNA isolation method that included mechanical cell disruption and maximized the starting material volume. CONCLUSIONS: DNA metabarcoding is a promising technique for the non-invasive, large-scale monitoring of parasitic GINs in wild ungulate populations, owing to its high taxonomic resolution, increased assay sensitivity, and time- and cost-effectiveness. Although metabarcoding is not a strictly quantitative method, it may nonetheless be possible to create a management- and conservation-relevant index for the host parasite load from this data. To optimize the detection rates and time- and cost-effectiveness of metabarcoding assays, we recommend choosing a DNA isolation method that involves mechanical cell disruption and maximizes the starting material volume.

Coprophagy in moose: A first observation.

Coprophagy, the eating of feces, has been documented in a wide range of species but appears to be rare or difficult to detect in deer (Cervidae). Here, we report the first observation of coprophagy in moose Alces alces, which was recorded using camera collars on free-ranging moose in Norway. The footage shows an instance of allocoprophagy by an adult female moose in spring (May). We summarize the current knowledge about coprophagy in deer and briefly discuss potential drivers and possible implications for disease transmission. Further research is needed to determine whether coprophagy occurs frequently in moose and whether this behavior is positive (e.g., increased intake of nutrients) or negative (increased infection by parasites or pathogens).

Moose in our neighborhood: Does perceived hunting risk have cascading effects on tree performance in vicinity of roads and houses?

Like large carnivores, hunters both kill and scare ungulates, and thus might indirectly affect plant performance through trophic cascades. In this study, we hypothesized that intensive hunting and enduring fear of humans have caused moose and other forest ungulates to partly avoid areas near human infrastructure (perceived hunting risk), with positive cascading effects on recruitment of trees. Using data from the Norwegian forest inventory, we found decreasing browsing pressure and increasing tree recruitment in areas close to roads and houses, where ungulates are more likely to encounter humans. However, although browsing and recruitment were negatively related, reduced browsing was only responsible for a small proportion of the higher tree recruitment near human infrastructure. We suggest that the apparently weak cascading effect occurs because the recorded browsing pressure only partly reflects the long-term browsing intensity close to humans. Accordingly, tree recruitment was also related to the density of small trees 5-10 years earlier, which was higher close to human infrastructure. Hence, if small tree density is a product of the browsing pressure in the past, the cascading effect is probably stronger than our estimates suggest. Reduced browsing near roads and houses is most in line with risk avoidance driven by fear of humans (behaviorally mediated), and not because of excessive hunting and local reduction in ungulate density (density mediated).

Distribution, prevalence and intensity of moose nose bot fly (Cephenemyia ulrichii) larvae in moose (Alces alces) from Norway.

High host density combined with climate change may lead to invasion of harmful parasites in cervid (host) populations. Bot flies (Diptera: Oestridae) are a group of ectoparasites that may have strong impact on their hosts, but data on the current distribution, prevalence and intensity of the moose nose bot fly (Cephenemyia ulrichii) in Scandinavia are lacking. We estimated prevalence and intensity of nose bot fly larvae in 30 moose from southern and 79 moose from central Norway. All larvae detected were identified as the moose nose bot fly. We found surprisingly high prevalence in these areas, which are up to 1300 km south-southwest of the first published location in Norway and west of the distribution in Sweden. Prevalence (0.44-1.00) was higher in areas with higher moose density. Parasite intensity in hunter killed moose was higher in central Norway (mean 5.7) than southern Norway (mean 2.9), and in both regions higher in calves and yearlings than adults. Fallen moose had higher parasite intensity (mean 9.8) compared to hunter killed moose in the subsample from central Norway, suggesting a link to host condition or behavior. Our study provides evidence of parasite range expansion, and establishing monitoring appears urgent to better understand impact on host populations.

Identifying and correcting spatial bias in opportunistic citizen science data for wild ungulates in Norway.

Many publications make use of opportunistic data, such as citizen science observation data, to infer large-scale properties of species' distributions. However, the few publications that use opportunistic citizen science data to study animal ecology at a habitat level do so without accounting for spatial biases in opportunistic records or using methods that are difficult to generalize. In this study, we explore the biases that exist in opportunistic observations and suggest an approach to correct for them. We first examined the extent of the biases in opportunistic citizen science observations of three wild ungulate species in Norway by comparing them to data from GPS telemetry. We then quantified the extent of the biases by specifying a model of the biases. From the bias model, we sampled available locations within the species' home range. Along with opportunistic observations, we used the corrected availability locations to estimate a resource selection function (RSF). We tested this method with simulations and empirical datasets for the three species. We compared the results of our correction method to RSFs obtained using opportunistic observations without correction and to RSFs using GPS-telemetry data. Finally, we compared habitat suitability maps obtained using each of these models. Opportunistic observations are more affected by human access and visibility than locations derived from GPS telemetry. This has consequences for drawing inferences about species' ecology. Models naïvely using opportunistic observations in habitat-use studies can result in spurious inferences. However, sampling availability locations based on the spatial biases in opportunistic data improves the estimation of the species' RSFs and predicted habitat suitability maps in some cases. This study highlights the challenges and opportunities of using opportunistic observations in habitat-use studies. While our method is not foolproof it is a first step toward unlocking the potential of opportunistic citizen science data for habitat-use studies.

Cool as a moose: How can browsing counteract climate warming effects across boreal forest ecosystems?

Herbivory has potential to modify vegetation responses to climatic changes. However, climate and herbivory also affect each other, and rarely work in isolation from other ecological factors, such as plant-plant competition. Thus, it is challenging to predict the extent to which herbivory can counteract, amplify, or interact with climate impacts on ecosystems. Here, we investigate how moose modify climatic responses of boreal trees by using experimental exclosures on two continents and modeling complex causal pathways including several climatic factors, multiple tree species, competition, tree height, time, food availability, and herbivore presence, density, and browsing intensity. We show that moose can counteract, that is, "cool down" positive temperature responses of trees, but that this effect varies between species depending on moose foraging preferences. Growth of preferred deciduous trees was strongly affected by moose, whereas growth of less preferred conifers was mostly driven by climate and tree height. In addition, moose changed temperature responses of rowan in Norway and balsam fir in Canada, by making fir more responsive to temperature but decreasing the strength of the temperature response of rowan. Snow protected trees from browsing, and therefore moose "cooling power" might increase should a warming climate result in decreased snow cover. Furthermore, we found evidence of indirect effects of moose via plant-plant competition: By constraining growth of competing trees, moose can contribute positively to the growth of other trees. Our study shows that in boreal forests, herbivory cooling power is highly context dependent, and in order to understand its potential to prevent changes induced by warming climate, species differences, snow, competition, and climate effects on browsing need to be considered.

Geographical variation in the influence of density dependence and climate on the recruitment of Norwegian moose.

The effects of variation in climate on population dynamics are likely to differ within the distributional range of a species, yet the consequences of such regional variation on demography and population dynamics are rarely considered. Here we examine how density dependence and different climate variables affect spatio-temporal variation in recruitment rates of Norwegian moose using data collected over a large geographical area during the hunting season. After accounting for observation error by a Bayesian Markov chain Monte Carlo technique, temporal variation in recruitment rates was relatively independent of fluctuations in local population size. In fact, a positive relationship was as common as a density-dependent decrease in fecundity rates. In general, high recruitment rates were found during autumn 1 year after years with a warm February, and after a warm May or cold June in year t - 1 or in year t. Large regional variation was also found in the effects of some of the weather variables, especially during spring. These patterns demonstrate both direct and delayed effects of weather on the recruitment of moose that possibly operate through an effect of body mass on the proportion of the females that sexually mature as 1.5 or 2.5 years old.

Plasma lactate concentrations in free-ranging moose (Alces alces) immobilized with etorphine.

OBJECTIVE: To investigate plasma lactate concentrations of etorphine-immobilized moose in relation to environmental, temporal and physiological parameters. STUDY DESIGN: Prospective clinical study. ANIMALS: Fourteen female and five male moose (Alces alces), estimated age range 1-7 years. METHODS: The moose were darted from a helicopter with 7.5 mg etorphine per animal using projectile syringes and a dart gun. Once immobilized, the moose were approached, a venous blood sample was obtained and vital signs including pulse oximetry were recorded. Diprenorphine was administered to reverse the effects of etorphine. Timing of events, ambient temperature and snow depth were recorded. Blood samples were cooled and centrifuged before plasma was harvested and frozen. The plasma was thawed later and lactate analysed. Data were analysed using descriptive statistics and regression analysis. RESULTS: All animals recovered uneventfully and were alive 12 weeks after immobilization. Mean +/- SD plasma lactate was found to be 9.2 +/- 2.1 mmol L(-1). Plasma lactate concentrations were related positively to snow depth and negatively to time from induction of immobilization to blood sampling. The model that best described the variability in plasma lactate concentrations used induction time (time from firing the dart to the moose being immobilized). The second best model included induction time and snow depth. CONCLUSIONS AND CLINICAL RELEVANCE: Plasma lactate concentrations in these etorphine-immobilized moose were in the range reported for other immobilized wild ruminants. Decreasing induction time, which may be related to a more profound etorphine effect, and increasing snow depth possibly may increase plasma lactate concentrations in etorphine-immobilized moose.

Long-term changes in northern large-herbivore communities reveal differential rewilding rates in space and time.

Herbivores have important impacts on ecological and ecosystem dynamics. Population density and species composition are both important determinants of these impacts. Large herbivore communities are shifting in many parts of the world driven by changes in livestock management and exploitation of wild populations. In this study, we analyse changes in large herbivore community structure over 66 years in Norway, with a focus on the contribution of wildlife and livestock. We calculate metabolic biomass of all large-herbivore species across the whole region between 1949 and 2015. Temporal and spatial patterns in herbivore community change are investigated and we test hypotheses that changes in wildlife biomass are driven by competition with livestock. We find that total herbivore biomass decreased from 1949 to a minimum in 1969 due to decreases in livestock biomass. Increasing wild herbivore populations lead to an increase in total herbivore biomass by 2009. Herbivore communities have thus reverted from a livestock dominated state in 1949 (2% of large herbivore metabolic biomass comprised of wildlife species) to a state with roughly equal wildlife and livestock (48% of metabolic biomass comprised of wildlife species). Declines in livestock biomass were a modest predictor of wildlife increases, suggesting that competition with livestock has not been a major limiting factor of wild herbivore populations over the past decades. Instead there was strong geographic variation in herbivore community change, with milder lowland regions becoming more dominated by wild species, but colder mountain and northern regions remaining dominated by livestock. Our findings indicate that there has been notable rewilding of herbivore communities and herbivore-ecosystem interactions in Norway, particularly in milder lowland regions. However, Norwegian herbivores remain mostly regulated by management, and our findings call for integrated management of wild and domestic herbivores.

Temporal patterns of moose-vehicle collisions with and without personal injuries.

Collisions with wild ungulates are an increasing traffic safety issue in boreal regions. Crashes involving smaller-bodied deer species usually lead to vehicle damage only, whereas collisions with a large animal, such as the moose, increase the risk of personal injuries. It is therefore important to understand both the factors affecting the number of moose-vehicle collisions (MVCs) and the underlying causes that turn an MVC into an accident involving personal injuries or fatalities. As a basis for temporal mitigation measures, we examined the annual and monthly variation of MVCs with and without personal injuries. Using a 22-year-long (1990-2011) time series from Finland, we tested the effect of moose population density and traffic volume on the yearly number of all MVCs and those leading to personal injuries. We also examined the monthly distribution of MVCs with and without personal injuries, and contrasted the Finnish findings with collision data from Sweden (years 2008-2010) and Norway (years 2008-2011). Both moose population abundance indices and traffic volume were positively related to the yearly variation in the number of MVCs in Finland. The proportion of MVCs involving personal injuries decreased during our 22-year study period. The monthly distribution of all MVCs peaked during the autumn or winter depending on country, while MVCs involving personal injury peaked in summer. Our study indicates that efforts to reduce MVCs involving personal injuries need to address driver awareness and attitudes during summer, despite most MVCs occurring in autumn or winter.