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1. Bumble bees fill an important function in temperate, boreal and alpineecosystems as pollinators of wild plants and cultivated crops. Global declines in popula-tion size of many bumble bee species call for knowledge about how habitats inuencedby human land use can be managed to accommodate diverse bumble bee communities.2. We carried out a field experiment to study effects on bumble bee communities inpower-line clearings in response to different vegetation clearing practices: (i) cutting,(ii) cutting and removing, and (iii) not cutting the woody vegetation, whilst simulta-neously assessing the effect of environmental variables, both individually and in interac-tion with treatment.3. Cutting the woody vegetation improved habitat quality for bumble bees relative tothe uncut treatment, whereas removal of woody debris provided no additional benet.The treatment effect on bee richness, diversity, abundance, and the abundance of gener-alist bees depended on local forb species richness. Increasing functional variation offorbs and cover of forbs with nectar tubes were positiv ely related to species richnessand abundance of bees, irrespective of treatment.4. The abundance of specialized long-tongued and late emerging bumble bees –which are of special conservation interest – were higher in the cut and cut-remove treat-ments and increased with functional variation of forb species irrespective of treatments.5. Management to improve habitat conditions for bumble bees in power-line clearingsdoes not require costly removal of woody debris after cutting, but more frequent cuttingcan benefit specialized bumble bee species of particular conservation interest.Key words. Boreal forest, bumble bee conservation, flower resources, functionaldiversity, habitat management, pollinator community

Insect pollination plays a vital role for the yield of many crops, such as apples, strawberries and coffee, which are economically significant commodities on the global market. Yet, knowledge about the role of insect pollination is lacking for many cash crops that support the livelihoods of small-scale farmers in developing countries. To assess if yields of watermelon are pollen limited, we conducted a supplemental hand-pollinated experiment (using a pollen mixture of cross and self-pollen) in 13 small-scale farms in an agricultural landscape in the Kilimanjaro and Arusha regions in northern Tanzania. We assessed fruit set, fruit abortion and weight of the mature fruits stemming from hand pollinated and control flowers. To check if differences in yield responses between hand-pollinated and control treatments depended on resource availability, we also accounted for local soil conditions. We found that hand pollination (i) increased the probability of fruit initiation by 30%, (ii) reduced the probability of fruit abortion by 13%, (iii) increased the probability of flowers developing into mature fruits by 42% and (iv) increased average fruit weight by 1.3 kg (±0.15 SE). Our results indicate that our system is pollen limited, due to insufficient visitor frequency and/or inefficient pollinator species. Fruit initiation and fruit weight were positively related to soil carbon, irrespective of treatment. The influence of soil moisture was not consistent across the measured responses, and differed between hand-pollinated and the control treatments. We suggest that farmers in our focal area should focus on improving the quality of the landscape to sustain and enhance healthy pollinator communities ultimately improving yields. We also suggest that farmers should continue current practices with respect to fertilization. The role of soil moisture on fruit initiation and maturation should be investigated to ensure that the positive effects of pollen is not hindered by soil moisture conditions.

To cope with periods of low food availability and unsuitable environmental conditions (e.g., short photoperiod or challenging weather), many heterothermic mammals can readily go into torpor to save energy. However, torpor also entails several potential costs, and quantitative energetics can, therefore, be influenced by the individual state, such as available energy reserves. We studied the thermal energetics of brown long-eared bats (Plecotus auritus) in the northern part of its distributional range, including torpor entry, thermoregulatory ability during torpor and how they responded metabolically to an increasing ambient temperature (Ta) during arousal from torpor. Torpor entry occurred later in bats with higher body mass (Mb). During torpor, only 10 out of 21 bats increased oxygen consumption (V̇O2) to a greater extent above the mean torpor metabolic rates (TMR) when exposed to low Ta. The slope of the torpid thermoregulatory curve was shallower than that of resting metabolic rate (RMR) during normothermic conditions, indicating a higher thermal insulation during torpor. During exposure to an increasing Ta, all bats increased metabolic rate exponentially, but the bats with higher Mb aroused at a lower Ta than those with lower Mb. In bats with low Mb, arousal was postponed to an Ta above the lower critical temperature of the thermoneutral zone. Our results demonstrate that physiological traits, which are often considered fixed, can be more flexible than previously assumed and vary with individual state. Thus, future studies of thermal physiology should to a greater extent take individual state-dependent effects into account.

Wild bees are key ecosystem components making their decline a cause for concern. An effective measure to increase wild bee diversity is to enhance plant diversity. However, the effect on bee diversity of augmenting plant diversity depends on site-specific environmental conditions. We aimed to make spatial predictions of where: (a) environmental conditions maximize bee diversity, so that such areas can be prioritized for augmenting plant diversity; and (b) populations of threatened wild bee species are most likely to occur. We surveyed bee communities in traditionally managed hay meadows in SE Norway and modelled bee diversity as a function of climate, habitat area, and distance to nesting substrates. We used independent data to validate our predictions and found that plant and predicted bee species richness together explained 76% and 69% of the variation in observed solitary bee species richness in forested and agricultural ecosystems, respectively. In urban areas, the predicted bee species richness alone explained 31% of the variation in observed solitary bee species richness. Using data from online species occurrence records, we found that – compared to species of lower conservation concern – threatened solitary bee species were more typically recorded in areas with a high predicted solitary bee species richness. We show that spatial predictions of bee diversity can identify sites where augmenting plant diversity is likely to be most effective. Maps of predicted bee diversity can guide species surveys and monitoring projects and increase the chances of locating populations of threatened bees.

Understanding the responses of different ontogenetic stages to environmental and human disturbance factors is essential for developing efficient conservation strategies for endangered plant species. We examined how three ontogenetic stages of a locally endangered tree species, Olea europaea subsp. cuspidata, responded to environmental factors and human disturbance in Hugumburda dry Afromontane forest in Ethiopia. We counted individual seedlings, saplings and adults of O. europaea in 70 20 × 20 m quadrats over ca. 2.8 ha, and measured biotic (woody species richness, canopy cover, aboveground tree biomass, herbaceous cover), abiotic (soil and topographic variables), and human disturbance factors (logging and tracks). To detect ontogenetic niche shifts, we compared observed vs. simulated locations of trees in the three life stages and how they related to the environmental and human disturbance factors. We found that the population structure of O. europaea showed generally low recruitment, with few seedlings per hectare compared with the abundance of saplings and adults. The probability of finding O. europaea individuals was influenced by biotic (woody species richness) and abiotic (soil depth, slope) environmental conditions and human disturbance (logging intensity), but the direction, strength and shape of the relationships differed between seedling, sapling and adult life stages, indicating ontogenetic niche shifts. All life stages showed a positive relationship with elevation. The observed environmental niches of the different lifestages of O. europaea, and their association with human disturbance levels, should be considered when conservation strategies are developed for this species. Human disturbance in terms of logging decreases the abundance of saplings, but may facilitate emerging seedlings through creation of gaps with improved light conditions. Recruitment is, however, very low in the study area, and seedlings should be protected from browsing to enhance survival. Woody species richness in general should be conserved to optimize conditions also for O. europaea saplings.

Conserving semi-natural grasslands, a threatened habitat type in European landscapes, is increasingly recognized as a measure to conserve pollinators. Our aim was to test if (a) prediction maps of solitary bee species richness could be used to rank semi-natural grasslands in terms of their potential for supporting wild bees, and (b) if such predictions extend current assessment criteria that determine which grasslands are eligible for being listed under habitat conservation schemes. We sampled wild bee communities in 52 semi-natural grasslands in southeast Norway. We conducted an across-year validation, using data from 2019 (32 sites) to model bee species richness, and used data from 2020 (20 sites) to validate predictions. We then conducted a leave-one-out cross-validation, iteratively using data from 51 sites to parameterize our model, and validating predictions on the withheld site. Finally, we used data from all 52 sites to update the model and tested if predicted species richness within the 1075 grasslands in our region was reflected in current assessment criteria scores assigned to those grasslands. Models from across-year, and leave-one-out cross-validations, predicted 39%, and 43% of bee species richness in semi-natural grasslands, respectively. Model predictions and current criteria of semi-natural grassland quality were not strongly related (R2 adjusted = 0.01), suggesting that prediction models can add a valuable extra dimension when prioritizing between semi-natural grassland for pollinator habitat conservation. Our findings illustrate how spatial prediction models can provide management authorities with a valuable tool for prioritizing where to direct habitat enhancement schemes in order to improve conservation effectiveness. Pollinators Bees Grassland Semi-natural Management Conservation

Global economic value of agriculture production resulting from animal pollination services has been estimated to be $235&ndash, $577 billion. This estimate is based on quantification of crops that are available at the global markets, and mainly originates from countries with precise information about quantities of agriculture production, exports, and imports. In contrast, knowledge about the contribution of pollinators to household food and income in small-scale farming at local and regional scales is still lacking, especially for developing countries where the availability of agricultural statistics is limited. Although the global decline in pollinator diversity and abundance has received much attention, relatively little effort has been directed towards understanding the role of pollinators in small-scale farming systems, which feed a substantial part of the world&rsquo, s population. Here, we have assessed how local farmers in northern Tanzania depend on insect-pollinated crops for household food and income, and to what extent farmers are aware of the importance of insect pollinators and how they can conserve them. Our results show that local farmers in northern Tanzania derived their food and income from a wide range of crop plants, and that 67% of these crops depend on animal pollination to a moderate to essential degree. We also found that watermelon&mdash, for which pollination by insects is essential for yield&mdash, on average contributed nearly 25% of household income, and that watermelons were grown by 63% of the farmers. Our findings indicate that local farmers can increase their yields from animal pollinated crops by adopting more pollinator-friendly farming practices. Yet, we found that local farmers&rsquo, awareness of pollinators, and the ecosystem service they provide, was extremely low, and intentional actions to conserve or manage them were generally lacking. We therefore urge agriculture authorities in Tanzania to act to ensure that local farmers become aware of insect pollinators and their important role in agriculture production.

Declining populations of wild pollinators have increased the interest in the management of human-modified landscapes for pollinator conservation. Modified landscape features, such as power-line clearings, may provide valuable habitats with increased floral resources for insect pollinators and solitary bees in particular. However, whether the effects of costly habitat interventions on bee communities in power-line clearings are sustained over time, is poorly understood. We conducted an experiment in 19 sites in power-line clearings across southeast Norway where the woody vegetation was; 1) cut and left to decay, 2) cut and removed, or 3) uncut. We assessed the temporal effects of habitat interventions and environmental factors on species richness, abundance, functional groups of nesting preference, body size, tongue-length, and species composition. Species richness and abundance of solitary bees increased substantially with time in both the cleared treatments. But compared to leaving the woody debris to decay, woody debris removal more than doubled estimated bee richness and abundance in areas with a higher forb richness and increased the trait variation in areas with high functional trait variation of forbs, dead wood, and available source habitats. The positive effect of woody debris removal on the species and functional trait diversity of bees was sustained during three years post-treatment, but the effect was dependent on abiotic and biotic environmental conditions. Over time the sites increasingly attracted bees from the regional species pool, showing how power-lines may benefit bee populations at a regional scale, through maintenance of temporary refugia in a forested landscape. The current routine practice (cut and left to decay) improves habitat quality for many bee species through alterations to early succession. However, our results indicate that the more costly woody debris removal is a more effective conservation measure for solitary bee communities over time and is to be recommended when funds are available. Removing the woody debris after routine maintenance clearing at specific sites may further enhance the diversity and persistence of bee populations over time, contributing to more diverse and stable bee communities. Keywords: Habitat management, Pollinators, Bee conservation, Forested landscape, Functional traits, Temporal effect

Agricultural practices to improve yields in small‐scale farms in Africa usually focus on improving growing conditions for the crops by applying fertilizers, irrigation, and/or pesticides. This may, however, have limited effect on yield if the availability of effective pollinators is too low. In this study, we established an experiment to test whether soil fertility, soil moisture, and/or pollination was limiting watermelon (Citrullus lanatus) yields in Northern Tanzania. We subjected the experimental field to common farming practices while we treated selected plants with extrafertilizer applications, increased irrigation and/or extra pollination in a three‐way factorial experiment. One week before harvest, we assessed yield from each plant, quantified as the number of mature fruits and their weights. We also assessed fruit shape since this may affect the market price. For the first fruit ripening on each plant, we also assessed sugar content (brix) and flesh color as measures of fruit quality for human consumption. Extra pollination significantly increased the probability of a plant producing a second fruit of a size the farmer could sell at the market, and also the fruit sugar content, whereas additional fertilizer applications or increased irrigation did not improve yields. In addition, we did not find significant effects of increased fertilizer or watering on fruit sugar, weight, or color. We concluded that, insufficient pollination is limiting watermelon yields in our experiment and we suggest that this may be a common situation in sub‐Saharan Africa. It is therefore critically important that small‐scale farmers understand the role of pollinators and understand their importance for agricultural production. Agricultural policies to improve yields in developing countries should therefore also include measures to improve pollination services by giving education and advisory services to farmers on how to develop pollinator‐friendly habitats in agricultural landscapes., Extra pollination increased the probability of a watermelon plant producing a second sellable fruit as well as fruit sugar content. Moreover, we learnt that, increased number of pollinators does not necessarily increase fruit set. Finally, we learnt that, increased fertilizer and watering/irrigation did not influence yield quality or quantity.

Understanding the relationship between biotic, abiotic and disturbance factors in dry degraded forests is crucial for effective conservation of endangered plant species. We studied the relationship between two locally endangered tree species, Olea europaea subsp. cuspidata and Juniperus procera, and environmental conditions in the Hugumburda dry Afromontane forest in Northern Ethiopia. We surveyed species richness of woody plants, herbaceous plant cover, soil and human disturbance factors from 70 plots (20 m × 20 m). The abundance of both species was positively correlated with each other, and with woody species richness and elevation. Moreover, the biomass of both species correlated positively with total tree biomass and number of O. europaea cut stumps. The positive relationship between O. europaea trees and cut stumps suggests that illegal selective logging is taking place in O. europaea-dominated areas. Based on the observed relationships we predict that conserving woody species may result in an increase in the abundance of both O. europaea and J. procera in the forest.

Browsing by ungulates may induce plant responses and affect subsequent plant food quality for other animals. Populations of many deer species have increased to unprecedented levels in Europe and North America. In Norway, population densities of red deer (Cervus elaphus) have increased over the past decades, but little is known about how increased deer browsing pressure may change the palatability of key food plants for other taxa in the boreal ecosystem. We conducted a cafeteria experiment to assess if long-term deer-browsing intensity affected the palatability of bilberry (Vaccinium myrtillus) leaves for leaf-eating larvae (mainly Lepidoptera). We found that leaf-eating insect larvae preferred bilberry leaves from the lightly browsed bilberry plants; the larvae consumed twice as much leaf biomass from the lightly browsed plants than from the unbrowsed and moderately browsed ones, and four times more than from highly browsed plants. Larvae never selected leaves from highly browsed plants as their first choice. Our study suggests that browsing-induced changes in the quality of shared food plants may be important in mediating indirect interactions between browsers of widely separated taxa. Whereas low levels of long-term red deer browsing increases the palatability of bilberry leaves for leaf-eating larvae, high browsing pressure reduces food consumption. Whether changes in palatability lead to changes in population densities of leaf-eating larvae remains to be studied, but any such adverse effects could have cascading ecological consequences for insectivorous birds and mammals.

Aim Because the ecological similarity between species is expected to increase with relatedness and that speciation is a local process, phylogeny may provide a common measure for the influence of ecological and biogeographic processes on community assembly. We tested if similarities in floral visitation patterns within communities and the phylogenetic beta-diversity among communities were related to the position of bees within the bee phylogeny. Location Global. Methods We combined a genus level phylogeny with within-genera phylogenies for the bee species occurring within 18 globally distributed bee-flower networks. Networks consisted of a matrix of bee and plant species and information on whether or not a bee species had been observed visiting flowers of a given plant species. For each network, we used Abouheif's Cmean to test if the similarity in floral associations (niche similarity) between bees and the number of plant species visited displayed a significant phylogenetic signal. To test if biogeography influenced the relatedness among species within networks we tested if the phylogenetic beta-diversity increased with geographical distance and dissimilarity in climatic conditions among networks. Results We found a phylogenetic signal for niche similarity in only 50% of the bee-flower networks. However, network size influenced the likelihood of observing a phylogenetic signal and for seven of the eight bee-flower networks with >20 species it was statistically significant. On a global scale, the phylogenetic beta-diversity increased with geographical distances and with climatic dissimilarity between sites. Main conclusions Bee communities are structured by processes of speciation and migration so that regional species pools are dominated by a subset of the global phylogenetic clades, resulting in increasing phylogenetic beta-diversity with geographical distance. Moreover, ecological filtering processes operating at both local (floral resource use) and continental (climatic constraints) scale determine the distribution of species among resources and geographical regions. The assembly of bee communities should therefore be understood as a product of both biogeographic and community ecological processes.

Powerline clearings are common in urban and semi-urban landscapes worldwide. The clearings could potentially promote flowering species associated with open-canopy habitats, and provide alternative habitat for species dependent on semi-natural grasslands, but the empirical evidence for this hypothesis is weak. We carried out a large-scale field study of understorey plant communities at 51 sites in powerline clearings and adjacent boreal forest. At each site, we placed four 4 m × 5 m plots with five 1-m 2 subplots in the clearing centre and a parallel set of plots 100 m into the adjacent forest. Habitat characteristics were sampled at plot and site level and from digital maps. The clearings had a higher richness of species associated with semi-natural grasslands, and a higher richness of shade-tolerant and shade-intolerant forb species. Total plant richness and diversity were higher in the clearings than in the forests. The magnitude of difference in species composition between clearings and forest, and plant community properties in the clearings, depended on the environmental context (age of the clearing, productivity, shading by tree regrowth, landscape fragmentation, climate). Our results indicate that over time, powerline clearings develop into novel habitats. Low-productive sites were dominated by Ericaceaous dwarfs shrubs. Richness of forbs and semi-natural grassland species in the clearings increased with productivity. Richness of shade-intolerant forbs and semi-natural grassland species increased with fragmentation of the surrounding landscape. We conclude that frequent clearing of productive sites can enhance plant biodiversity – including richness of insect-pollinated species – and mitigate the loss of species associated with semi-natural grasslands.

There is a need to quantify and better understand how wildlife interact with linear features, as these are integral elements of most landscapes. One potentially important aspect is linear feature tracking (LFT), yet studies rarely succeed in directly revealing or quantifying this behavior. In a proof-of-concept study, we employed short-term intensive GPS monitoring of red foxes (Vulpes vulpes) in a multiple-use landscape in southern Norway. Using periodic bursts of high frequency GPS position fixes, we performed modified path selection analyses to estimate the propensity of foxes to track natural and man-made linear features (roads, forest edges, and streams) once they are encountered. Foxes in our study tracked primarily forest edges and roads. Forty-three percent of bursts that encountered any linear feature resulted in LFT. LFT, although prominent, was manifested as a short-lived behavior, with overall median times to linear feature abandonment around two minutes. Movement speeds were highest along roads, perhaps due to greater ease of travel or higher perceived risk. In the highly heterogeneous habitats that characterize human-dominated landscapes, LFT may be manifested at such a fine spatio-temporal scale that it would remain hidden during telemetry studies employing conventional position fix frequencies. The approach described here may aid others studying spatial behaviors that are manifested over very short durations, yet are biologically significant.

Prioritizing where to implement management interventions is critical because managers have limited budgets and the effect of habitat enhancement depends on site-specific environmental conditions. Field experiments can identify the conditions where habitat enhancement is most effective, but are typically of limited extent and thus not sufficient for producing spatial predictions that can guide management efforts. We tested if we could produce spatial predictions maps – showing where management interventions to enhance bee habitat would be most successful – by combining spatial predictions of plant community composition (i.e., environmental conditions) obtained from field surveys with a field experiment, in which we quantified the effect of three types of management interventions on bee species richness. Using information from digital maps, we predicted plant species composition within power line clearings across southeast Norway. The intervention type, which involved cutting and removal of the woody vegetation, resulted in the largest increase in bee species richness, but the enhanced bee species richness was limited to clearings with forb-dominated vegetation. Importantly, the estimated effects on bee species richness did not differ between models using the predicted, versus the empirically observed, plant species composition as predictor, making it possible to produce spatial predictions of the increase in bee richness from implementing different management interventions. Synthesis and applications: Combining field surveys with data from field experiments can be used to produce high-resolution maps showing where wild bee habitat enhancement is likely to have the greatest effect. Such maps can inform decisions about where to allocate costly management interventions.

Inter‐specific interactions are important drivers and maintainers of biodiversity. Compared to trophic and competitive interactions, the role of non‐trophic facilitation among species has received less attention. Cavity‐nesting bees nest in old beetle borings in dead wood, with restricted diameters corresponding to the body size of the bee species. The aim of this study was to test the hypothesis that the functional diversity of cavity‐producing wood boring beetles ‐ in terms of cavity diameters ‐ drives the size diversity of cavity‐nesting bees. The invertebrate communities were sampled in 30 sites, located in forested landscapes along an elevational gradient. We regressed the species richness and abundance of cavity nesting bees against the species richness and abundance of wood boring beetles, non‐wood boring beetles and elevation. The proportion of cavity nesting bees in bee species assemblage was regressed against the species richness and abundance of wood boring beetles. We also tested the relationships between the size diversity of cavity nesting bees and wood boring beetles. The species richness and abundance of cavity nesting bees increased with the species richness and abundance of wood boring beetles. No such relationship was found for non‐wood boring beetles. The abundance of wood boring beetles was also related to an increased proportion of cavity nesting bee individuals. Moreover, the size diversity of cavity‐nesting bees increased with the functional diversity of wood boring beetles. Specifically, the mean and dispersion of bee body sizes increased with the functional dispersion of large wood boring beetles. The positive relationships between cavity producing bees and cavity nesting bees suggest that non‐trophic facilitative interactions between species assemblages play important roles in organizing bee species assemblages. Considering a community‐wide approach may therefore be required if we are to successfully understand and conserve wild bee species assemblages in forested landscapes.

Olea europaea L. subsp cuspidata (Wall. ex G. Don) Cif., an endangered tree species in dry Afromontane forests, has multiple uses in local communities in Ethiopia, making it susceptible to overexploitation. The study investigated the rates and causes of O. europaea harvesting in the Hugumburda National Forest Priority Area (NFPA). We measured the diameter at stump height of harvested stumps from 70 (20 &times, 20 m) plots and estimated the time since cutting to determine the biomass of O. europaea wood harvested annually in the forest. We performed a socioeconomic survey of the reasons for wood harvesting by conducting 163 stratified random individual interviews in the villages surrounding the forest. The average annual quantity of O. europaea wood illegally harvested from the forest was estimated to be 430 kg ha&minus, 1, mainly for farm implements, fuel wood, and fumigation purposes. The results of a General Linear Model (GLM) show that the extraction of O. europaea wood in the forest is higher at higher elevations than at lower, and the number of O. europaea stumps in the forest is higher at an intermediate distance to the villages. We show that O. europaea is harvested in the forest despite the fact that the forest is protected. Permanent sample plots should be established to monitor the increment.

Identifying the influence of stochastic processes and of deterministic processes, such as dispersal of individuals of different species and trait‐based environmental filtering, has long been a challenge in studies of community assembly. Here, we present the Univariate Community Assembly Analysis (UniCAA) and test its ability to address three hypotheses: species occurrences within communities are (a) limited by spatially restricted dispersal; (b) environmentally filtered; or (c) the outcome of stochasticity—so that as community size decreases—species that are common outside a local community have a disproportionately higher probability of occurrence than rare species. The comparison with a null model allows assessing if the influence of each of the three processes differs from what one would expect under a purely stochastic distribution of species. We tested the framework by simulating “empirical” metacommunities under 15 scenarios that differed with respect to the strengths of spatially restricted dispersal (restricted vs. not restricted); habitat isolation (low, intermediate, and high immigration rates); and environmental filtering (strong, intermediate, and no filtering). Through these tests, we found that UniCAA rarely produced false positives for the influence of the three processes, yielding a type‐I error rate ≤5%. The type‐II error rate, that is, production of false negatives, was also acceptable and within the typical cutoff (20%). We demonstrate that the UniCAA provides a flexible framework for retrieving the processes behind community assembly and propose avenues for future developments of the framework.

Summary Power line clearings are edge-creating disturbances in landscapes world-wide, but there have been few studies on their bordering vegetation. Our aim was to quantify edge effects on plant communities along such clearings in Norway and to identify factors that influence these edge effects. We surveyed understorey plant communities on either side of the power line clearing–forest edge at 51 sites, along four parallel transects at each site. Each transect had four plots located, respectively, in the clearing centre, clearing edge, forest edge and forest. We quantified the magnitude of edge effects (MEE) on either side by comparing edges with their corresponding ‘non-edge’ reference habitats. We also measured differences in species composition across the edge (clearing edge vs. forest edge). Habitat characteristics were sampled at plot and site level and from digital maps. Differences in species composition were greater between clearing centres and clearing edges than between forests and forest edges. Differences in species composition across the edge increased with edge contrast and forest productivity. Edge effects on species composition into the forest were smallest along north-facing edges, whereas those in the clearings increased with power line age. Species richness increased slightly towards the edge in forests but decreased considerably towards the edge in clearings. The direction and MEE on either side differed among functional groups. Edge contrast and edge aspect were the prime factors influencing the MEE into forests, whereas in clearings, these were influenced principally by tree regrowth in the clearings and by forest productivity. Synthesis and applications. Edge effects on plant communities bordering power line clearings were determined by factors that can be influenced by planners and managers. For existing power lines, management plans should differentiate between the following: (i) clearings through high conservation value forests, where edge effects into the adjacent forest should be limited; (ii) clearings that can act as replacement habitat for cultural landscape species, where maintaining open-canopy habitats should be prioritized; and (iii) ‘business-as-usual’ clearings, where continuing the current practice of cutting every 5–10 years is recommended.

The article Minor habituation to repeated experimental approaches in Scandinavian wolves, written by H. K. Wam & K. Eldegard & O. Hjeljord, was originally published Online First without open access.

The article From overlooking to concealed: predator avoidance in an apex carnivore, written by H. K. Wam & K. Eldegard & O. Hjeljord, was originally published Online First without open access.

Vast areas of the African savanna landscapes are characterized by tree‐covered Macrotermes termite mounds embedded within a relatively open savanna matrix. In concert with termites, large herbivores are important determinants of savanna woody vegetation cover. The relative cover of woody species has considerable effects on savanna function. Despite the potentially important ecological relationships between termite mounds, woody plants, large herbivores, and birds, these associations have previously received surprisingly little attention. We experimentally studied the effects of termites and large herbivores on the avian community in Lake Mburo National Park, Uganda, where woody vegetation is essentially limited to termite mounds. Our experiment comprised of four treatments in nine replicates; unfenced termite mounds, fenced mounds (excluding large mammals), unfenced adjacent savanna, and fenced savanna. We recorded species identity, abundance, and behavior of all birds observed on these plots over a two‐month period, from late dry until wet season. Birds used termite mounds almost exclusively, with only 3.5% of observations occurring in the treeless intermound savanna matrix. Mean abundance and species richness of birds doubled on fenced (large herbivores excluded) compared to unfenced mounds. Feeding behavior increased when large mammals were excluded from mounds, both in absolute number of observed individuals, and relative to other behaviors. This study documents the fundamental positive impact of Macrotermes termites on bird abundance and diversity in an African savanna. Birds play crucial functional roles in savanna ecosystems, for example, by dispersing fruits or regulating herbivorous insect populations. Thus, the role of birds in savanna dynamics depends on the distribution and abundance of termite mounds.

The species composition within communities is highly dependent on the rate of species immigration and whether immigrating species possess the functional traits required by the prevailing environmental conditions. Once established, random fluctuations in birth and death rates may reduce the diversity of ecologically equivalent species if local populations are not replenished by immigrating individuals. Consequently, three key processes drive community assembly: dispersal limitation, ecological filtering, and ecological drift. However, disentangling the relative contribution of these processes remains a challenge in community ecology. We used a binomial generalized linear mixed model to test whether the occurrences of solitary bees within 46 communities in southeast Norway were driven by (1) dispersal limitation, that is, the geographic distance to the nearest site where conspecifics occurred; (2) ecological filtering, that is, if forb species richness selected for non-Ericaceae-affiliated species; and (3) ecological drift, that is, if small, isolated communities were dominated by regionally common species. The regression slopes from the model for each potential driver of community composition were compared with those expected under a null model, in which species were treated as ecologically equivalent. Both dispersal limitation and ecological filtering influenced the probability of species occurring within communities. The occurrence of species decreased with elevation, and this relationship depended on the relative commonness of species and their floral preferences. For non-Ericaceae-affiliated species, the patterns of occurrence mirrored that expected under the null (neutral) model, resulting in the same patterns as would be expected under ecological drift. In contrast, the response of Ericaceae-affiliated species differed from what would be expected from the null model. Our results also indicate that processes leading to neutral dynamics in species compositions drive a large part of the gradient in species richness in Norwegian bee communities. These processes seem related to sampling effects so that large and interconnected communities have a higher probability of including regionally rare species than small, isolated communities. Our results suggest that targeting habitats—where the influence of ecological filtering is expected to be greater than that of neutral dynamics—can increase the success of habitat management plans aimed at promoting rare species.

A central goal in ecology is to develop theories that explain the diversity and distribution of species. The evolutionary history of species and their functional traits may provide mechanistic links between community assembly and the environment. Such links may be hierarchically structured such that the strength of environmental filtering decreases in a step-wise manner from regional conditions through landscape heterogeneity to local habitat conditions. We sampled the wild bee species assemblages in power-line strips transecting forests in south-eastern Norway. We used altitude, landscape diversity surrounding sites and plant species composition, together with total plant cover as proxies for regional, landscape and local environmental filters, respectively. The species richness and abundance of wild bees decreased with altitude. The reduction in species richness and abundance was accompanied by a phylogenetic clustering of wild bee individuals. Furthermore, regional filters followed by local filters best explained the structure of the functional species composition. Sites at high altitudes and sites with Ericaceae-dominated plant communities tended to have larger bees and a higher proportion of social and spring-emerging bees. When Bombus species were excluded from the analysis, the proportion of pollen specialists increased with the dominance of Ericaceae. Furthermore, we also found that the taxonomic, phylogenetic and functional compositional turnover between sites was higher in the northern region than in the southern part of the study region. Altogether, these results suggest that regional filters drive the species richness and abundance in trait-groups whereas local filters have more descrete sorting effects. We conclude that the model of multi-level environmental filters provides a good conceptual model for community ecology. We suggest that future studies should focus on the relationship between the biogeographical history of species and their current distribution, and on the assumption that closely related species do indeed compete more intensely than distantly related species.

Large carnivores may become dangerous if they habituate to humans. We repeatedly approached wild wolves Canis lupus throughout a year to test their individual response to human encounters (N = 141 trials). None of the at least 25 wolves present during the study visually or vocally exposed themselves. The wolves fled at a mean distance of 248 ± SE 11 m (range, 35–488 m). Their tolerance was most strongly influenced by the presence of site-dependent pups, while the distance at which they were initially alerted was most strongly influenced by detectability of human (wind and noise). The mean alert distance was 324 ± 19 m in the first and 264 ± 17 m in subsequent within-day trials, while tolerance distances showed no such trend, neither within a day nor throughout the year. The study indicates a high level of individual plasticity, making habituation difficult to predict.

The bees (Hymenoptera: Apiformes) are important pollinators in many ecosystems, but their diversity has declined in Europe during the past century, mainly due to habitat loss. However, some of the habitat requirements of wild bees are met in anthropogenic landscape elements, such as road sides, power-line strips and field edges. Moreover, as the bee species assemblages change throughout the season the habitat requirements of the bee fauna may change accordingly. Understanding such seasonally distinct responses of solitary bees with different phenologies may be of high value for local conservation planning. The purpose of this study was to examine if the habitat quality of field edges for solitary bees change throughout the season, and how this temporal variation relates to local habitat and landscape conditions. By sampling solitary bees in 18 field edges in southeast Norway throughout the season we found that the species richness and abundance of bees was highest in sun exposed field edges, independently of the season. However, we found phenologically distinct responses to the landscape context. Moreover, field edges situated in landscapes with a high proportion of forests and semi-natural landscape elements hosted the most phenologically diverse bee species assemblages. We conclude that in order to fulfil the habitat requirements of bee species assemblages throughout the season, one should conserve and direct habitat restoration schemes towards increasing sun exposure at field edges with a diverse flora and a high proportion of semi-natural areas in the vicinity.

Capsule Variables obtained from airborne laser-scanning (ALS) enabled slight or fair predictions of bird presence, and including multispectral data further improved predictions slightly.Aims To assess the usefulness of ALS as a tool for predicting species richness and single-species presence, and to investigate if including information from multispectral aerial images further improved predictability of bird presence.Methods Bird presence data were sampled in a Norwegian boreal forest reserve. Prediction models were developed for species richness and presence of the eight most abundant species by the use of two different modelling approaches: generalized linear models and the machine learning method random forest. Predictor variables were descriptors of three-dimensional forest structure obtained by ALS, and descriptors of tree species composition obtained from multispectral aerial images.Results Cross-validation of the prediction models indicated overall slight or fair predictive capability. Best predicti...

The decision to emigrate from the natal area can influence future fitness prospects, yet detailed data on sex-specific juvenile dispersal behaviour is still lacking for most bird species. We tracked 13 radio-tagged Tengmalm’s Owl Aegolius funereus juveniles from 13 different nests from fledging to independence and onwards. Six out of the seven female juveniles departed abruptly and disappeared from the natal area. In contrast, only one male juvenile departed abruptly, whereas the other five males and one female remained in the study area until tracking was terminated. We propose two alternative interpretations: (1) females initiated natal dispersal earlier than males, or (2) the manner of dispersal differed between the sexes, with females departing abruptly, and males moving gradually out of the natal area. We found no statistically significant influence of body condition or date of independence on dispersal behaviour. We suggest that early onset of dispersal and fast movements out of the natal area may increase a juvenile female’s chances of successful breeding in the following spring. In contrast to females, male Tengmalm’s Owls rarely breed as 1-year-olds, and the benefits of early/abrupt dispersal may be lower for juvenile males. We suggest that female-biased natal dispersal in Tengmalm’s Owl may come about through relatively higher lifetime reproductive success of early dispersing in females than in males.

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.

Post-fledging care constitutes a large proportion of the total costs of parental care in many bird species. Despite being recognized as of critical importance to the survival of the offspring and their recruitment into the breeding population, post-fledging care, including the relative contribution by male and female parents, is under-studied. In this study, we quantified food provisioning (prey deliveries) by male and female Tengmalm’s Owl (Aegolius funereus) parents to their offspring both in the nestling and the post-fledging stages, in years of differing natural prey abundance. Parents and at least one offspring in 26 families were fitted with radio-transmitters. Male parents exhibited higher delivery rates than did females throughout the late nestling and post-fledging stages, but the intersexual difference was smaller in broods that were not deserted by the female at any stage. The female deserted her mate and offspring at some stage in 63% of the broods. Overall, deserted males delivered more prey to their offspring than did non-deserted males. Delivery rates were generally higher post-fledging. Prey delivery rates differed among years, and were highest in low vole years (probably because of smaller prey items), intermediate in peak vole years, and lowest in years of vole increase. Prey delivery rates increased with increasing brood size for both sexes, but the response was stronger in females. We suggest that female Tengmalm’s Owls contribute less than males because they are in a position to decide on their level of provisioning effort first, and because of the potential for re-mating after deserting the first brood.

Within a family there are conflicts of interest between parents and offspring, and between male and female parents, over the supply of parental care. The observed pattern of parental care is the outcome of negotiations within the family, and may be influenced by environmental factors such as food abundance. We experimentally increased food supply to ten Tengmalm’s owl (Aegolius funereus) nests from hatching to fledging, mimicking natural cached prey. Ten un-supplemented nests served as controls. Parents and offspring were fitted with radio-tags. Food provisioning by parents was measured both in the (1) mid- and (2) late nestling stage and in the (3) early and (4) late post-fledging stage. In response to food supplementation, both males and females reduced food provisioning, but the effect was more pronounced in females. Females generally contributed much less to food provisioning than males, and food supplementation increased the difference between the sexes. Mass loss during the brooding stage was substantially lower for supplemented than for control females. Food supplementation did not improve offspring survival, and had no effect on body measurements of nestlings. In conclusion, parents of both sexes used the increased food supply to reduce the costs of caring for their current offspring, but females responded more strongly than males.

In species with biparental care, one parent may escape the costs of parental care by deserting and leaving the partner to care for the offspring alone. A number of theoretical papers have suggested a link between uniparental offspring desertion and ecological factors, but empirical evidence is scarce. We investigated the relationship between uniparental desertion and food abundance in a natural population of Tengmalm's owl Aegolius funereus , both by means of a 5-year observational study and a 1-year experimental study. Parents and offspring were fitted with radio-transmitters in order to reveal the parental care strategy (i.e. care or desert) of individual parents, and to keep track of the broods post-fledging. We found that 70 per cent of the females from non-experimental nests deserted, while their partner continued to care for their joint offspring alone. Desertion rate was positively related to natural prey population densities and body reserves of the male partner. In response to food supplementation, a larger proportion of the females deserted, and females deserted the offspring at an earlier age. Offspring survival during the post-fledging period tended to be lower in deserted than in non-deserted broods. We argue that the most important benefit of deserting may be remating (sequential polyandry).

Anthropogenic landscape elements, such as roadsides, hedgerows, field edges, and power line clearings, can be managed to provide important habitats for wild bees. However, the effects of habitat improvement schemes in power line clearings on components of diversity are poorly studied. We conducted a large‐scale experiment to test the effects of different management practices on the species, phylogenetic, and functional diversity of wild bees in power line clearings (n = 19 sites across southeastern Norway) and explored whether any treatment effects were modified by the environmental context. At each site, we conducted the following treatments: (1) Cut: all trees cut and left to decay in the clearing; (2) Cut + Remove: all trees cut and removed from the plot; and (3) Uncut: uncleared. The site‐specific environmental context (i.e., elevation and floral diversity) influenced the species, phylogenetic, and functional diversity within bee species assemblages. The largest number of species was found in the Cut + Remove treatment in plots with a high forb species richness, indicating that the outcome of management practices depends on the environmental context. Clearing of treatment plots with many forb species also appeared to alter the phylogenetic composition of bee species assemblages, that is, more closely related species were found in the Cut and the Cut + Remove plots than in the Uncut plots. Synthesis and applications: Our experimental simulation of management practices in power line clearings influenced the species, phylogenetic, and functional diversity of bee species assemblages. Frequent clearing and removal of the woody debris at low elevations with a high forb species richness can increase the value of power line clearings for solitary bees. It is therefore important for managers to consider the environmental context when designing habitat improvement schemes for solitary bees.

Boreal owls Aegolius funereus (referred to as Tengmalm's owls in Europe) breed in boreal forests throughout the Holarctic region and in high-elevation subalpine forests further south. They are currently classified as seven subspecies; six found throughout Eurasia, and one in North America. The geographic distribution of boreal owls in North America and Eurasia is similar, as are their patterns of dispersal and irruption. Because a recent genetic study of boreal owls in North America found very little genetic differentiation among widely disparate locations, we expected that boreal owls in Eurasia similarly would have very little genetic differentiation. Using seven microsatellite markers, we analyzed genetic samples from 275 boreal owls in North America, 36 in Norway, and five in eastern Russia. We found no detectable genetic differentiation between Norwegian and Russian owls, but notable differentiation between North American and Eurasian owls. Low intra-continental genetic differentiation likely results from high rates of long-distance dispersal among subpopulations of boreal owls. In light of these results, we recommend further genetic sampling of boreal owls throughout Eurasia in order to determine whether six separate subspecies here are warranted.

The relative contribution of each parent when providing for the fledglings has been recorded in only a few raptor species. We studied prey deliveries by Eurasian Sparrowhawk Accipiter nisus parents to fledglings at seven nests in southern Norway. Parents and young were fitted with radio-transmitters. Males delivered a larger number of prey to the young than did females throughout the post-fledging period (on average c. 80% of the deliveries). Two females were never observed to deliver food to the offspring, and their mates apparently raised the young to independence alone. The duration of the post-fledging period was positively related to per-capita delivery rate in the late stage.

Many prey species select bed sites that reduce the risk of being caught off guard. We investigated bed sites used by an apex predator (gray wolf, Canis lupus) before and after individuals were approached by humans (N = 48 trials). On 9 out of 10 days, the unprovoked wolves rested at sites high in the terrain with a good overview (overlooking sites). After being approached, they resettled on more concealed sites lower in the terrain. Solitary yearlings used less overlooking sites than adults both before and after disturbance. The study provides experimental evidence that wolves’ behavioural response to approaching humans is analogous to predator avoidance in prey species.

1. Amphibian species all over the world are in a decline due to climate change as well as human activities. To mitigate negative impacts on amphibians, especially in urban development areas, it is important to understand how human development impact the populations. 2. The goal of the study was to document the development of the Great Crested newt (Triturus cristatus) population in a developmental area with varying degrees of considerations to mitigate negative impacts on newts taken during the construction phase. The main objectives of the study were to assess changes during the last 10 years (2013-2022) in: 1) population size in the ponds based on (a) maximum count per capture session and (b) recaptures of identified individuals and capture-mark-recapture models; 2) average body mass of adults, to assess if there are indications of a decline 3) age structure. Based on identification of individuals from photos of ventral side patterns, I also investigated if there was evidence of movements between ponds, and the relative performance of manual versus automatic methods for individual recognition. 3. The data was collected from two ponds, Kjeller Gård pond (2013-2022) and Lundbydammen (2016-2022) The animals were captured in Ortmann-traps during several trapping sessions each year in each pond and the animals were photographed and weighed. The pictures were sorted manually and by use of the software Zooracle. Population size for the population Kjeller pond - based on capture-“mark” (i.e., photo)-recapture data of adult females and males - was estimated with Jolly-Seber population models; both closed and open population models. 4. Estimations of the population size in the Kjeller pond showed a decrease in population size from 2013 to 2016, an increase towards 2019 and a decrease from 2019 to 2022. A total decline from 2013 to 2022. Estimated population size from capture-mark-recapture models were consistently larger than the maximum number of individuals trapped during any trapping night (capture event), irrespective of year. However, the relative difference between maximum number of newts captured and estimated number of individuals was not constant among years. Thus, individual identification and capture-mark-recapture modelling is required to give reliable estimates of population size. The average body mass of the animals was shown to decrease from 2016 to 2022, and the females had a larger decline rate than the males. There was a larger population of recaptures than new animals, but there was no recruitment failure to either of the populations for Kjeller gård pond or Lundbydammen. There was only one observation of movements between the ponds, and only in this direction from Kjeller gård pond to Lundbydammen. Manual identification of the animals for recapture mark recapture proved the most effective in this study. Manual recognition identified more than twice as many animals as Zooracle. 5. The population in both ponds seems to have been affected by human activity. The populations had a negative development, and active measures should be taken to prevent further decline in the populations.

1. All the Norwegian bat species depend on forest habitats in some parts of their annual cycle. Despite many of the Norwegian bat species being categorised as threatened on the Norwegian Red List and playing key roles as controllers of insect populations, lack of knowledge about their ecological role in forests leads to them often being overlooked in management decisions. Bats can be grouped into foraging guilds depending on their foraging behaviors and call structure. This study focuses on short- range echolocating (SRE) bat species foraging on insects in open forest habitats. 2. The overall aim of the study is to gain more knowledge about the relationships between SRE bat activity and insect abundance within boreal forests of varying tree density. More specifically this study investigates (1) if and how the activity of SRE bats is influenced by forest density (canopy openness) and environmental variables (temperature, moisture), and if these relationships differs between feeding and commuting behaviours, (2) if and how the abundance of insects is influenced by canopy openness and environmental variables, and (3) whether there is a stronger positive correlation between bat feeding activity and insect abundance than between bat commuting activity and insect abundance. 3. Data was retrieved from sampling plots located in forest gaps in eleven mixed boreal forest sites in south-eastern Norway between May and September 2022. Bat activity and insect abundance were monitored with non- invasive methods, using bat acoustic detectors and insect camera traps. Site- specific soil moisture and temperature data were sampled using data loggers deployed into the soil. Hemisphere photos were taken at each site to calculate canopy openness as a proxy for forest density. 4. Results from this study show that forest density and environmental variables influenced bat feeding- and commuting activity differently. Bat feeding activity increased with higher canopy openness and decreased with higher temperatures. Bat commuting activity decreased with increasing soil moisture and temperatures. Insect abundance was positively influenced by moisture and had a negative relationship with temperature. The relationship between bat activity and insect abundance was positively influenced by low canopy openness but disappeared at higher openness. For commuting behaviour there was no clear relationship between bats and insects. Results from this study show that there are relationships between insect abundance and bat activity in forests that can be quantified with non- invasive monitoring. However, to fully understand this relationship, one must account for the influence of biotic and abiotic environmental variables. Key words: Insectivorous bats, flying insects, short- range echolocators, passive acoustic monitoring, insect camera traps, non- invasive, canopy openness, boreal forests

Insects constitute the world’s most diverse class of animals and are vital for ecosystem function, services, and human welfare. Bees are considered some of the world’s most important pollinators, and declining bee richness and abundance could have devastating effects on agricultural productivity and ecosystem stability. Habitat destruction has led to declines in food resources for bees in agricultural areas, entailing serious negative impacts on pollinator communities. To help mitigate this loss, increasing flower resource availability is essential, for example by sowing flower strips. The establishment of flower strips is an environmental scheme used throughout Europe, to increase the food resources available for pollinating insects in agricultural areas and prevent the decline in richness and abundance of pollinators. Nevertheless, the knowledge of how plant species composition affects bee diversity is limited. This thesis aims to assess how different plant species contribute to wild bee richness and to bee diversity within distinct trait groups i.e., sociality: social vs solitary, diet preference: specialist vs generalist, or taxonomic family. Thirty-two locations in Southeast Norway were sampled. Resource-seeking bees within the transects were collected using netting. In one-half of the locations, bees were sampled along transects with a sown flower strip on one side and roadside vegetation on the other. In the second half of the locations, bees were sampled along transects with a grain field on one side and roadside vegetation on the other. To assess plant species composition and abundance at different sites, vegetation squares were used to conduct a vegetation analysis. This study found that there was a great variance in which plant species bees were attracted to. Several key plant species stood out as popular plant species, contributing to both bee abundance and diversity. Additionally, bee traits, i.e., sociality, diet niche and taxonomic family, influenced the plant–bee interactions (attraction). Moreover, flower strips differed from the roadside in both abundance and species composition. This study provides insight into the network of interactions between wild bee species and plant species, and the plant preferences of bees based on some traits. This knowledge could improve the effect of flower strips as an environmental scheme, potentially improving the quality of flower strips to support a larger variety of bee species