Barbara Zimmermann

• PhD
• Professor at University of Inland Norway

Coexisting with wolves brings multifaceted societal challenges of high complexity, such as livestock losses due to depredation. Countries often support farmers with economic compensation of livestock losses. However, farmers affected by repeated depredation events might not only suffer economically, but also emotionally. The resulting increase in s...

We used GPS data from 71 wolves (Canis lupus) (>50 000 4h positions) from 23 years to study the selection of frozen waterbodies during winter in Scandinavia. Using Step-Selection Analyses, we compared GPS positions with randomly generated locations to answer: Do wolves use ice? When? And why? Wolves avoided lakes when there was no ice (barrier ef...

In the context of wolf recolonization of human-dominated European landscapes, wolves and humans are being coerced more and more into sharing the same space for their life activities. Traditional management of wolf/human co-occurrence heavily relies on minimizing overlap, encounters, and mutual disturbance to achieve coexistence: avoiding that wolve...

The ever-growing human population along with the expansion of settlements and land use, and effective hunting methods increasingly influence wildlife populations. Knowledge of management responses to re-establishing large carnivores is important to understand the overall impact of humans on large carnivores and their prey populations. We examined t...

Large carnivore populations have increased in many areas of Europe, resulting in socio-political conflicts, especially in areas with extensive outfield grazing systems. In Norway, the occurrence of large carnivores, especially brown bears (Ursus arctos) and grey wolves (Canis lupus), are largely separated from outfield grazing areas via carnivore m...

The return of large carnivores to areas with strong anthropogenic impact often results in conflicts among different interest groups. One cause of conflict is that large carnivores compete with humans for wild game species. In Scandinavia, the recolonization of wolves (Canis lupus) and brown bears (Ursus arctos) has important ramifications for the h...

To reach reproduction, individuals must survive the juvenile stage, a critical period of low survival rates in large carnivores. We analysed data from 582 wolves (Canis lupus) identified by DNA during their first year in Sweden and Norway, to investigate intrinsic and extrinsic factors within the natal territory affecting the probability to reach r...

Monitoring physiological indicators including heart rate (HR) is crucial for managing animal welfare across diverse settings, from precision livestock farming to wildlife conservation. HR is a reliable indicator of energy expenditure and stress, yet the invasive nature of HR loggers limits their application in wild and free-ranging species. This st...

Animals within social groups respond to costs and benefits of sociality by adjusting the proportion of time they spend in close proximity to other individuals in the group (cohesion). Variation in cohesion between individuals, in turn, shapes important group‐level processes such as subgroup formation and fission–fusion dynamics. Although critical t...

Background The use of virtual fencing in cattle farming is beneficial due to its flexibility, not fragmenting the landscape or restricting access like physical fences. Using GPS (Global Positioning System) technology, virtual fence units emit an audible signal and a low-energy electric shock when crossing a predefined border. In large remote grazin...

With the recent recovery of large carnivores in Europe, preventive measures to protect livestock are on the rise. Fences that exclude carnivores from grazing areas have been proven as effective, but they can be costly as well as posing a barrier for wildlife. We studied the effect of exclosures of > 10 km² to protect sheep Ovis aries on the distrib...

Management of ungulate populations to the desired density and/or demographic composition are challenged by contrasting aims of different stakeholders. For example, hunters may want to maximize hunting opportunities whereas commercial forest owners may want to minimize moose densities to mitigate browsing damage. In addition, the return of large pre...

Efficient wildlife management requires precise monitoring methods, for example to estimate population density, reproductive success, and survival. Here, we compared the efficiency of drone (equipped with a RGB camera) and ground approaches to detect and observe GPS‐collared female moose Alces alces and their calves. We also quantified how drone (n...

The global energy demand is growing, and the world is shifting towards using more renewable energy, like increased onshore wind power development. We used Global Positioning System (GPS) and Very High Frequency (VHF) location data from adult, territorial wolves Canis lupus in Scandinavia (Sweden and Norway; 1999–2021), to examine the potential for...

During the 20th century, when large carnivores were subject to eradication in Norway, farmers started to release their livestock unsupervised in the forests during summer. Since 1970, Norway has committed to conserve large carnivores, which led to high losses in domestic sheep herds. Therefore, farmers are encouraged to use cattle instead, as cattl...

Have you ever wondered how we can watch animals in the wild without actually being near them? In Norway, cows roam freely in the deep forest during summer. While the cows enjoy the freedom, it can be tricky to keep them safe from carnivores like wolves and bears, as no shepherds or dogs protect the herds. Keeping an eye on the cows is important! Fa...

Widespread across the world, human and wolf populations frequently meet on the increasing overlaps in their activities and habitats. Human attitudes towards wolves are diverse, complex, and deeply rooted in various beliefs and interests. They can be inherently connected to fear, and this “fear of the unknown”, amplified by the species’ elusiveness,...

In Norway, cattle (Bos taurus) are released to large areas of boreal forest for summer grazing. To determine to what degree this practice challenges timber production and wildlife management, we need a better understanding of basic cattle ecology. What do cattle, typical grazers, feed on in a habitat typically used by browsers? We determined cattle...

Apex carnivores that rely primarily on predation play a central but complex role within scavenging ecology by potentially suppressing intra-guild competitors, but also facilitating them by providing a reliable supply of carrion. We investigated the competitive relationship between sympatric wolves (Canis lupus) and wolverines (Gulo gulo) in Norway...

Survival of juvenile ungulates represents an important demographic parameter that influences population dynamics within ecosystems. In many ecological systems, the mortality of juvenile ungulates is influenced by various factors, including predation by large carnivores, human hunting activities and weather. While wolves Canis lupus are known to pre...

Background Northern small mammal populations are renowned for their multi-annual population cycles. Population cycles are multi-faceted and have extensive impacts on the rest of the ecosystem. In 2011, we started a student-based research activity to monitor the variation of small rodent density along an elevation gradient following the Birkebeiner...

Efficient wildlife management requires precise monitoring methods, e.g., to estimate population density, reproductive success, and survival. Here, we compared the efficiency of drone and ground approaches to detect and monitor GPS-collared female moose (Alces alces) and their calves. Moreover, we quantified how drone (n = 42) and ground (n = 41) ap...

Background Monitoring the behavior of wild animals in situ can improve our understanding of how their behavior is related to their habitat and affected by disturbances and changes in their environment. Moose (Alces alces) are keystone species in their boreal habitats, where they are facing environmental changes and disturbances from human activitie...

Scavenging is an important part of food acquisition for many carnivore species that switch between scavenging and predation. In landscapes with anthropogenic impact, humans provide food that scavenging species can utilize. We quantified the magnitude of killing versus scavenging by gray wolves (Canis lupus) in Scandinavia where humans impact the ec...

Survival among juvenile ungulates is an important demographic trait affecting population dynamics. In many systems, juvenile ungulates experience mortality from large carnivores, hunter harvest and climate-related factors. These mortality sources often shift in importance both in space and time. While wolves (Canis lupus) predate on moose (Alces al...

Consequences of recolonizing carnivores on prey species remain unclear. So far, Scandinavian studies failed to detect distinct anti-predator behaviors of moose to wolves. They hypothesized that naivety to wolves is a result of human harvest, the main cause of mortality in moose. Here, we studied moose before, during and after close proximity even...

Norway has a long tradition with unattended free-ranging livestock, with sheep and cattle released into summer ranging areas annually. However, the recent return of large carnivores creates conflicts between the political goals to conserve carnivores and the agrarian goals to utilize forests and mountains for livestock production. In response, a po...

The investigation of carnivore feeding behavior helps to increase knowledge on carnivores' ecology and their role in affecting prey populations. Among the physical, behavioral, and environmental drivers of carnivore feeding patterns, those associated to individual traits of predators are among the most difficult to study. Alongside cluster checks o...

Precision farming technology, including GPS collars with biologging, has revolutionized remote livestock monitoring in extensive grazing systems. High resolution accelerometry can be used to infer the behavior of an animal. Previous behavioral classification studies using accelerometer data have focused on a few key behaviors and were mostly conduc...

Spatial patterns of human hunting and predation risk are mediated by the physical landscape, with human hunting risk often associated with habitat features contrasting those linked to risk from large carnivores. Risk patterns from hunters and large carnivores can also vary in time, which may allow prey species to adjust anti-predator strategies not...

Social organization in animals is a fundamental factor driving population dynamics and individual spatial distribution. Affiliation among kin is common in social groups, but kinship is no safeguard against intraspecific competition. Within social groups, the closest competitors are often related. In this study, we present 14 years of GPS-position m...

Landscape characteristics, seasonal changes in the environment, and daylight conditions influence space use and detection of prey and predators, resulting in spatiotemporal patterns of predation risk for the prey. When predators have different hunting modes, the combined effects of multiple predators are mediated by the physical landscape and can r...

The Anthropocene continuously escalates the challenges and threats faced by large carnivores in human-dominated landscapes. Given their unique conservation and management requirements, detailed insights into their behaviour in relation to human-induced risks are crucial to designing landscapes of coexistence for people and predators, containing key...

Counting is not always a simple exercise. Specimens can be misidentified or not detected when they are present, giving rise to unidentified sources of error. Deer pellet group counts are a common method to monitor abundance, density, and population trend. Yet, detection errors and observer bias could introduce error into sometimes very large (spati...

As wolves recolonize areas of Europe ranging from moderate to high anthropogenic impact, fear of wolves is a recurring source of conflict. Shared tools for evaluating wolf responses to humans, and comparing such responses across their range, can be valuable. Experiments in which humans approach wild wolves can increase our understanding of how wolv...

Humans pose a major mortality risk to wolves. Hence, similar to how prey respond to predators, wolves can be expected to show anti-predator responses to humans. When exposed to a threat, animals may show a fight, flight, freeze or hide response. The type of response and the circumstances (e.g., distance and speed) at which the animal flees are usef...

Simple Summary Humans extirpated the wolf Canis lupus from many regions of Europe. Today, the wolf is returning to many of these areas, and with it, people’s opposition due to its predatory habits on, among others, ungulate game species. Based on existing data on wolf prey selection, kill rates and territory size, we extrapolated the results from c...

Competition between apex predators can alter the strength of top‐down forcing, yet we know little about the behavioral mechanisms that drive competition in multipredator ecosystems. Interactions between predators can be synergistic (facilitative) or antagonistic (inhibitive), both of which are widespread in nature, vary in strength between species...

Species assemblages often have a non‐random nested organization, which in vertebrate scavenger (carrion‐consuming) assemblages is thought to be driven by facilitation in competitive environments. However, not all scavenger species play the same role in maintaining assemblage structure, as some species are obligate scavengers (i.e., vultures) and ot...

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Age at first reproduction constitutes a key life-history trait in animals and is evolutionarily shaped by fitness benefits and costs of delayed versus early reproduction. The understanding of how intrinsic and extrinsic changes affects age at first reproduction is crucial for conservation and management of threatened species because of its demograp...

Large carnivores play a key ecological role in nature, yet quantifying the effects of predation at large spatiotemporal scales remains challenging. Wolves and brown bears have recovered in Sweden, where they share the same staple prey, moose. This ecosystem is representative of the Eurasian boreal realm, and makes an interesting case study for expl...

High densities of ungulates can increase human-wildlife conflicts. Where forestry is an important economy, intensive browsing can lead to browsing damage, resulting in volume losses, poor stand regeneration, and reduced timber quality. The forestry industry thus looks for practical, long-term measures to mitigate browsing damage. We tested the effe...

As wild ungulate densities increase across Europe and North America, plant–herbivore interactions are increasingly important from ecological and economic perspectives. These interactions are particularly significant where agriculture and forestry occur and where intensive grazing and browsing by wild ungulates can result in economic losses to growi...

Predation from large carnivores and human harvest are the two main mortality factors affecting the dynamics of many ungulate populations. We examined long-term moose (Alces alces) harvest data from two countries that share cross-border populations of wolves (Canis lupus) and their main prey moose. We tested how a spatial gradient of increasing wolf...

In Recommendation 257 L (2016-2017), the Norwegian parliament asked the government to undertake an assessment of the Norwegian subpopulation of wolves on the grounds that an independent assessment of what can be defined as a viable population of wolves in Norway has never previously been conducted. The Ministry of Climate and Environment gave the N...

Several large carnivore populations are recovering former ranges, and it is important to understand interspecific interactions between overlapping species. In Scandinavia, recent research has reported that brown bear presence influences gray wolf habitat selection and kill rates. Here, we characterized the temporal use of a common prey resource by...

Habitat selection of animals depends on factors such as food availability, landscape features, and intra- and interspecific interactions. Individuals can show several behavioral responses to reduce competition for habitat, yet the mechanisms that drive them are poorly understood. This is particularly true for large carnivores, whose fine-scale moni...

The organization of ecological assemblages has important implications for ecosystem functioning, but little is known about how scavenger communities organize at the global scale. Here, we test four hypotheses on the factors affecting the network structure of terrestrial vertebrate scavenger assemblages and its implications on ecosystem functioning....

Food-caching animals can gain nutritional advantages by buffering seasonality in food availability, especially during times of scarcity. The wolverine (Gulo gulo) is a facultative predator that occupies environments of low productivity. As an adaptation to fluctuating food availability, wolverines cache perishable food in snow, boulders, and bogs f...

The recovery of large carnivores in human-dominated landscapes comes with challenges. In general, large carnivores avoid humans and their activities, and human avoidance favors coexistence, but individual variation in large carnivore behavior may occur. The detection of individuals close to human settlements or roads can trigger fear in local commu...

Young forest stands and clearcuts in the boreal forest created by modern forestry practices along with meadows of abandoned summer farms may contribute as feeding areas for beef cattle. The patchy distribution and varying quality and diversity of forage on such unimproved lands may affect cattle productivity. Weight gain of 336 beef cows and 270 ca...

Advantages of low input livestock production on large pastures, including animal welfare, biodiversity and low production costs are challenged by losses due to undetected disease, accidents and predation. Precision livestock farming (PLF) enables remote monitoring on individual level with potential for predictive warning. Body temperature (Tb) and...

The wolf population in Scandinavia is regulated by hunting. Therefore, wolf effects on prey populations are limited compared to unregulated predator populations, and confined to the area of stationary, territorial packs and pairs. One way of estimating the effect of wolf predation on moose compared to moose harvest, is to study moose dynamics in wo...

The wolf is a social carnivore, with 80-90% of all individuals in the population living in packs or pairs within territories that are actively defended against conspecifics. The remaining individuals are solitary wolves. Solitary wolves can be categorized into 1) stationary animals within an established territory, and 2) non-stationary solitary ani...

Predation and human harvest are the two most important factors affecting the dynamics of many ungulate populations worldwide. The re-establishment of the wolf population in Scandinavia has been heavily opposed from several societal groups. One of the main arguments against wolves is that their predation will result in a significant reduction in the...

Along with the recent re-colonization of carnivores, a number of studies have shed new light on the potential importance of top predators for biodiversity and ecosystem functioning. Large carnivores may affect plant growth and biodiversity in forest systems through their effect on herbivores, i.e. the tri-trophic cascade hypothesis. In this study,...

Understanding the distribution of biodiversity across the Earth is one of the most challenging questions in biology. Much research has been directed at explaining the species latitudinal pattern showing that communities are richer in tropical areas; however, despite decades of research, a general consensus has not yet emerged. In addition, global b...

Natal habitat preference induction (NHPI) occurs when characteristics of the natal habitat influence the future habitat selection of an animal. However, the influence of NHPI after the dispersal phase has received remarkably little attention. We tested whether exposure to humans in the natal habitat helps understand why some adult wolves Canis lupu...

Multiple use of communal forests requires informed management to balance divergent interests such as livestock grazing and timber production. In this study, we examined the habitat selection of free-ranging beef cattle in two vegetation-mapped communal forests of Norway's boreal zone. The two areas were 35 km apart, and they mainly differed regardi...

Cattle released for summer grazing in south-boreal forest are free to select among a broad range of habitats. The goal of this study was to identify the factors influencing the microhabitat selection of such free-ranging beef cattle, for grazing and resting. We equipped sixteen female adult cows with GPS collars and activity sensors in southeastern...

Natal dispersal is an important mechanism for the viability of populations. The influence of local conditions or experience gained in the natal habitat could improve fitness if dispersing individuals settle in an area with similar habitat characteristics. This process, defined as ‘natal habitat-biased dispersal’ (NHBD), has been used to explain dis...

The wolf is a habitat generalist with reproducing populations in a variety of habitats from arctic areas, vast boreal forests, open agricultural areas to densely populated areas in the subtropics. An important factor for wolf habitat selection is the availability of prey, and several studies have shown that wolves utilize the dark hours for hunting...

The basic social unit in wolves consists of the territory-marking pair, and together with their offspring from the contemporary and/or previous litters they form a family group, commonly referred to as the wolf pack. The family group's grouping behavior and movement pattern depends on the wolves' year cycle. Observations in Scandinavia from long-te...

We investigated whether the degree of natal exposure to anthropogenic influences could explain some of the variation in the selection of habitat with regard to anthropogenic factors in Scandinavian wolves. In the first part of the study we tested whether anthropogenic influences in the natal habitat might affect the choice of a breeding territory....

We present the first telemetry study of the habitat use of dispersing wolves in Scandinavia. During dispersal, young wolves enter unfamiliar areas, and their travel routes often follow natural as well as anthropogenic landscape corridors such as valleys and roads. With average dispersal distances of 225 km (males) and 154 km (females), dispersing w...

People living inside wolf territories may observe wolves or wolf tracks near their homes, and debates often arise about wolves’ proximity to human settlements and whether the observed behaviors are normal for wild wolves. This has been the case in the so-called Slettås wolf territory in Eastern Hedmark where wolves first established a territory dur...

The territory establishment of the Slettås wolves in an area that for truly more than a hundred years had been free of reproducing wolves initiated a still ongoing conflict regarding the wolves’ behavior towards human settlement. Local inhabitants perceived the Slettås wolves as bold, and therefore the management marked the breeder pair and four pu...

Identifying how sympatric species belonging to the same guild coexist is a major question of community ecology and conservation. Habitat segregation between two species might help reduce the effects of interspecific competition and apex predators are of special interest in this context, because their interactions can have consequences for lower tro...