Multispecies Interactions

Although the Scandinavian population is currently stable, the management of bears remains controversial and under public scrutiny as stakeholders from different backgrounds often desire disparate conservation outcomes. It is therefore critical that managers in Scandinavia are provided both accurate and up-to-date information about the status and ecology of the local bear population.

This research project takes advantage of the SBBRP’s core resources and expertise, and the convergence of research efforts in Sweden’s Ljusdal area, to explore several important knowledge gaps related to brown bears and multispecies interactions. This is particularly important in the context of the shifting paradigm in Scandinavia from single species to multispecies management. Our goal is to capitalize on the simultaneous collaring of bears, wolves, moose, and red deer in the Ljusdal area to broadly evaluate predation patterns, predator-prey behavior, and predator-predator interactions.

Research Goals

1) Quantify moose predation in a multi-predator environment

Brown bears are apex predators that can affect the population dynamics of their prey. Newborn moose are the primary prey for bears in Scandinavia, and previous SBP research has estimated the kill rate of bears on both neonate and adult moose and explored their potential effect on the moose population. However, previous kill rate estimates utilized outdated technology and are also now over 10 years old. Furthermore, these studies were conducted when bears were the only predator of moose in the core bear distribution area in Sweden; wolves have subsequently recolonized the area and overlap with the bear population. The environment in Scandinavia also has subsequently been, and will continue to be, affected by climate change. Changing climate and weather patterns, alongside shifting plant and animal distributions, will continue to alter Scandinavia’s boreal forest ecosystem. Thus, it is time to reexamine our baseline understanding of bear-moose interactions in Scandinavia by a) capitalizing on novel GPS technologies, and b) placing bear predation in the current environmental and multi-predator context.

We plan to produce a robust, updated, and accurate portrayal of the combined effect of bear and wolf predation on the moose population in Scandinavia.

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Brown Bears

Wolves

Wolverine

2) Explore and quantify drivers of bear kill rates

There are multiple environmental and anthropogenic factors that may alter bear kill rates. For example, the availability of alternative prey species may either relax or strengthen predation on a primary prey, depending on the species and context. The availability of alternative food sources, other than ungulate prey, can also alter bear foraging patterns. For bears, the seasonal cycling of important fall foods, such as whitebark pine cones in Yellowstone National Park, USA, has been shown to alter meat consumption patterns, i.e., bears utilize meat more when pine cones are less abundant. In Scandinavia, it remains unknown whether seasonal variation in berry production effects predation on moose and to what extent. Furthermore, the SBP has shown that human disturbance effects bear behavior in Scandinavia. However, it remains unclear whether the anthropogenic landscape alters moose habitat use and subsequent bear predation patterns.

Our first goal is to quantify the extent to which bears use red deer as prey and explore the potential effect of red deer prey-use on the moose population. Next, we will explore the effect of berry production, a primary fall food source, on bear predation patterns. Finally, we will evaluate the effect of anthropogenic landscape features on bear-moose predation patterns.

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Alternative Prey

Fall Food Abundance

Human Disturbance

3) Explore multispecies interactions and behavior

Bears and moose do not exist in a vacuum. They move through landscapes that are heavily dominated by humans and interact with other large ungulates and carnivores in the ecosystem, all of which can affect their behavior and their interactions, including predation patterns and subsequent moose population trends. For example, bears compete with other predators, which may affect their behavior. Although recent SBP research has quantified the effect of bears on wolves kill rates, we still know little about how wolves affect bears in Scandinavia. For example, it is likely that wolves provide food subsidies to bears via kills, as bears often visit wolf kill sites. But it is also possible that competition from wolves may limit access to shared prey resources, such as neonate moose, thus decreasing their overall kill rate. The SBP has provided managers with a wealth of knowledge surrounding the biology and ecology of bears in Scandinavia and is currently leading the way in exploring competition between bears and wolves. However, there is still a lot we do not understand about the nature of competition between sympatric carnivores in Scandinavia and their combined effect on prey population dynamics, which is particularly relevant for species such as moose that are subject to both natural predation and human harvest.

We hope to utilize novel technology to explore fine-scale interactions between bears, wolves, moose, and red deer. Proximity triggered GPS collars are a novel technology that allow for the detailed study of a focal species. Although this data will be collected opportunistically (i.e., when our focal animals come within a certain distance from one another), the dataset will be wholly unique.