Carnivore community structure and interactions in Scandinavia
We are studying determinant factors for mammalian carnivore community structure in Scandinavia, the nature of intraguild interactions and strategies for coexistence in a continuously changing environment. This will allow to improve the monitoring of complex carnivore communities and predict the outcome of management actions.
We are studying determinant factors for mammalian carnivore community structure in Scandinavia, the nature of intraguild interactions and strategies for coexistence in a continuously changing environment. This will allow to improve the monitoring of complex carnivore communities and predict the outcome of management actions.
Determinant factors for carnivore community structure
Carnivore communities in Scandinavia and all around the world are dramatically changing. Reductions in apex predator abundances can cause an increase in mesopredator abundance (i.e. mesopredator release), with a negative impact on the prey community through predation as well as on other small carnivores through intraguild predation. Additionally, bottom-up factors such as ecosystem productivity and habitat change may result in changes in resource availability, which could determine the relative strength and direction of trophic interactions. In this study we aim to assess how top-down (wolf and lynx presence) and bottom-up factors (winter severity, land productivity and human density) influence interactions among mesopredators (red fox, badger and pine marten). Furthermore, we will assess whether activity patterns shift under the influence of human factors such as human activity, fragmentation and land use. These factors may have important effects on how species use time and space, with important implications for the structure of the community and the coexistence of species. This study will be carried out in collaboration with long-term project Scandcam, which first goal is to optimize lynx monitoring using camera traps (http://viltkamera.nina.no/). The last years have tested camera traps in 7 study sties in Norway from Troms (69° N) to Østfold (59° S). This camera traps are providing valuable information on other mammalian species along a pronounced environment gradient, therefore a second goal is to detect changes in mammalian community structure.
Institutions and researchers from Sandcam: NINA John Odden (leader SCANDCAM Norway) Neri H Thorsen PHD NINA John Linnell SLU Umeå Jonas Kindberg SLU (leader SCANDCAM Sweden) Tim Hofmeester (post doc ) Joris Cromsigt SLU Grimsö Henrik Andrén Jens Persson |
The effect of prey dynamics in the interspecific interactions between predators
Resource partitioning is an important strategy for coexistence between sympatric carnivore species. When prey is abundant, several sympatric species may feed upon the same prey. However, when prey abundance decreases, interspecific competition may increase unless predators choose different alternative prey. Several medium and small sized predators, red fox, pine marten, stoat and least weasel, co-occur throughout the Scandinavian boreal forests. These species rely largely on rodents as their main prey, with the least weasel being the most specialized, and the potential for dietary overlap is therefore large. Research on boreal cyclic populations has mainly focused on the predator-prey interactions and the factors causing the population cycles. However, there is little information on the effect that those fluctuations have in the interspecific interactions of competing predators. We will use snow tracking data to assess potential changes in the interactions between medium and small sized predators (red fox, pine marten and small mustelids) influenced by fluctuations of their main prey and habitat characteristics such as snow condition.
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