Bodil Elmhagen

Home

Publications: Abstract

Results in short

Study area
- About Fennoscandia

Scientific background

In Swedish

     
 

Abstract

Carnivore conservation in practice:
replicated management actions on a large spatial scale.

1. More than a quarter of the world’s carnivores are threatened, often due to multiple and complex causes. Considerable research efforts are devoted to resolving the mechanisms behind these threats in order to provide a basis for relevant conservation actions. However, even when the underlying mechanisms are known, specific actions aimed at direct support for carnivores are difficult to implement and evaluate at efficient spatial and temporal scales.

2. We report on a 30-year inventory of the critically endangered Fennoscandian arctic fox Vulpes lagopus L., including yearly surveys of 600 fox dens covering 21 000 km2. These surveys showed that the population was close to extinction in 2000, with 40–60 adult animals left. However, the population subsequently showed a fourfold increase in size.

3. During this time period, conservation actions through supplementary feeding and predator removal were implemented in several regions across Scandinavia, encompassing 79% of the area. To evaluate these actions, we examined the effect of supplemental winter feeding and red fox control applied at different intensities in 10 regions. A path analysis indicated that 47% of the explained variation in population productivity could be attributed to lemming abundance, whereas winter feeding had a 29% effect and red fox control a 20% effect.

4. This confirms that arctic foxes are highly dependent on lemming population fluctuations but also shows that red foxes severely impact the viability of arctic foxes. This study also highlights the importance of implementing conservation actions on extensive spatial and temporal scales, with geographically dispersed actions to scientifically evaluate the effects. We note that population recovery was only seen in regions with a high intensity of management actions.

5. Synthesis and applications. The present study demonstrates that carnivore population declines may be reversed through extensive actions that target specific threats. Fennoscandian arctic fox is still endangered, due to low population connectivity and expected climate impacts on the distribution and dynamics of lemmings and red foxes. Climate warming is expected to contribute to both more irregular lemming dynamics and red fox appearance in tundra areas; however, the effects of climate change can be mitigated through intensive management actions such as supplemental feeding and red fox control.

Reference
Angerbjörn A, Eide NE, Dalén L, Elmhagen B, Hellström P, Ims RA, Killengreen S, Landa A, Meijer T, Mela M, Niemimaa J, Norén K, Tannerfeldt M, Yoccoz NG, Henttonen H (2013) Carnivore conservation in practice: replicated management actions on a large spatial scale. Journal of Applied Ecology 50: 59–67.

 
     
 
Arctic fox den. This den covers 30x30m and has 50 openings. Arctic fox dens are typically this large and also easy to spot, as the vegetation has been fertilised by fox faeces and prey remains. This project reports arctic fox population trends over 30 years, based on yearly surveys of 600 dens in Sweden, Norway and Finland.

 

 
 
Arctic fox with a feeding station in the background. As a result of actions -supplementary feeding at arctic fox dens and control of an expanding population of competitors (red foxes) - the arctic fox population in Sweden has increased.
 
Feeding station. The black container is filled with dog food pellets which the arctic fox reaches through a tunnel. The tunnel keeps out larger predators, such as wolverine, and birds. In winter, the arctic foxes were also supplied with meat.
 

The red fox increased in the mountain tundra in the 20th century. It is larger than the arctic fox and takes over arctic fox dens and territories. It can monopolize food sources such as carcasses and sometimes kill arctic foxes.