We just finished another round of camera trapping. Camera traps are cameras that are triggered by a passive-infrared sensor that detects movement of warmblooded animals. We use these to see which animals are present in the forest with the aim to detect patterns in the presence and abundance of animals in specific patches of the forest. Because larger animals trigger the camera better than smaller animals, we need to take some measurements which enable us to correct for these differences. For this we use a grid of sticks in front of the camera as can be seen on one of the images.
Researchers, conservationists, hunters and landowners are confronted with an important question: What is a reliable, time and cost efficient method to monitor changing wildlife communities? Which method is most suitable to identify how many animals there are in an area? Is there one method that would work well for several species? To investigate these questions, our recently published article compared dung counts with camera trapping to estimate population densities of moose (Alces alces) and roe deer (Capreolus capreolus) in northern Sweden.
Often it is difficult to find dung and/or specify the correct species and some of these challenges emerged in our results. We found that dung counts and camera trapping estimated similar densities for moose, which were also comparable to independent estimates from local managers. This follows our expectations since moose dung is large and can be identified and detected with relative ease. In contrast, dung counts appeared to underestimate roe deer densities when compared to camera trapping. Dung of roe deer is relatively small which decreases detectability. The large overlap in dung morphology among roe deer, red deer and fallow deer may also influence density estimates from dung counts. This highlights the value of camera trapping in multi-species ungulate communities. Estimates of detection distance and angle from modelled versus raw camera data resulted in nearly identical outcomes. However, the telemetry-derived daily movement rate for moose and roe deer resulted in much higher density estimates than the camera trap-derived estimates.
The simplified use of a well-developed camera trapping method holds great potential for citizen science-based programs (e.g., involving hunters) that can track the rapidly changing European wildlife landscape. We suggest to include camera trapping into management programs, where data can be analysed via web-based applications.
Would you like to know more? Have a look at our article at
The purpose of the monthly sampling was to collect data over a 12-month period to investigate trophic interactions among ungulate species along gradients of land-use and species community composition at a high temporal resolution. This study places its main focus on moose, red deer, roe deer and fallow deer, but reindeer and wild boar were also included when present. The land-use gradient of primary interest was the proportion of agriculture versus semi-natural habitats, i.e. forests and wetlands. Data was collected every month on tracts in each of our two reference areas: Västerbotten and Sörmland. At the tract scale (1 km2), the ungulate community composition is currently still largely unresolved. Although all trophic interactions between the different ungulates are of interest in ‘Beyond Moose’, the study areas offer the unique opportunity to investigate two particularly intriguing scenarios: In the north, Swedish moose are for the first time in history confronted with an expanding population of red deer while in the south they are faced with fallow deer who have rapidly grown to locally extreme numbers over the past three decades. In total, we collected 1.400 samples which will now be analyzed using DNA metabarcoding to determine the diet composition throughout the year.
And here a short clip of our DNA extraction robot doing its job (requires Flash Plugin):
...and it was once again time to do the inventory in our 10 seasonal exclosures in and around Öster Malma. We spent 11 long field days in the exclosures to measure field vegetation and tree density. We also followed up our individually marked trees and recorded how much they grew since last spring and if they were browsed. In total an exhausting but successful period of field work with a lot of fun! Special thanks to Filip Ånöstam for helping out!
Already after two years’ time a clear difference between the inside of the summer and winter exclosure can be visible!
Yesterday, we enjoyed the opportunity to present three talks during the special session on the ‘Ecology and Management of multispecies ungulate communities’ at the IUGB conference in Montpellier. We appreciated the chance to highlight first results of our research on Swedish ungulates, including diet compositions inferred from DNA metabarcoding and the linkages between environmental variables, population dynamics and browsing impacts. The session stimulated lively debate among the participating researchers, fostered new ideas, and will likely result in an extension of our current research collaborations.
On 13th of June, Beyond Moose organized a field excursion at Järnäs peninsula for Västerbotten’s wildlife delegation and moose management groups. We introduced the research program to a mixed public of foresters, hunters, land owners, politicians, and civil servants involved with the management of ungulate populations in Västerbotten. Under a lovely early June sun we discussed issues such as movement of moose and roe deer, monitoring of ungulate populations and their impacts on the landscape, and the links between ungulate diets, their impacts on the forest and competition among species. Here, the group is enjoying fika overlooking the Baltic.
Last week was another exciting week in the field! Even though the weather is not always on our side (like today with a thin layer of snow in Umeå) we were so far rather lucky and are hoping for the best in the coming days!
In one of our study areas in Southern Sweden, Öster Malma, we could already finish all of our field inventories. Besides counting dung groups of deer to estimate population densities we also measure the size of the single pellets to see if we can detect differences between the species. Especially distinguishing between roe deer and fallow deer in the field is mostly very tricky!
Further, our study area in Öster Malma contains 10 exclosure sites on clear cuts where we investigate the effects of seasonal browsing. For example several young trees are marked in these exclosures so that we can measure them every spring and autumn for the coming years.
Now we are hoping for the snow to melt to be able to continue soon with the dung counts in Nordmaling.
Lucky Friday! Today we captured our first roe deer, a young doe who might now just be the most northerly roe deer with a GPS collar in Europe. Unfortunately she did not pose for any pictures after the release.
Photo: F. Stenbacka
A new 30 or 60 credits MSc position entitled
Linking plant diversity to ungulate (klövdjur) diets or ecosystem productivity
is now available in Beyond Moose. We are looking for a candidate with good knowledge of the Swedish forest vegetation, including shrubs, forbs and graminoids in the understory. The full project description can be found here.