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Monitoring the conservation status of wolves in Slovenia in the 2020-2021 season

30 March 2022
Slovenia Forest Service

During the last wolf monitoring season, 12 wolf packs were detected in Slovenia. We estimated the size of the super-population, which includes Slovenia and the border area of Croatia, at 138 wolves (121-168; 95% confidence interval). The estimate for the number of wolves in Slovenia is 120 animals (106-147; 95% confidence interval). We estimate that the wolf population in Slovenia has been increasing since 2010.

Monitoring the conservation status of wolves in Slovenia in the 2020-2021 season - Life Wolfalps EU
Multi-annual dynamics of the wolf population in Slovenia. Prepared by Tomaž Skrbinšek

Monitoring of wolves in the 2020/2021 season followed the established practices of previous years, with two major changes;  a) the project partnership was expanded and the public institution Triglav National Park has been involved in the implementation of the activities, alongside the Slovenia Forest Service (ZGS), the Biotechnical Faculty at the University of Ljubljana and the NGO Dinaricum, b) and the wolf census with howling method was postponed from the beginning of the season to the end of the season. At the same time, we extended the census area to the NW part of the country. Up-to-date information on distribution was also obtained through data on the damage caused by wolves to grazing animals. We recorded all perceived wolf mortalities and collected tissue samples from dead animals for genetic identification of individuals. The collection and analysis of non-invasive genetic samples and the census of territorial wolves through howling remains the main methods that give us insight into the status and evolution of the population. Both of these core monitoring-methods would not have been possible without the efforts of many volunteers – including hunters. This season, more than 100 people took part in the collection of non-invasive genetic samples, and over 300 volunteers took part in the territorial wolf census. Many members of hunting families also took part in both activities.

Monitoring the conservation status of wolves in Slovenia in the 2020-2021 season - Life Wolfalps EU
The grid of quadrants where the wolf howling took place in 2021, the recorded wolf responses and the locations where we confirmed with a photo the presence of wolf litters. Prepared by Gregor Simčič

The collection of non-invasive genetic samples, i.e. feces, urine, hair and other genetic material that animals continuously leave in the environment, took place between May 1, 2020 and April 30, 2021. During this period, we managed to collect 470 samples, mostly feces. In addition to these samples collected for the purpose of targeted monitoring, saliva samples from bite wounds of grazing animals collected by the SFS as a public service, samples collected from wolf radio-collaring in the framework of the LIFE WolfAlps EU project were included in the final analyses. Taking into account all the sources of samples, we managed to collect over 700 samples in the 2020/2021 season.

As is normal for projects of this kind, laboratory analyses reveal that not all the samples collected are fresh enough for genetic identification of the animal or do not belong to the target species – the wolf. Nevertheless, all the effort put into collecting the samples was worth it, as 66% or 316 of the samples collected were working and belonged to wolves.

How many wolf packs are there?

In addition to abundance estimates, genetic surveys can be used to monitor the spatial distribution of wolves to estimate territory ranges and the number of wolf packs. For the 2020/2021 season, we have confirmed 12 wolf packs by analyzing wolf pedigrees, two of which have part of their territory in Croatia.

Monitoring the conservation status of wolves in Slovenia in the 2020-2021 season - Life Wolfalps EU
Approximate spatial distribution of wolf territories in the 2020/2021 season. Prepared by Gregor Simčič; Data: Tomaž Skrbinšek

In addition to wolf packs that are families (parents and their offspring), the population also consists of lone wolves. These are mainly dispersers – animals that have left the area of their natal pack in search of a sexual partner and to establish their own territory, and migrants – the name given to dispersing wolves that come to us from unknown packs (e.g. Croatia, Italy, Bosnia and Herzegovina). This season we detected 18 wolves outside the territories of confirmed packs, 10 of which were dispersers from known packs and 8 migrants.

For a more detailed presentation of the results of the last wolf monitoring season, we invite you to read the full report, which is publicly available online (, Publications).