Vol. 78 2026

ARTICLES

Pilot Study on the Breeding, Activity and Behaviour of the European Ground Squirrel Spermophilus citellus (Linnaeus, 1766) (Rodentia: Sciuridae) in Zoo Conditions

Katerina Zareva-Simeonova1,*, Yordan Koshev2, Maria Kachamakova2, Venislava Spasova3, Daniela Simeonovska-Nikolova3 & Krastio Dimitrov3

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*,1 Sofia Zoo, 1 Srebarna Str., 1407 Sofia, Bulgaria; E-mail: upupa1904@abv.bg
2Institute of Biodiversity and Ecosystem Research at Bulgarian Academy of Sciences, 2 Gagarin Street, 1113 Sofia, Bulgaria; E-mail: bgsouslik@gmail.com, maria.n.kachamakova@gmail.com
3Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tsankov Blvd., 1164 Sofia, Bulgaria; E-mail: v_spasova@biofac.uni-sofia.bg, dansim@biofac.uni-sofia.bg, k.dimitrov@biofac.uni-sofia.bg

https://doi.org/10.71424/azb78.4.003186

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Abstract

he European ground squirrel Spermophilus citellus is listed as “Endangered” on the IUCN Red List. Around the world, the species is bred in zoos to improve its conservation status. Until now, sousliks have not been bred in zoos in Bulgaria, despite this goal being included in the Action Plan for the Conservation of the European Ground Squirrel (Spermophilus citellus) in Bulgaria (2023-2031). We present the pilot activities for souslik husbandry at Sofia Zoo. Seven individuals were captured during a rescue operation in the area of Pazardzhik, within the Natura 2000 site “Reka Maritsa”. The animals were placed in the quarantine facility of Sofia Zoo. During the first week, their behaviour was recorded with video cameras. Two behavioural tests – the open field test and novel object exploration test were used to assess their locomotor and exploratory behaviour, as well as risk-taking in response to novelty, based on the recorded video. Two female sousliks were selected based on their behaviour to be kept in the Zoo’s exhibition area, while the others were released into а suitable habitat. The initial results show that the sousliks build nests from the provided hay and spend more time inside them. In the open field test, the sousliks spent significantly more time in the peripheral zone of the experimental arena than in the centre. In the novel object exploration test, only one female and one male approached the object and made contact with the object. The two individuals that remained in the exhibition enclosure showed an afternoon peak in activity during August, which corresponds to observations from other regions in Bulgaria. In conclusion, this is the first study to apply the open field and novel object exploration tests with S. citellus, and sousliks have been housed in captivity and displayed to the public in Bulgaria. This is an important step toward establishing captive breeding for conservation purposes.

Key words

husbandry, novel object exploration test, open field test, souslik

How to Cite
Zareva-Simeonova K., Koshev Y., Kachamakova M., Spasova V., Simeonovska-Nikolova D. & Dimitrov K. 2026. Pilot Study on the Breeding, Activity and Behaviour of the European Ground Squirrel Spermophilus citellus (Linnaeus, 1766) (Rodentia: Sciuridae) in Zoo Conditions. Acta zoologica bulgarica 78.

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