abstract |
In Ukraine, the most suitable territory for rewilding projects and the restoration of self-regulated landscapes with participation of large ungulates including Przewalski’s horse (PH) is the Chornobyl Biosphere Reserve (ChBR). Studies of the PH in ChBR are also important for this is one of the few populations living in the wild for several generation without human support, gradually increasing its abundance and area of distribution. In 2025, up to 200 PHs lived in the ChBR, and up to 50 more in the territory of the neighbouring Polissky State Radioecological Reserve of Belarus. The social structure of PHs in the ChBR in 2021–2025 included: 1.7–2.4% single individuals, 4.2–7.9% pairs and triads, 72.2–79.3% harem herds, and 14.8–16.8% bachelor groups. PHs have stable yearly reproduction, foals making up 17.8–18.2% of the total population. The average size of the harem herd is 8.7 individuals (stallion, 5.4 mares, and 2.5 foals). Harems have their own territories, which are marked and guarded by the stallions. The structure and composition of the harems are rather stable. The bachelor groups are least stable, and they are the least studied because of their very careful behaviour. In 2018, a domestic mare joined one PH harem herd and since it has participated in breeding, causing a problem of hybridisation. In 2025, several individuals had already clear signs of hybrids. This situation requires urgent response measures in order to preserve the genetic purity of the species. Also, since the individuals that are not part of harems normally tend to spread, leaving the ChBR and dying beyond its area, it would be worth capturing them opportunely and return back to the ChBR. Within the PH population, some herds and individuals still display calm behaviour towards humans, indicating an incomplete rewilding of the species. However, in most cases PHs avoid contacts with humans and display a clear anti-predatory behaviour. In general, being a steppe species, PHs in Central Polissia show signs of adaptation to living in forest ecosystems. Monitoring with visual recording of PHs can be recommended as an additional measure, in particular by the reserve’s protection service. The Action Plan for the Management of the Chernobyl Horse Population should include measures to overcome inbreeding and control hybridisation with domestic horses. |
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