Distribution of the harvest mouse (Micromys minutus) in Georgia based on barn owl (Tyto alba) pellet analysis

The present study investigates the distribution of the harvest mouse (Micromys minutus) in Georgia through the analysis of barn owl (Tyto alba) pellets. Historically, Micromys minutus has been documented in restricted areas of western Georgia, with a fragmented range that extends into north-eastern Azerbaijan. Despite being considered nationally vulnerable, its current status and distribution within Georgia remain insufficiently known. With the recent establishment of the barn owl as a breeding species in Georgia, this study explores the potential of diet analysis as an effective method for detecting elusive or poorly documented small mammal species. Pellet collection was carried out between June 2023 and January 2025 across diverse Georgian regions, including Adjara, Guria, Imereti, Kakheti, Kvemo Kartli, Mtskheta-Mtianeti, Samegrelo-Zemo Svaneti, and Shida Kartli. Nevertheless, remains of the harvest mouse were only recovered from pellets collected in Adjara, Imereti, Kakheti, Kvemo Kartli, and Samegrelo-Zemo Svaneti. All collected pellets were processed using standard osteological techniques, and prey species were identified based primarily on cranial and mandibular remains. A total of 6136 prey items were identified, among which 82 individuals (1.34%) were assigned to Micromys minutus. The species was most prevalent in Samegrelo-Zemo Svaneti (64 individuals, 16.45% of prey), followed by Adjara (9 individuals, 2.99%) and Imereti (5 individuals, 13.51%). In eastern Georgia, the species was recorded in significantly lower numbers, with only one specimen from Kakheti (0.03%) and three from Kvemo Kartli (0.16%), confirming its rarity in that part of the country. These findings reveal a broader and more continuous distribution of Micromys minutus in western Georgia, while suggesting scattered populations further east. The results support earlier hypotheses regarding importance of barn owl dietary studies in small mammal biodiversity assessment. This study provides essential baseline data for conservation efforts and long-term monitoring of this ecologically valuable but vulnerable rodent species.