Distribution of Spermophilus citellus in the Komárom-Esztergom County, Hungary, in 1950-2019 (Rodentia: Sciuridae).

The study describes changes in the Hungarian population of the European ground squirrel (Spermophilus citellus) that occurred between 1950 and 2019. Data before 1990 were collected from local communities who were familiar with this mammal (an example of citizen science). The comparison was based on the area occupied by the animals. The studied region was in the Komárom-Esztergom County, north-western Hungary, where the species was widespread in the middle of the 20th century. It was common in the lowlands, low hilly country and even in suitable habitats in uplands. By 1990 the population had drastically declined, to about 1.5% of the previous levels, and today 99.7% of the population has disappeared with only small, vulnerable populations surviving. [ABSTRACT FROM AUTHOR]