Recovery of an isolated badger (Meles meles) population in The Netherlands

South of the town of Hilversum, The Netherlands, remained a small isolated population of badgers in 1983. Improved protection and, possibly, a few reintroductions made this population grow steadily in the following four decades. The number of occupied main setts grew from a only 5 setts in the 1980s to 137 in 2021 and the number of badgers from a dozen to 500. The proportion of occupied main setts where badgers reproduced, increased significantly (P < 0.05) from circa 30% in the earlier years to 45% in later years. The observed litter size based on emerged cubs was 2.26 without a change over time. The average density-related apparent mortality was 14–26%, depending on underlying assumptions. The estimated size of territories, based on dispersion distances, was 50–150 hectares. The observed number of badgers per main sett tended to increase (P < 0.10) from circa 2.7 during the first decade to circa 3.7 in the end. The increase of the total number of badgers in the region was, however, mainly associated with a proportional increase of the area where badgers and their setts can be found nowadays. This expansion continues until the present day, albeit at a diminishing pace.