This is the first study on spatial behaviour of brown hares Lepus europaeus Pallas, 1778 based on radio-telemetry in a natural system, which we contrast with data from agricultural systems. Radio tracking took place in a Dutch salt marsh over a 10-month period, with intensive tracking sessions during April/May and December/January. Six hares could be followed in both periods and in total 1224 fixes were collected. Average home range size was calculated as 28.7 ± 8.5 ha when using Adaptive Kernell method (Mimimum Convex Polygon: 27.3 ± 9.0 ha) on 90␘f all fixes. Such values are in the lower end of the range of those obtained for agricultural systems. Home range size did not differ between sexes, day and night, or across seasons. However, the size of the core range (50␘f fixes) was twice as large in May compared to the winter period, and thus inversely related to food availability. Unlike in agricultural systems, use of space by hares did not change over the course of the season. This probably reflects the patchy nature of the natural habitat which provides food and shelter throughout the year in a confined area.