Seasonal use of salt blocks by mountain hares in Sweden

Salt blocks placed afield by Swedish hunters for wild ungulates also are used by mountain hares (Lepus timidus). However, little is known about the seasonal patterns of salt use by hares, a fundamental consideration regarding the potential benefit of this mineral appetite. Thus, we monitored the use of salt- block (NaCl) stations by mountain hares at the Grimso Wildlife Research Station, Riddarhyttan, Sweden from April 1988 to june 1989. Use of the stations peaked between April and july, declined to a low in january, and then rose again to the April-july peak. We suggest that this use reflects an appetite for sodium (Na) that may result from the ingestion of plant secondary compounds, a seasonal excess of dietary potassium, and/or the nutrient demands of growth and reproduction