Mineral Lick Use and Movement in a Remnant Desert Bighorn Sheep Population

Abstract

Following a precipitous decline from approximately 150 animals in the 1950's, bighorn sheep (Ovis canadensis mexicana) in the Big Hatchet Mountains of southwestern New Mexico had failed to increase beyond 20-25 sheep. Monitoring of this herd from June 1976 to May 1978 revealed an unusual trans-desert movement pattern which resulted in the disappearance of young lambs (Lenarz 1979). Sheep apparently left the mountain range to use sodium-rich mineral licks (Watts 1979). Our paper examines the relationships between this movement pattern, possible recurring sodium deficiencies in the sheep, and associated lamb mortalities.