Objectives:

1- To determine the frequency of utilization of water sources by the bighorn sheep at El Plomito, Sonora.

2- To determine the use of water sources by the different age-classes of bighorn sheep at El Plomito, Sonora.

In Mexico, the desert bighorn sheep is a species with a high cinegetic value, historically distributed in Chihuahua, Coahuila, Nuevo León, Sonora, Baja California and Baja California Sur. However, due to habitat destruction, the introduction of domestic cattle and illegal hunting, it was erradicated from most of its original range. The present study was made during the hot-humid (July to September) and cold-dry (October to December) seasons of 2000.

This study consisted in field observations to determine the amount of feeding upon two agave species, Agave zebra and A. pelona, and the use of automatic camera to determine the use of water sources by the sheep. Sheep consumed 18 agaves, favoring A. zebra (12 of 18) of 98.7 cm of average diameter. It was found that in the study area the main density of agaves was 2,825 individuals per hectare. Bighorn sheep at El Plomito didn’t use the water source within their area. These results confirm those of Tarango (2000), who said that the bighorn sheep at El Plomito depend only on succulents to meet its water requirements.