Objectives:

1- To describe and quantify the sexual segregation phenomenon of a native desert bighorn sheep population at El Plomito, Sonora.

2- To test three potential hypothesis that may explain sexual segregation in ungulates.

3- To determine the habitat use of the bighorn sheep at El Plomito, Son.

4- To analyze the annual dietary composition of adult females, adult males and mixed groups of bighorn sheep.

5- To determine the quality of vegetation that is part of the bighorn sheep´s diet.

6- To compare the habitat use, dietary quality and composition information between adult females, adult males and mixed groups of desert bighorn sheep.

Because of all this, the species is being treated under special protection.
The present study contributed to a better understanding of sexual segregation among ungulates and obtained important information that may help a better management of the bighorn sheep in a national basis.

This study involved a field part of two years (1997-1998) and was focused on habitat use data collection, like recovery of scats (for dietary composition), collection of plants (bromatologic analysis) consumed seasonally by males and females.

It is predicted that the groups of females tend to use more steep walls, closer to escape areas and with better visibility than those areas favored by males. If males and females use different areas, it is suspected that there may be strong differences in their dietary composition. It is expected also that the nutritional quality of the male’s diet would be higher than that of the females.