Diet and sexual segregation of desert bighorn sheep (Ovis canadensis mexicana Merriam) in Sonora, Mexico

Abstract

Objective: To determine the diet of the desert bighorn sheep and to identify differences in its composition between sexes during the reproductive and sexual segregation periods.

Design/methodology/approach: The study was carried in the UMA Rancho Noche Buena, Hermosillo, Sonora. The microhistological technique and a cell catalog of plants from the study area were used to identify plant species present in fecal samples of bighorn sheep. The relative frequency, the Shannon-Weaver diversity index and the Kulczynski similarity index were determined by sex and period (reproductive and segregation)

Results: The diet of bighorn sheep included 40 species, being herbaceous (36.1 ±4.4 %) and grasses (26.8 ±8.9 %) the most common. The diet of males during the segregation period was mainly composed of grasses (36.2%) and female diet by herbaceous (30%) and grasses (29.8%). No differences were found in the diversity of the diet of males and females in the segregation period (H '= 1.0) and in general, their diets were very similar (80%).

Limitations/implications: To collect a greater number of fecal samples by sex and period (reproductive and segregation) and to analyze the nutritional content of plants consumed by bighorn sheep.

Findings/conclusions: In this study, the sexual segregation exhibited by the bighorn sheep in the Wildlife Management and Conservation Unit Rancho Noche Buena was not due to food preferences.