Resumo

ROMAN-VALDEZ, Raúl et al. Population structure of Ovis canadensis weemsi Goldman, 1937 in the El Carmen Island, Southern Baja California. Rev. mex. de cienc. forestales [online]. 2016, vol.7, n.34, pp.69-84. ISSN 2007-1132.

In Southern Baja California the populations of desert bighorn sheep (Ovis canadensis) have diminished, mainly as a result of the fragmentation of their habitat and of furtive hunting. It is a species with a restricted spatial distribution because it requires its habitat to have certain specific characteristics so as to be provided with water, food, cover and space-all of which are determinants for the selection of distribution facts. O. c weemsi ha the status of Species “Subject to Special Protection”, and currently only registered in some areas of Sonora, Baja California and Baja California Sur. The El Carmen island belongs to the Parque Marino Nacional Bahía de Loreto which, due to its geographic location, climatic conditions, water scarcity, types of vegetation and topography, is an extremely interesting site in which to carry out research in arid ecosystems. The distribution of the bighorn sheep introduced into the island was determined using the strip count method modified by Hayne and through records of specimen sightings at the drinking troughs, as a way of reinforcing the observations on the population structure of the species. Furthermore, the data on the land slope, time of the year, distribution of the drinking troughs and presence of feeding troughs were collected in order to determine their effect on the population structure. The results indicate a population density of 4.96 sheep km-2, with a total of 1 151 observations. The total number of individuals was estimated to be 616, on a surface of 12 428 ha with sarcocaulescent desert shrubs.

Palavras-chave : Bighorn sheep; strip count; population density; population structure; Hayne’s method; Ovis canadensis weemsi Goldman; 1937.

        · resumo em Espanhol     · texto em Espanhol | Inglês     · Espanhol ( pdf )