Tahere Musavi

Chukar (Alectoris chukar) and see-see partridge (Ammoperdix griseogularis) are distributed almost in all mountainous areas of Iran. Despite high recreational and economic value of these two bird species, very few studies have been done on their ecology to assist in their management and conservation. We studied habitat selection and segregation by these two species in Kaeeze No Hunting Area, Boushehr province, southern Iran. Four vegetation types were recognized in the study area. The presence of each species was recorded by traversing transects (total length = 35 kilometer) randomly located in each vegetation type. Absence points were also recorded where no sign of either chukar or see see partridge were present. Microhabitat variables including percent cover of plant species, percent cover of scree, percent cover of rock, and substrate temperature were measured in 5´5 plots centered on presence and absence points. Topographical variables were obtained from a digital elevation map and distance from roads and developed areas were extracted from landuse map using ARC GIS software. Logestic Regression was used to model the relationship of each species presence/absence with the environmental variables in two distinct warm and cold seasons. In cold season probability of chukar presence increased with incrasing percent cover of herbs and litter, while in warm season tree crown cover, herb and substrate temperature were the best predictors for the presence of the species. For see-see partridge percent cover of herbs and stone were retained in the model of cold season, and percent cover of herbs, shrub and tree crown cover were the most important predictors for the warm season. Mann-Whitney nonparametric test showed significant differences in habitat variables (elevation, slope, sine and cosine of aspect, distance to developed areas, percent covers of rock, scree, stone and vegetation) between the two species, Principal component analysis separated the two species based on their associations with the environmental variables. Elevation recognized as the most important parameter separating the niche of the two species. See-see partridges occupied elevations up to 700 meters while chukars exist in rocky substrates from 700 to 1600 meters. We collected the bird's crops from hunted chukars and see-see partridges in summer to compare the diet of the two species. We identified 17 and 23 items consumed by chukar and see-see partridge respectively. Niche breadth of see-see partridge was larger than that of chukar.The dietary overlap between the two species was 50% calculated using Pianka's niche overlap equation. Safflower was the most frequently observed food item in crops of chukars (18 out of 22) and see-see partridges (28 out of 31). Other food items consumed by chukar were bulbs of Gagea sp., wild barley, and ants, while seeds of plant species of the families Compositae and Graminae were more frequenly used by see-see partridges.