Home range and movements of houbara bustards introduced in the Najd Pediplain in Saudi Arabia

Range sizes and movements of 29 houbara bustards (Chlamydotis[undulata]macqueenii) introduced in the fenced 2244 km2Mahazat as-Sayd Protected Area in south-central Saudi Arabia were studied in 1994 and 1995. Birds dispersed in all directions from a 4·0 km2release enclosure and cumulatively utilized an area of 3018 km2, mostly within the reserve. Home ranges of birds monitored for 8–24 months varied from 116 to 977 km2. All birds had distinct core areas of activity, ranging from 13 to 128 km2in size, within their home ranges. Differences in home range between individual birds were not related to sex. Estimates of home range size were positively correlated with the length of time that birds were monitored (i.e. free-ranging in the reserve). Sizes of seasonal home ranges varied substantially. Mean home range estimates for spring 1994 and spring 1995 were 123±103 km2and 242±166 km2, respectively; outside these periods, mean seasonal range estimates were ⩽50 km2. Movements of houbara increased following rainfall, apparently due to the effect of rain on the distribution of food. Average home range size decreased when food availability was reduced and patchy. Breeding birds and females with clutches utilized smaller areas during the spring and summer than non-breeders.