Activity rhythms of houbara bustards (Chlamydotis undulata macqueenii) in relation to some abiotic factors

Activity rhythms of captive-bred reintroduced houbara bustards (Chlamydotis undulata macqueenii) were studied in the Mahazat as-Sayd reserve in Saudi Arabia. Birds were radio tagged with solar powered transmitters and activity was recorded with an automatic recording station over several weeks in the summer of 1993. Peaks of diurnal activity were observed at dawn and dusk. Daytime activity was negatively related to solar radiation and soil surface temperature. Nocturnal activity was triggered by moonlight. Food consumption, the duration of night-time activity and the minimum distance moved at night by houbara were positively correlated to the duration of moonlight.