The biology of the Yellowthroated Sandgrouse Pterocles gutturalis in a South African agricultural landscape

A local population of Yellowthroated Sandgrouse was monitored from 1988-199 2 at Northam, Northern Province, South Africa, a region in which this speci es was previously an irruptive. non-breeding visitor. Yellowthroated Sandgr ouse were found to be veer-round residents, foraging and nesting exclusivel y in areas cleared for agriculture, particularly one-year fallow lands. The y ate the dry seeds of a variety of weedy plants. especially. Amaranthus an d Crotalaria spp.. Males outnumbered females 1.35:1. Egg-laying occurred fr om April October. with a peak in June. Clutch size (2-3) averaged 2.85 (n=2 6), and the incubation period for one nest was 26 days after clutch complet ion. Nesting success was estimated at 24.8% (n=19 nests. 176 nest days), an d the daily nest predation rate at 2.55%: predation and ploughing accounted Tur most nest losses. Average annual productivity was estimated to be with in the range 0.42-0.85 young/pair/year. We suggest that the Yellowthroated Sandgrouse depends on the sleds of early successional plants for food and t hat the recent agricultural development of the region maintains sufficient areas of fallow land to allow this otherwise nomadic species to become a br eeding resident.