About Pterocles gutturalis A.Smith, 1836
This species, Pterocles gutturalis (yellow-throated sandgrouse), has long, pointed wings adapted for long-distance flight. Most of its body and legs are covered in feathers, which reduces heat gain via convection. Males and females are similar in size, with an average weight of 350 g (12 oz) and an approximate height of 30 cm (12 in). The two sexes differ noticeably in their plumage: males have brighter coloration, with black collars, lores, and underwing coverts, while females have paler, more cryptically colored plumage. Juvenile plumage resembles that of females, but has a finer mottling pattern. The two recognized subspecies also differ primarily in plumage: P. g. saturatior has brighter, cinnamon-colored upperwing-coverts.
Yellow-throated sandgrouse lives in open grasslands, farmlands, and the edges of arid areas. It favors clay-rich soils, and avoids coarser sandy or rocky soils formed from quartzite and granite.
The species has a disjunct distribution that follows arid corridors. The nominate subspecies P. g. gutturalis is found in Angola, southern Zambia, western Zimbabwe, Namibia, Botswana, and northern South Africa. P. g. saturatior occurs from Tanzania to northern Zambia, and across southern Ethiopia through Kenya. P. g. saturatior is mostly sedentary. South African populations of the nominate subspecies are also sedentary, while populations in Namibia and Botswana are migratory; overall, P. g. gutturalis is mostly migratory, as regional flood patterns force the birds to move.
The breeding season for this species runs from March to October. While courtship behavior has been recorded in pairs of P. g. gutturalis, written descriptions of these rituals are scarce and inconsistent compared to what is known for other sandgrouse species. To build their nest, a breeding pair scrapes out a depression in the soil, then lines it with dry weed stems or dry grass. When vegetation cover is available, pairs will choose a nest spot next to this cover. Nests from different pairs can be found 40 to 45 meters apart in the same open field. Eggs of this species are relatively small, which lowers parental energy investment and shortens the combined laying and incubation period, which totals approximately 30 days. Eggshells have a reduced pore area that limits water loss in arid environments. The mean clutch size is 2.85 eggs, and average annual productivity is estimated at 0.42 to 0.85 young per breeding pair.
