The diet and nutrition of the Namaqua sandgrouse, an arid-zone granivore

Abstract

The diet of the Namaqua sandgrouse, Pterocles namaqua, is described, and daily seed intake needed to meet limiting nutrient requirements during different stages of the annual cycle is estimated. Namaqua sandgrouse feed almost exclusively on seeds, mainly on those of protein-rich legumes. The energy content (17–24 kJ g−1) of selected seed species is less variable than protein (10–37%) and amino acid (0·11–4·52%) content. Energy is usually the first limiting factor for adults, especially females producing eggs. Essential amino acids appear to be more limiting than energy for growing chicks, suggesting that chicks may be more dependent on protein-rich legume seeds than adults. The dietary requirements for essential amino acids in developing chicks are similar to those of females producing eggs, suggesting that chick development is the most nutritionally demanding stage in the annual cycle of Namaqua sandgrouse.