Territoriality of Cape Sugarbirds (Promerops cafer) between and within breeding seasons

Abstract

Cape Sugarbirds are southern African endemics, found in fynbos vegetation of the Western and Eastern Cape Provinces of South Africa, and they feed almost exclusively on the nectar of Protea inflorescences. Breeding male Sugarbirds are highly territorial and defend resources for themselves, their mates and their offspring. Sugarbirds, however, often leave their breeding territories in search of food during the dry season and return to the same breeding sites each year, thus experiencing an annual cycle of movement from one food source to another. Male territory size as well as breeding success, were determined over two breeding seasons for a population in the Helderberg Nature Reserve in the Western Cape Province. Sugarbird fledgling success was significantly greater for males defending large territories. Males moved or increased the size of their territories between seasons, possibly to improve breeding success, but no changes in territory size were observed during the breeding season.