Comparative Studies On the Reproductive Behaviour of Two Closely Related Weaver Bird Species (Ploceus Cucullatus and Ploceus Nigerrimus) and Their Races

Abstract

Abstract I. This paper provides quantitative data on the precise differences in breeding behaviour between two closely related weaver bird species, some of which function in reproductive isolation. 2. Ploceus cucullatus (7 races) and P. nigerrimus (2 races) have a wide broadly sympatric distribution in West, Central and East Africa south of the Sahara. P. nigerrimus is restricted to forest fringe and secondary growth around cultivation in forest lands while cucullatus, in addition to these, inhabits humid savannah and riverine areas in arid country. In one locality hybridisation has been reported. The races of each species are partially allopatric with interbreeding in zones of overlap. 3. The birds breed in crowded colonies and are polygamous, the males constructing up to five nests successively and acquiring a number of females. Each male defends a territory around his nest group. 4. Territorial behaviour in cucullatus consists of "supplants", "song bows" and "lunging matches" and the posturing is particularly static. In nigerrimus more mobile behaviour