Pattern of damage to early and late maize in southwestern Nigeria by the village weaverbird(Ploceus cucullatus)

Abstract

Abstract Village weaverbirds (Ploceus cucullatus Muller) normally feed on early maize in the morning (0800 to 1100 h) and evening (1600 to 1800 h) in southwestern Nigeria. However, when disturbed the birds feed during all the hours of daylight, and to be effective bird scaring would have to persist throughout the day. Developing grains are eaten, but rarely dry grains. The period of active bird scaring can therefore be reduced to about two weeks. In 1977 the mean percentage damage varied from 2.2 ± 0.3% in plots with dry ears to 34.1 ± 12.7% in plots with fresh ears, but in 1978 the situation was reversed with 17.7 ± 3.1% damage in plots with dry ears to 1.1 ± 0.2% in plots with fresh ears. The pattern of damage to early maize is associated with the annual rainfall, which determines the occurrence of lepidopterous larvae and wild sorghum (Sorghum arundicearum Stapf) which form alternative food items for the birds. Less than 2% of late maize ears was damaged since alternative food resources were abundant. ...