A less-than-annual breeding cycle in a pair of African bat hawks Macheiramphus alcinus

An urban-nesting pair of African bat hawks Machaeramphus alcinus in Zimbabwe laid regularly every 10-11 months over six breeding seasons, with the egg being laid at least 1 month earlier each successive year. This less-than-annual cycle was probably due to a stable and regular food supply of insectivorous bats that were attracted to lights when feeding and could be caught all night at all times of the year. Therefore, the bat hawks could breed as often as their body condition allowed.This cycle differs from the known situation in rural bat hawks which lay annually mainly during September and October. These probably take advantage of easily-caught pregnant female bats in September/October in order to attain breeding condition, whereas fledgling bat hawks take advantage of recently independent but naive juvenile bats in January/February. The relative dearth of bats in rural areas outside this period may account for the regular annual breeding of bat hawks at the time of greatest prey availability.