Aspects of the breeding biology of the Arrowmarked Babbler Turdoides jardineii in South Africa

The breeding success of 18 groups of Arrowmarked Babblers Turdoides jardineii was followed in the 1992–1993 breeding season. The first eggs were laid in late October 1992 and the last eggs in February 1993. Group size was positively correlated with territory size. However, neither group size nor territory size was correlated with the number of offspring raised by a group. Extra adults in a group may not have enhanced the reproductive output of the breeding pair, but they helped in the defence and enlargement of a territory in a saturated habitat.