Nesting ecology and parental care of the Sabota Lark (Calendulauda sabota) in a savanna landscape in South Africa

Abstract

We report on the breeding biology of the Sabota Lark (Calendulauda sabota), a widespread and common but poorly known species. We present the results of data collected at 57 nests over 2 breeding seasons (2011–2013). Breeding coincided with the peak of the wet season in the study area and the breeding season appeared to be shorter in the study area compared to the rest of the species' range. Only females were observed constructing nests and laying and incubating started before the nest was completed, a strategy to reduce the overall nesting time. Nest quality varied considerably, including in the presence or absence of a dome and an apron. The mean clutch size was 2.5 ± 0.5 with incubation commencing upon clutch completion, performed by the female only and lasting 12.3 ± 0.5 d. Mean nest attendance during incubation was 74% and there was a steady increase in the duration of incubation on-bouts with progression of the incubation period. The mean nestling period lasted 11.7 d with both parents delivering food and both sexes performing brooding duties, a seemingly unique feature in the mirafrid clade of larks. There was evidence of subtle sex-specific roles during the nestling period with females primarily being responsible for brooding and males mainly provisioning. Breeding success using Mayfield's estimator was 33% with predation being the main cause of nest failure. Given the relatively poor breeding success, replacement broods were common but repeat-brooding attempts in a single season were rare with only 2 records during the course of this study. Although many of the reproductive features of Sabota Lark were similar to those of other larks, there were some differences and some apparently unique features that contribute to our knowledge of the Alaudidae.