Life history traits associated with low annual fecundity in a central African Parid : the Stripe-breasted Tit Parus fasciiventer

Abstract

Most Parus species live in the tropics or sub-tropics, and are likely to show life history traits associated with relatively high survival and low fecundity. Based on a 15-year study, we provide the first detailed account of the life history traits of an equatorial Parid, the Stripe-breasted Tit P. fasciiventer, which we contrast with published accounts of north temperate races of the Great Tit P. major. Stripe-breasted Tits fledged a mean of just 1.62 offspring clutch−1, but laid up to four clutches year−1 (mean 1.72) over 11 calendar months, raising their mean annual fecundity to 3.09 fledglings female−1, less than half that of European Great Tits but double that of single-brooded southern African congeners. During incubation, Stripe-breasted and Great Tit females showed similar levels of nest attentiveness, spending 84 and 83–86 % of each 24-h period on the nest, respectively. In contrast, Stripe-breasted Tit parents provisioned at just 10–18 % of the rates recorded for European Great Tits, suggesting that parental investment or prey availability in their respective habitats differed to a similar degree. Consequently, Stripe-breasted Tit nestlings grew more slowly, remained in the nest 4.6 days (20 %) longer, but fledged with proportionately longer wings, perhaps improving their ability to avoid predation. Offspring were last recorded receiving parental care at a mean of 81 days post-fledging (four times longer than is typical of European Great Tits) and remained with their parents for up to 3 years. Helpers were recorded at 61 % of Stripe-breasted Tit nests, and 76 % of breeding adults had helpers during at least one breeding attempt. While latitudinal comparisons often focus on clutch size, much greater disparities were thus evident in other traits, including brood provisioning, the duration of post-fledging care and the incidence of cooperative breeding.