Managed pine plantations now constitute a large portion of mainland New Zealand. Despite many native birds inhabiting these exotic habitats, their value for biodiversity conservation is unclear. Although numerous studies have quantified densities of native bird species in pine plantations, it is unknown whether these individuals constitute self-sustaining populations. Here we address this question for North Island robins (Petroica longipes) in a Pinus radiata plantation in the central North Island.
Intraspecific foster feeding and adoption has rarely been observed in birds, with the exception of waterfowl. In this study, I document for the first time the existence of intraspecific foster feeding and adoption of fledglings by adult passerines with their own young. During a three-year study of the North Island robin (Petroica longipes), a species with very low levels of extra-pair paternity, eight fledglings (4% of the fledglings in the population the study years) were fed by adults other than their parents, with four of these being adopted.