During January-March 2007 we studied nesting behaviour and chick development in the Peruvian endemic Black-necked Woodpecker Colaptes atricollis in an agricultural area near Ica, on the south coast of Peru. Birds were observed in a semi-natural habitat with a rich variety of fruit-bearing trees and shrubs, including both native and introduced species such as Spondias purpurea, Persea americana, Carya illinoensis, Annona cherimolia, A. muricata, Psidium guajava, Inga feuillei, Mangifera indica, Vitis vinifera and Citrus sp. Mixed with these domesticated species are native trees such as Prosopis limensis, Acacia macracantha and Tecoma fulva. These species grow at the borders of irrigated sunken fields (<1 ha) with small crops of cotton Gossypium barbadense, maize Zea mays and lima beans Phaseolus lunatus, amongst others. We observed four pairs of Blacknecked Woodpeckers, of which one was monitored using photography as it nested successfully in the trunk of an avocado Persea americana tree. The reproductive period lasted c.42 days, with 14 days incubation and 28 days until the chicks fledged. Both adults fed and incubated the chicks. In the same area in June-July a pair of woodpeckers produced a clutch of four eggs in the same nest, from which just one young fledged. In another area of natural habitat, at the dry edge of a ravine, we observed a nest with two chicks in December. Our data concerning chick development are the first for the species, and we also demonstrate the importance of fruit trees in agricultural areas for Black-necked Woodpeckers to nest, especially when native trees have been lost due to deforestation. However, the species can also use the terraces in dry riverbanks instead of trees.