Behaviour This migratory species is extremely gregarious, and typically nests in chimneys, though other structures such as hollow tree trunks can be used1,3. Eggs have been recorded from May to July, though the precise timing varies slightly throughout its range. A clutch of two to seven eggs is laid, and extra-parental co-operation is well established. It is present in North America until September1. Habitat It is readily associated with urban settings, though also forages and breeds over a variety of natural habitats over its wide range. Main habitats include river-edge forest, the edge of tropical lowland evergreen forest and second-growth scrub. It can also be found along the coast in Peru, up to 3,000 m over irrigated farmland in western Andean valleys, and even in central city zones1. Diet Spiders, along with Hymenoptera spp., Diptera spp. and other insects have been recorded1.