House sparrows can be seen around their nest sites in almost any month of the year, though attendance is at its lowest in late summer and early autumn. Attendance remains low through the winter, increasing as days lengthen and the temperature rises. Most nests are under the caves of houses, or in some other cavity in a building. Some are in haystacks and more natural sites such as crevices in cliffs or in thorny or dense shrubs like hawthorn. Usually, several pairs build nests in a loose colony.br The song of a territorial male house sparrow is a monotonous, repetitive ‘chirrup’, a familiar noise chosen site, often adopting a squat, fluffed-up posture.