A slow-winged display flight with occasional wing beats and wing-clapping. The nest is a roughly lined scrape hidden among grass heather, marram, or dead reeds. The 4 to 8 white eggs, though up to 14 in years when voles are plentiful, are laid in late April or early May at 2-day intervals. Incubation, by the female alone, commences with the first egg and lasts 24 to 28 days. The young leave the nest after 12 to 17 days and fly after 24 to 27 days. One brood is usual, though in years of vole abundance, two broods may be attempted.
Open grassy moorland, marshes, sand dunes; in winter frequents grassy marshes and grazing meadows, also adjacent arable fields and moors.
The under-wing is whitish with blackish tips and a dark carpal mark; flight soft and wavering with slow, deep wing beats; quarters the ground low, often hovers; on breeding territory Buzzard-like circling; display flight includes wing-clapping.
Some information extracted from the World Owl Trust www.owls.org