Churring
Producing a continuous deep trill. The best example to be heard in the British Isles is the song of the Nightjar Caprimulgus europaeus, which can be sustained for up to five minutes without a break, but many other species have churring call notes, for example the Mistle Thrush Turdus viscivorus.From Peter Weaver's Birdwatcher's Dictionary
Copyright © 1981 by Peter Weaver