Tawny owl survey: Public asked to listen for twit-twoos for 20 minutes a week

Appeal for help comes amid concern over bird's declining population

Researchers are urging members of the public to listen to tawny owls for 20 minutes a week and to pay special attention to their classic "twit-twoo" calls.

The British Trust for Ornithology are running a survey gathering information about the impact of urbanisation on the calling habits of the owls, amid concerns that the birds are in decline.

Participants in the survey are asked to listen for the birds in gardens, parks and woodland areas from 30 September 2018 to 31 March 2019, for one evening a week at any time between sunset and midnight.

Those taking part are asked to listen for the tawny owls calling to one another.

"The hooting or 'twoo' sound is usually made by the male and is a territorial call," researchers said in a statement on the trust's website.

"You can sometimes hear a female responding to a male’s 'twoo' call with a sharp 'kee-wick'."

The owls use the calls to attract a mate and then to reinforce a bond with them.

When the calls are in harmony the classic "twit-twoo" sound can be heard.

The trust also want to know how artificial light pollution and changing seasons affect the birds.

Participants do not have to take part every week or use the same location to listen.

They can submit their findings online or by post.

The survey is part of Project Owl, a five year scheme through which the trust will examine different breeding owl species.