Tune your ears in to the twit-twoo of tawny owls

PEOPLE are being urged to spend time listening out for the “twit-twoo” of tawny owls to help monitor how the birds are faring.

Tawny owl numbers are thought to have declined over the past few decades and they have recently been added to the “amber” list of birds of conservation concern.

The British Trust for Ornithology (BTO) is concerned that the species may be vanishing from towns and cities.

But the birds are difficult to monitor as they are nocturnal, so the trust is running a tawny owl calling survey to monitor their presence through the sound of their calls.

Members of the public are being encouraged to spend 20 minutes on one evening a week listening out in parks, gardens and woods for the distinctive “hoot” calls of the males and the “kee-wick” of the females.

Together the two owls calling in harmony make the kewick-whoo or twit-twoo sound for which the tawny is known.

Even if people do not hear an owl, the researchers say that is still important information, as it indicates where the species is missing.

Claire Boothby, tawny owl calling survey organiser at the BTO, said: “Getting involved couldn’t be simpler – just wrap up warm and give yourself 20 minutes to listen for the haunting calls of tawny owls between now and the end of March.

“You can listen from your garden, local wood or park, or even from the comfort of the sofa with your window open, and tell us whether or not you hear an owl.

“Don’t worry if you don’t hear one in your 20 minutes – that record is just as valuable and you’ll become one of our ‘zero heroes’.”

Nearly 6,000 volunteers have already reported what they have heard as part of the survey but the BTO would like at least 10,000 people across the UK to take part in the “citizen science” research.

The survey comes as the BTO reviews 2018 for bird life, reporting on a range of research projects. A spokesman said the organisation’s scientists had been “leading on, or contributing to, a number of highimpact publications.”

He went on: “March saw the publi- cation of the results of the 2014 Peregrine Survey. This gave a population estimate of 1,769 breeding pairs for the UK, an increase of 22 per cent on the previous survey in 2002.

Most of the increase was due to population growth in lowland England, with pairs occupying new sites, including man-made structures.

“In June, the results of our latest Nightingale Survey were published, producing an estimate of 5,094-5,938 territorial males.

The study highlighted the national importance of Lodge Hill in Kent, part of which is designated as a Site of Special Scientific Interest (SSSI) for Nightingales. Five thousand new homes were proposed at Lodge Hill, but in December 2018, it was announced that only 500 homes would now be built, and none will be located on the SSSI.

“We also published our first peerreviewed paper using data collected as part of our What’s Under Your Feet project in 2018; 15,000 school children dug up their playing fields in October, March and June of each academic year, helping us to show that dry summer weather may be putting some of our favourite bird species at risk as it triggers a significant drop in the availability of earthworms close to the soil surface during the breeding season.

“Other BTO-led research in 2018 showed how breeding waders are benefitting from agri-environment schemes in Europe, and how data collected by volunteers taking part in the Breeding Bird Survey (BBS) are revealing changes in the patterns of abundance for nine mammal species.

“Perhaps the biggest science story of the year came in September, from research showing that pecking order at garden bird feeders is determined by size and weight.

“House Sparrows and Greenfinches were found to monopolise food, while smaller species, such as Blue Tit and Coal Tit, had to make flying visits and make do with poorer quality food.”