Between himself and project partner Adrienne Stratford, they have colour-ringed more than 4000 pulli as well as about 120 adult Chough, with over 20,000 resightings of colour-ringed individuals during that time.
“When we started the project, it was widely thought that the inland and coastal populations were completely separate, but we now know that they are part of the same population. It is apparent that they need good foraging habitats to be maintained in both coastal and inland mountain areas, as the same birds use both areas at different times of year and stages of their lives, with a lot of youngsters from all areas gathering into “youth-club” flocks in the mountains during their first and second autumns.”
Individual colour marking has allowed Tony and Adrienne to build an intricate picture of the birds’ social lives, breeding biology, movements and land use preferences. Currently, the oldest breeding Chough is 17 years old. In 2004, a flock of about 12 birds left Anglesey and went to the Isle of Man, three of these birds subsequently came back to the mainland, of which two are now part of the Anglesey breeding population.
During the intervening years, they have charted the fortunes of this iconic bird, its disappearance from most of inland mid-Wales, increases in some coastal areas, and recently, worrying signs of decline in inland Snowdonia, probably linked to reduction in grazing of upland pastures due to changes in agricultural subsidies.