Staff and volunteers at RSPB Bempton Cliffs have been carrying out vital work to combat the decline of the humble tree sparrow, which was once a regular sighting in gardens across the country.
Since the late 1970s, the population of tree sparrows has plummeted, and - despite a recent increase - the current number still stands at less than 10 per cent of that of the late sixties and the birds are listed as 'red status' in the RSPB's conservation rating. The dramatic crash in population size can be attributed to a number of issues: hedgerow clearance, intensive farming, loss of old trees and converting old farm buildings into homes.
It is important, now more than ever, that the health of tree sparrow colonies is monitored. Ringing is a vital tool when it comes to investigating population declines; it provides conservationists with vital data such as movement, how long the birds live for, changes in population, how faithful they are to a site and much more. Over time, this data will help conservationists draw conclusions that may help the population get back to where it was decades ago.
Dave Aitken, Bempton Cliffs' Warden, said: "We've been ringing our colony of tree sparrows here at Bempton Cliffs over the last few weeks. Despite their size, these tiny birds are able to be ringed when the youngster is just 7-9 days old. Once in place, it has no effect on the bird's movements - it's a bit like us carrying a mobile phone around."
To date this season, 116 juvenile tree sparrows have been ringed from 23 nest boxes on the East Yorkshire nature reserve, and early indications are positive, with second broods already being cared for and brood sizes averaging four chicks per pair.
Dave added: "It looks like it's shaping up to be a good breeding season. A monitoring team will continue to check up on the birds at regular intervals, and keep track of their progress."
Ringing is a delicate operation and is only carried out by licensed ringers who take extreme pains to carefully ring and handle the birds. Each ring carries a unique number which allows the bird to be monitored over time. The bird must be recaptured in order to record the data.
For more information on RSPB Bempton Cliffs, visit www.rspb.org.uk/bemptoncliffs.