Thriving Stonechats at Dersingham Bog

Published on 15 March 2017 in News and comment

A collaborative project to find out more about the Stonechats at Dersingham Bog NNR, in Norfolk, has been running since 2012. Natural England has teamed up with the North Norfolk Ringing Group, the BTO and site volunteers to begin ongoing nest monitoring work for Stonechats, among other key heathland breeding species.

The project aims to survey and colour ring breeding Stonechats on Dersingham Bog and record adults and juveniles seen outside the breeding season, both on the reserve and elsewhere in Norfolk, inland and along the coast. This will help to build a clearer picture of where this locally scarce species breeds as it spreads further around the county. The project will also provide information on the site fidelity of individual birds, as well as generating data on productivity and fledgling survival.

The number of breeding pairs of Stonechats on the reserve has risen dramatically in recent years, resulting in high numbers of ringed birds dispersing from the site.

The first few years of the project saw relatively low numbers, with 5 pairs and 10 juveniles as a maximum. However, 2015 saw a big increase when 10 pairs produced 51 ringed juveniles from 18 nests. It was more than the combined total of the previous three years. But then the 2016 breeding season surpassed all expectations as the number of pairs rose to 13 and the total number of juveniles ringed climbed to an amazing 95.

Some pairs made three nesting attempts, although only one pair managed to fledge all three broods this year. That female is one of then site’s most prolific breeders; 2016 was her third year of nesting on the reserve and her progeny are already establishing new pairs on the reserve.

The project aims to gather information on the number of eggs laid, how many eggs hatch, how many young survive to be ringed and the eventual fledging success. Under licence, all Stonechat nestlings at Dersingham Bog are ringed with a combination of a grey plastic ring over a metal ring on the right leg, with two colour rings on the left leg to allow them to be identified individually.

Since breeding numbers have increased on the reserve, there have been so many young Stonechats ringed that the order of the rings on the right leg had to be changed in order to give more options.

So some Stonechats from the 2016 broods onwards will now sport a metal ring over a grey plastic ring on the right leg, a reverse of the original order, as well as a two colour combination on the left leg.

The project workers are keen to receive sightings of our colour-ringed birds, both on Dersingham Bog and elsewhere in Norfolk and along the Wash coasts to see where the young disperse to over the winter and whether they return to the Bog to breed or set up territories elsewhere.

Further details of the project and an easy way to report sightings of colour-ringed birds are at https://northwestnorfolkstonechats.wordpress.com You can also reporting sightings via Twitter https://twitter.com/NWNfkStonechats or via email to Tom Bolderstone northwestnorfolkstonechats@gmail.com