Ringing the entire population output of England in a day!

There can't be that many species where you can say that! On Wednesday night I drove down to Cornwall for my annual Cornish Chough ringing trip. Every year for the past 13 years (since Choughs recolonised England naturally from Ireland) the RSPB have monitored the population and mounted nest-watches using an army of dedicated volunteers. Even though most of the nests cannot be viewed directly the observations of adult behaviour the volunteers make give an accurate assessment of how old the chicks are at each nest and allow me to time my ringing visit to best effect. This year there were five nests still going and luckily there was only about a fortnight between the earliest and latest which meant we could ring them all on one day.

Three Chough chicks safely returned to their nest on a ledge 30ft down a Cornish Tin Mine. Great care is needed taking the chicks out of the nest and returning them as there is still a long way to go to the bottom!! See below

The nests are in a variety of sites comprising three sea caves and two mineshafts. Access is not easy and involves using ropes or ladders so by the time we finished the last nest at 8 pm I was pretty shattered and faced a six-hour drive home!

Seventeen chicks were ringed in all - one brood of two, two broods of three, one brood of four and one of five. By chance there was a serious sex imbalance in the early years of recolonisation, with far more males produced and surviving than females. Happily the estimates of the sex on the 17 chicks ringed yesterday was 9 males and 8 females.

The original Lizard nest is still active and contained three chicks but this year two new adults have replaced the original pioneering pair that has nested there for the past 12 years.

Many thanks to Claire Mucklow of RSPB South West for arranging everything including access permissions and to Nicola, Cat and Keith for their invaluable assistance. Many thanks too to the National Trust on whose land most of the nests are located. More info on the Cornish Chough Project can be seen on their website at http://www.cornishchoughs.org

Virtually all of the Choughs present in Cornwall are colour-ringed which has allowed valuable and detailed records to be gathered on the growth and spread of a natural recolonisation.