Wednesday, 15 October 2014
State of the choughs 2014
It’s 10 years ago since the last UK census of choughs and they’ve just been counted again. Are things getting better or worse? Reg from the RSPB presented some of the survey findings at the Heathlands for the Future seminar on 8th October.
Two thirds of the UK population are in Wales and Llŷn is a very important component, home to 14% of UK choughs. Numbers in Scotland and Northern Ireland have declined and Wales is showing signs of decline with a 48% reduction in Snowdonia and disappearing in Montgomeryshire. In Llanberis there used to be over 65 birds but now they number just a few. On Llŷn there are between 53 to 60 pairs and numbers here are starting to reduce. The only habitat where there are signs of increase is in the sand dunes.
We are fortunate to have the passion and dedication of Adrienne Stratford and Tony Cross who have been ringing and recording choughs in mid to north Wales for the past 23 years. In that time they have ringed 5,000 nestlings, 150 adults and recorded 130,000 sightings. Within Llŷn 1,280 nestlings and 38 adults have been ringed.
Adrienne and Tony have written a report which hopefully will be published soon. One part of the analysis records the first year movements from Llŷn showing long distances of up to 60km – the adults take their youngsters back to the flock or roost from which they themselves originated.
On average males travel 10km from their place of birth to where they breed and the females travel 23km. By spreading themselves out they reduce the risk of in-breeding.
Another analysis looks into their feeding habits with soil and dung invertebrates a key component. After breeding and around July the birds head up into the mountains to feast on bilberries coming back down from August to October to feed on leatherjackets, the larvae of crane-flies. It’s the cow-pats (and pony-pats) that provide the best larder during the winter months.
In late spring I had the privilege of meeting Adrienne in a disused quarry building on the north Wales coast where last year she’d installed a nesting platform from bits of old planks.
A pair of choughs had taken up residence, added heather, lined it with sheeps’ wool and produced two beautiful chicks. They were plucked from their nest into a pillow case, brought down a ladder, ringed, sexed and weighed before being returned to the nest. A couple of times the adults came and shouted insults at us but it was as if they knew the score; it’s that time of year again. As for the chicks, they were quite chilled out and happy to beg food with their plaintive cries and open beaks.
I was surprised to see the tangerine orange colour of their legs. Eventually these and the beak will turn to red.
To Adrienne the choughs are a long running soap opera. She knows their relationships and family histories and 2 of them are now 19 years old.