Saturday, 31 December 2011

Young Peregrine travels from Avon Gorge to the West Midlands

I've been colour-ringing peregrine chicks since 2007 with the help of fellow BTO ringer Ade George, and volunteer climbers from the British Mountaineering Council. In each year I have been building up the number of nest sites we visit to maximise how many chicks we ring. With bird ringing (or banding) it is a numbers game - the more birds you ring, the more likely someone will spot one of 'your' birds and report it. With colour-ringed birds this likelihood increases hugely - while only perhaps 2% of birds with just metal ID rings may be resighted, up to 98% of birds colour-ringed may be recovered.

BX - one of five chicks ringed in the Avon Gorge in 2010. Photo by Ed Drewitt.
With my peregrine work the results can be a little delayed. In the first first few years a peregrine's life is very nomadic as it travels around getting to know the region and no doubt look for a mate. So it's not until a peregrine begins to settle at a nest site at two or three years old that it may be seen and identified by birders.

Of my peregrines that have been re-sighted so far, most have been quite close to Bath and Bristol, near where we ringed them. For example, one was seen with a female partner 15km south of Bristol from where it was ringed two years later; another is now the breeding male at a nest in Bath where it hatched; and a third individual was re-seen later in the autumn at the site where it was ringed and had fledged earlier that year.

Our furthest travelled bird however goes to the following individual. One of the young peregrines we ringed in the Avon Gorge in 2010 was also filmed for the BBC's Springwatch.
He was given a blue colour-ring with black letters, BT (his sibling BX is in the photo above)

He was spotted and photographed by Michael Colquhoun in the Malvern Hills, Worcestershire back in April 2011. This was exciting news and it was great to know one of the chicks had ventured so far. 

BT in April, 2011 - now is partial adult plumage in the Malvern Hills. Photo by Michael Colquhoun
BT's colour ring clearly visible. Photo by Michael Colquhoun.
However, I then had sad news in October 2011 that a peregrine with one of my colour-rings had been found dead by a dog walker not far from KIdderminster in the West Midlands. After exchanging e-mails with local birder Jason Kernohan who met the dog walker and recovered the dead bird, I discovered it was the same colour-ringed individual, BT. 

He had been dead for four days before being found (as indicated by the development of moaggots). He was taken to a vet by the police for an x-ray to confirm he hadn't been shot. He had been found below power lines and seems likely he had died from some interaction with these. 

BT's colour ring. Photo by Jason Kernohan
BT's metal BTO ring. Photo by Jason Kernohan.

Despite this young bird's death I'm pleased we know his final outcome and where he travelled. It helps build up a bigger picture of what peregrines do when they fledge. It's interesting that we've not heard from the other four chicks that were in that same family. Yet we have heard from this individual twice! Hopefully as the other four (assuming they are all alive) begin breeding they will be spotted and identified by myself or someone else watching them.

Tuesday, 6 December 2011

A murmuration of Starlings close to home

Here's the sounds of thousands of starlings at roost!

And here's my own running commentary of the same experience close to my home:

There's been a lot of publicity recently on the incredible starling experiences across the UK where millions of these gregarious birds form swirling shapes movements, moving through the sky as a single entity like a squidgy, amoeba changing form and size every second! It leaves those watching it for real or viewers online or watching tv with mouths wide-open, in awe at the sheer complexity, beauty and form. 

Here in Bristol, one of the most well known starling experiences is about an hour away down on the Somerset Levels. Millions on starlings roost in the reedbeds, feeding by day on the farmland across Somerset. Even more mind-boggling is that huge numbers of these birds originate from Russia and eastern Europe which is currently very much colder and frozen compared to the west of England (where it's just wet and mild!).

In the past few weeks thousands of starlings have been performing this incredible display close the second Severn Crossing on the Severn Estuary near Bristol. It's only ten minutes drive from my home and an awesome opportunity to watch such a spectacle so close by. They were swirling round above my head and so close I could even smell their compost-like scent! And once the mass drop down in the bushes, they break their silence and burst out into a cacophony of squeals, whistles and gurgles as they squabble over their roosting space!at

I captured (above) this murmuration of starlings on the Somerset Levels in February 2010.

Colour-ringingd Robins - alas, halted by the British weather again!

The British weather - a phenomenon we always seem to be talking about and something where there is genuinely (arguably!) always something to be chatting about! And this morning is of no exception. Helping a Masters student at the University of Bristol with a project on robins we were all set for catching and ringing a few more this morning - but then at 4.30 this morning the rain was beating against my bedroom window and the wind speed had turned from calm (and clear starry skies) to gale force! Time to cancel and re-arrange - again!

The project itself involves carefully catching the robins in  a mist net, putting special colour rings that denote each individual on their legs plus a metal ring issued by the British Trust for Ornithology. Our red-breasted friends are then measured, aged and weighed before being released.

Dan, whose Masters project this is, is looking at the alarm calls of the robins and how the individuals
interact with each other - hopefully over the next few weeks before Christmas we'll be able to ring a few more to help Dan know who is who.

Below is a photo of one of the colour-ringed robins - I'm especially interested to see whether any of the robins disappear (perhaps as migrants) and who stays around or the spring to breed.