Avast! There be BTO buried treasure

From Viking hoards to Roman coins, metal detecting can be a very rewarding hobby. Many hours can be spent on the beach or in a field trying to uncover a hidden link to the past or some real life treasure. Why is the BTO interested in this, I hear you ask. Well we are increasingly getting reports of BTO treasure... bird rings!

Metal detector and spade. Taken by Martyn Franklin

The majority of these rings usually belong to birds that have been dead for 10 or 20 years, but our most recent metal detector report from Martyn Franklin was a touch older than that. He was searching near Shipton-on-Cherwell, Oxfordshire when he came across 323412 in nearby farmland.

The mis-shapen ring of Martyn Franklin's find, that has been under the plough quite a few times.

After some searching, the ringing details of an adult Stock Dove were found in the deepest, darkest areas of our archive. Many thousands of ringing records are stored here, covering hundreds of species. This Stock Dove had been ringed 13 km away on 12 March 1943 and is the first Stock Dove to be reported by 'metal detector'. This joined other single reports of 14 species including Brent Goose, Bullfinch, Sandwich Tern, Goldeneye, Wren and Tree Sparrow.

The archive of many thousands of ringing details for birds that are long gone.

The BTO database shows that rings from 67 different species, ranging from Yellow Wagtail to Osprey, have been found over the years by metal detectors. The majority of reports cover urban and farmland birds, but coastal species like Shags and gulls also feature.

One very interesting use of metal detectors has been to find rings in the nests of birds of prey (licences may be needed). Lots of these have been in Peregrine nests or below roost sites and mainly cover thrush sized birds like Starling, Redwing, Dipper and even a Jay. Interesting nest studies in Norway have revealed rings in Eagle Owl nests and to date have found 19 BTO rings including from Oystercatcher, Teal, Common Gull, Tufted Duck, Blackbird and Guillemot.

If you have a metal detector why not get out there and find some bird rings. You never know, you might find one of the first rings ever used, from 1909! Don't forget to report it at www.ring.ac.

A Western Palearctic first highlights another special bird

Expert gull watcher Killian Mullarney came up trumps on Sunday at one of his gull hot-spots at Duncannon, Wexford by managing to identify a Western Palearctic's first Vega Gull on 10th January. This is currently considered a subspecies of American Herring Gull by the BOURC and this mega-rarity is more at home breeding in northeast Asia or wintering in the Pacific.
 

Vega Gull is not the only interest in this photo. Photo by Irish Birding and the finder / photographer Killian Mullarney

The photos published on Irish Birding showed the Vega Gull (centre), but even more importantly to the BTO Ringing Scheme it shows that it is stood next to a colour-ringed Herring Gull: White 8CP6.

Since being ringed on Lihou Island, Guernsey in June 2011, 8CP6 has been seen a few times in Guernsey in the autumn and winter of 2011/12, then after 'going missing' it was seen on Hayle Estuary, Cornwall in January 2015. This is the first bird from the Guernsey project to be found in Ireland. In fact, there are only three reports of foreign-ringed Herring Gulls in Ireland, from Iceland, Netherlands and France.

With more and more birders and ringers enjoying the delights of gulls at rubbish dumps and roost sites, the movements of gulls between countries and local sites can be studied in more detail. One particular Mediterranean Gull for example has been reported in Ireland 80 times since being ringed in Poland in 2011.

"My Precious" Cormorant

BirdTrack's own Nick Moran writes:

The BTO Nunnery Lakes reserve boasts an imaginatively nicknamed ‘Cormorant Tree’, a favoured perching site of…you guessed it…Cormorants. On 23 October 2015, I pointed my new-to-me bridge camera at a metal-ringed Cormorant I’d noticed in said tree. Reviewing the images, I was pleased to see that the first two digits were clearly visible as ‘25’ and the third looked likely to be ‘2’. Not having much experience of L rings, I showed the photos to Lee Barber. The shape and size of the ring and proportionally very large numbering meant he instantly recognised it as not being a BTO ring. Game on!

Numbers 252 confirmed. Taken 23/10/2015

I became Gollum for a week, consumed with an unrelenting obsession to ‘possess’ the One Ring.  And what more appropriate beast to be bearing it than a real life Nazgûl-bird?! Fortunately for me, the wearer of my preciousss was considerably tamer than the other Cormorants, allowing relatively close approach. However, the Cormorant Tree stands right on the bank of the Little Ouse, making it impossible to walk round and unlike the real Gollum, dark, cold and dirty water is not my thing. The only option was to approach from opposite sides of the river on successive visits, striving to see and photograph the ring from all angles.


Through the tree hole. Taken 26/10/2015

Looking fine for (252)39. Taken 27/10/2015





Final digit falls (25239)4. Taken 27/10/2015

By 27 October, after an awful lot of ‘here we go round the Cormorant Tree’, I’d managed to piece together 252394 and the address: Helgoland, Germany. After submitting the sighting to the BTO, the ringing details have just arrived. The bird was ringed as a chick in Wasservogelreservat Wallnau, Fehmarn, Germany on 11 June 2009. Surprisingly, it is only the eighth German-ringed Cormorant to be controlled in Britain & Ireland at the time of writing!


Confirmation of the Ringing Scheme. Taken 27/10/2015

Like all good stories, there was an unexpected twist: whilst clearing some photos from my old smartphone, I came across a ‘phonescoped’ shot I’d taken of a metal-ringed Cormorant on the same branch of the same tree…on 31 October 2014! The digits ‘25’ were once again clear to see, and close comparison of the bill and facial skin confirm it to be the same individual.