17 July 2014

New BTO project initiated - Gull Positioning System (GPS)

This summer, 50 Lesser Black-backed Gulls breeding on Skokholm Island, Pembrokeshire and Walney Island, Cumbria have been kitted out with state-of-the-art GPS tags by scientists from the BTO as part of a project funded by the Department of Energy and Climate Change, studying how these birds might use areas of the marine environment earmarked for the development of offshore wind turbines, as well as areas where wind farms already exist.

The Lesser Black-backed Gull was classed as “Amber” in the most recent Birds of Conservation Concern and is declining at a number of breeding colonies where it is protected, included Skokholm and Walney. These tags gather high quality information that is already providing valuable insights into the habitats these birds use, which could be used to improve their conservation and management.

Lesser Black-backed Gulls breeding on Skokholm Island, photograph by Richard Brown

The birds were tagged in May, at which time they were incubating eggs and we are now receiving regular updates on where they have been, the altitude they are flying at and how long they spend in certain areas. Initially almost all birds from Skokholm went inland every day to feed, visiting reservoirs and agricultural areas throughout Pembrokeshire and Carmarthenshire, as well as towns like Milford Haven and Pembroke. However, once their chicks started hatching towards the end of May, birds began to fly out to sea, suggesting these gulls were seeking high quality fresh fish for their youngsters. Recently, one female travelled as far as the Isles of Scilly before returning to her nest site, while another bird visited Great Saltee Island off the coast of Ireland.

A Lesser Black-backed Gull breeding on Skokholm makes a day trip to Ireland

Lesser Black-backed Gulls tagged on Walney Island have spent time in Barrow and other local urban areas, where gulls are not always popular. However, many birds have flown straight over these locations on their way to parts of the Lake District, while others have journeyed far out into the Irish Sea. Birds that do visit towns have tended to favour destinations like Blackpool, while others have made day trips as far afield as Warrington.

You can see where our birds have been going for yourselves if you keep an eye on these pages hosted by researchers at the University of Amsterdam, who made our gulls’ tags:



This project would not have been possible without the help of Skokholm Wardens Richard Brown and Giselle Eagle, and Matt Lipton, Warden at South Walney.

For more information on this BTO project and to watch our gulls on the BBC One Show click here

16 July 2014

Namibian Common and Spanish Roseate 'tern' up in the UK

We often blog about the photographers capturing images of ringed birds (such as the Spanish Black-necked Grebe, wandering Bearded Tits, Sandwich Tern in the USA, a lost Snow Bunting and a returning Great Grey Shrike), but we do also get plenty of people reading rings with good optics.

We recently received a run of reports of ringed Common Terns read with a 'scope at Preston Dock. Most of these were birds ringed at Shotton Steel Works or Banks Marsh on the Ribble estuary; all relatively local if you're a long-distance migrant. Interestingly, these birds were all at least five years old (and up to 11 years old), but then the recent decline/crash at Shotton means there are fewer birds to resight, so the story is never that simple! It's not all bad news at Shotton though, as the colony has recovered somewhat this year, with over 350 chicks ringed recently.

But two birds also really demonstrate what these birds get up to when not on our shores. 4H58786 was a bird ringed in Namibia in March 2011 and currently paired up with an egg at Preston Docks: there are fewer than 10 records of Namibian-ringed Common Terns in the UK. The other ring was a French ring, M26822, possibly ringed in Senegal in or around 2000, but details aren't clear yet. More details on Common Tern movements can be found in the latest version of the BTO's Online Ringing Report.

4H58786 at Preston Dock (Paul Slade)

This sequence of photos shows the effort needed to read a ring
from photos, but the effort was certainly worth it (Chris Batty)
Interestingly, Preston Dock also produced another fascinating recovery report recently. A ringed Great Skua found there on 15th June proved to be from Norway (ringed on in Herøy in August 2013), but had to be taken into care by RSPCA. Extra details and photos of this bird are on the Bamber Bridge Birder blog.

NOS 3033460 before being taken into care by RSPCA (c) Bamber Bridge Birder
As if the run of records from Preston Dock wasn't enough, the northeast hit back last week with an equally notable ring read. Coquet Island is well known as the largest British (and only English) breeding colony of Roseate Terns and birds from here are regularly ringed by the Northumbria Ringing Group (experience the thrill of a ringing visit to the island on this BBC Radio4 Living World programme). But when the RSPB warden Wez Davies recently read ring 1V015109 it certainly wasn't a BTO ring! This turned out to be a bird ringed at Salinas de la Tapa, Cadiz, Spain in August 2010.

Northumbria Ringing Group hard at work on Coquet Island

What makes this ring read so exceptional is that it's the first EVER recovery of a foreign-ringed Roseate Tern in the UK. Ringing of birds as chicks is commonplace at the few extant colonies, and we have over 500 foreign recoveries of these birds (all detailed in the Online Ringing Report - it really is a great source of information!), including over 260 in Ghana, 32 in Ivory Coast and 18 in Togo.

***STOP PRESS*** We've also just heard from Coquet Island that after reading the Spanish Roseate Tern ring, warden Wez has also found a dead Common Tern with a 'Pretoria' ring on it: 4H51221. This could be a bird ringed in South Africa but, as for the above bird from Preston Dock, could also be from Namibia. Watch this space for further details...

Thanks to Paul Ellis for the reports, from the Fylde Bird Club website, of the Preston Dock birds and to Tom Cadwallender and Chris Redfern for chasing up the Coquet records.

10 July 2014

Hawfinch longevity on the up

The longevity record for a British ringed Hawfinch has stood for many decades at 6 years, 9 months and 4 days: not surprising really as so few had been ringed, and even fewer recaught or found.

BTO ringer Jerry Lewis spends most of April each year catching (and more importantly recatching) and colour-ringing birds at feeding sites in the Forest of Dean. In 2012, he caught three birds that he had previously been ringed six years earlier, and began to think that a new longevity record was perhaps in sight. He didn't have to wait long, as soon after this he caught another two birds that had been ringed in 2005: NW21506 was the older of the two, at 6 years, 11 months and 24 days. Fast forward to 2013 and another two seven-year-olds were recorded, but photographed this time allowing their colour rings to be read. This gave an impressive selection of old birds, and a better indication of the actual age that Hawfinch can regularly reach.

However, in April this year, local birder Phil Mugridge photographed a bird with a red colour ring over a metal right on its left leg, a combination only used on 17 birds ringed in April 2006, so an even older bird at eight years.

LBR,M in April 2014
The next few years are likely to see further captures and sightings of birds originally ringed in 2005, 2006 or 2007, so no doubt the longevity record will continue to be pushed even higher.

Thanks to Jerry for letting us know about this excellent project and to Phill Mugridge for the excellent photo of this old age Hawfinch.

03 July 2014

Half time update for CES

Andrew Harris & Roger Kiddie write:

After a trial year in 2012, we started two dry scrub Constant Effort Sites (CES) last year at the RSPB Northward Hill reserve. In 2012 we did the full 12 visits at one of the sites and seven visits at the other. The results from 2013 showed that adult survival was 37% down, but productivity was 23% up from 2012.

This year we speculated that with the mild winter, adult survival for resident birds would be up but we had no idea what the numbers of returning migrants, mostly Sylvia warblers, would be. We hoped that with a better breeding season than the last two years, productivity would also increase.

We have now completed the first six visits at each site. We have had 244 adults compared with 202 in 2013, showing a 20% increase. Residents have increased from 100 to 112 and migrants from 102 to 132. The species showing the largest increases are Dunnock (20 to 30), Blackcap (26 to 47), Wren (9 to 17), Lesser Whitethroat (10 to 19) and Chiffchaff (15 to 19). Whitethroat are the only species whose numbers have decreased (37 to 34).

Male Blackcap - Adrian Dancy

With the mild spring / early summer, juvenile numbers have been significantly up on last year (115 to 297) showing a near 160% increase. The most obvious increases have been in Blackcap (16 to 87), Wren (1 to 19), Robin (9 to 23), Dunnock (17 to 31), Blackbird (4 to 25), Blue Tit (25 to 48), Great Tit (6 to 19) and Long-tailed Tit (3 to 8). The only species obviously down at this stage of the season is Chiffchaff (19 to 16).

We are aware that our data aren’t representative of all the CES projects nationally, but we are encouraged by what appears to be happening on our site. We have 98 years’ worth of ringing experience between us but until 2012 we had never been involved in CES ringing. We have thoroughly enjoyed the experience and we feel it is good discipline both for us and our trainees and are happy to contribute to one of the BTO’s target ringing projects.

22 June 2014

Spanish Black-necked Grebe breeding in UK

The age of digital photography has seen a rapid rise in the ability of photographers to capture details on metal rings as well as colour rings. In the 'good old days' the occasional Oystercatcher or gull ring would be read, but now it's commonplace for us to receive ring reads of species such as Goldfinch and Lesser Redpoll at bird feeders. But top marks go to Mike McKenzie, who's been putting in a lot of effort recently to photograph breeding Black-necked Grebes at a confidential site in northern England.

Black-necked Grebes breed at fewer than 15 sites in the UK
Much to his (and our!) amazement several of his photos revealed one of the birds was ringed, so he duly got in touch. As unlikely as this might be, we presumed it would be one of the small number of birds ringed in the UK over the last few years, but previewing the first image proved otherwise. The font of the numbers was blatantly not ours, so this must be a foreign bird!

Cropping high-res versions of the images allowed us to just about make out the words AMBIENTE and MADRID on the ring - a Spanish bird! We were then able to piece together the full ring number and thanks to a quick email to the Spanish Scheme, we know that this bird was ringed in October 2012 at Paraje Natural Marismas del Odiel in southwest Spain. This wetland area is second only in size to Parque Nacional de Doñana in the region, with significant breeding populations of many waterbirds. The wetland does support resident Black-necked Grebes, but is obviously also winter home to some of our own breeding birds.

Just one more gratuitous photo of one of the breeding birds!
This is our first foreign recovery of Black-necked Grebe, with the only previous recoveries being local colour-ring sightings, and is a significant one in linking together these two distant populations.

Many thanks to Mike for getting in touch and letting us use his excellent photos on the blog. And if anyone wants to go one better than a first, then get your camera out...