18 September 2018

Very special Nightingale at Leybourne Country Park

Alan Woodcock writes:

Leybourne Country Park was opened in 2004 and is part of an extensive area of former sand and gravel workings, which was excavated between 1946 and 1977. Much of the area is therefore 'man made' with landscaping and planting having taken place as part of the restoration during the late 1970s. It comprises 93 hectares, of which 65% is water, 10% marshland and reedbed, 15% grassland, 6% trees and woodland and 4% scrub. The Park is sandwiched between the villages of Snodland and New Hythe in the Medway valley about five miles south of Rochester in Kent.


Nightingale became established in the general area of the park towards the latter end of the 1970's. The main Nightingale habitat is hawthorn / bramble scrub and willow / hawthorn / buddleia scrub with adjoining open areas.


Nightingale scrub habitat - photo by Alan Woodcock
In 1980, I recorded three singing birds around a gravel pit (Abbey Meads), which is separated from the Park by the Snodland to New Hythe railway line, and by 1991, the number had increased to ten pairs (five in the Abbey Meads area and five in the Country Park). The count for 2016 was twenty five singing birds, with five in the Abbey Meads area.

The Park now holds a very important population of Nightingale, with up to thirty singing birds in some years. A dedicated team of rangers and volunteers have helped to create and maintained Nightingale habitat throughout the Park.

Footpath by Nightingale habitat- photo taken by Alan Woodcock
Between 1979 and 1992, an area known as Reeds Island Site, which is just across the Medway from the Park, also held a high population of Nightingale (Kent Bird Report 1991, The Burham, Eccles and New Hythe Nightingale). Although Nightingale still breed in the general area, without habitat maintenance and the recent solar park development, the population is now much depleted, which makes the Leybourne Country Park's population even more important.


Singing Nightingale - photo by Alan Woodcock

Good Nightingale habitat - photo by Alan Woodcock

T677063 was ringed in the Pylon territory on 6 June 2008, as a 5 (hatched the previous calendar year) male. Five years later when I re-trapped him on 17 April 2013, he was holding a territory in an area known as Brook House, which is about 300 metres away. He was subsequently retrapped there in 2014 and 2015.

On the early date of 4 April 2016, I heard a bird singing in the territory he held in 2015; I set up a net the following day and caught the bird, but instead of it being T677063, it was an unringed, age 5 male. Although I was disappointed, with it being so early in the season, I felt he still might return. A while later I was told by a bird-watching friend that he had seen a Nightingale with a ring singing in a different area about 400 metres away. On 4 May, I set up a net and managed to catch the bird and on reading the ring number much to my delight it was indeed T677063. He was then re-trapped there on 20 July and it was this capture that made it to the Online Ringing Report longevity pages, breaking the previous British and Irish longevity record for this species.

Ed - Submission of the recapture data for this bird has been delayed and it broke the longevity record for this species in 2016. It wasn't beaten in 2017 so this bird is the current record holder.

10 August 2018

"Roll up, roll up". Bird ringing at the fair.

All over the country, qualified bird ringers run demonstrations for individuals, groups or anyone coming to a particular site, such as a nature reserve or a farm. These can be fantastic events for engaging non-ringers, highlighting the scientific importance of ringing and explaining what we can learn from monitoring birds.

One of the biggest ringing demonstrations in the country is at Birdfair (17-19 August). Every year, thousands of people stop by to see how ringing works and to view birds close-up, without the need for binoculars.

Guy Anderson showing the crowd

The Birdfair ringing demonstration runs for the duration of the fair (weather permitting) and, if previous years are anything to go by, should provide visitors with views of some great species. Last year, a Sparrowhawk was caught and really drew in the crowds. The more commonly-caught species include Blackcap, Reed and Sedge Warbler and a whole host of tits and finches.

Anyone want to see a Sparrowhawk?

This site, and locations nearby, are usually ringed by the Rutland Water Ringing Group, and this demo helps to increase the effort on the site and adds to the data already collected from their other projects, including their CES.

And if we don't have any birds to ring, we are usually able to 'ring' people with specially-designed rings... If you are going to the fair this year, do come along and find out what it's all about!

08 June 2018

A big jump in Hawfinch Longevity

With the influx of Hawfinch into southern Britain this winter, Jerry Lewis started one of his feeding sites much earlier than usual (in mid January) hoping to try and catch some of the visitors. Despite a decent sized flock of 40+ birds visiting the feeding site, they were mainly coming down to Hornbeam seed, rather than sunflower seeds. After two months, catching had been very slow (just 16 birds caught, at a rate of one every three hours), but after mid March it started to pick up. The largest catches began from mid-April onwards (as happens most years), averaging a 'finger numbing' two birds per hour. 

Despite problems at two of the feeding sites - sunflower seeds being taken by squirrels/wild boar (leaving few for the birds) and a road closure preventing access to a third site, it was Jerry's most successful year to date. By the time his 'catching season' was over he had caught 202 birds, which included 43 that had been ringed in previous years (plus a small number of same-season recaptures). It is unlikely that many (any) would have been continental birds, as migrants had generally left by early April in previous years.

Photo by Vaughan Thomas  Hawfinch NW31779, ringed 1 May 2008 and re-caught 5 May 2018 (10 years, 4 days later)

Five of his recaptures had originally been ringed in 2010, making them comparable with his current British & Irish longevity record of 8 years 1 month 22 days. One female, caught on 5 May 2018, topped these however, having been ringed on 1 May 2008, 10 years and 4 days earlier; a big increase in longevity. This bird was ringed in the northeast of the Forest of Dean - nr Cinderford, was caught twice in April 2010 - near Tintern in the Wye Valley (20 km SSW), before now moving to near Chepstow (7 km further SSW).

What seems to be surprising is how rarely the 2010-ringed birds had been re-caught (three had been caught once since ringing, the other two hadn't been re-caught at all). Jerry's next challenge is to try and understand why these long-lived birds are not re-caught more often.

17 May 2018

How long do Red-throated Divers live for?

Dave Okill of Shetland Ringing Group writes:

On  26 April 2018, Mick Mellor was doing a routine Beached Bird Survey for SOTEAG (Shetland Oil Terminal Environmental Advisory Group), when on Urafith beach, North Mainland, Shetland he found a freshly dead Red-throated Diver (RTD) that had a ring on it. He carefully noted the number and emailed me when he got home. 

Not remembering the number, I started to look back through old, almost fading, files and I found that I had ringed it as a large chick on a small remote lochan not far from Nibon, North Mainland, on 27 July 1985. At well over 32 years old, this individual was an old bird. Looking at the BTO longevity records, the oldest-known RTD was a bird ringed in Hoy, Orkney in July 1986 and last caught at the same location in April 2015, 28 years, 9 months and 7 days later; our bird clearly beats that by some margin! Searching through North American and other longevity lists, it seems that our bird is probably the oldest RTD yet recorded anywhere.

Ringed Dead Red-throated Diver, Urafirth Beach, Shetland. Photo by Mick Mellor.

As well as demonstrating essential information on migrations, movements and dispersal, ringing also gives us the ages of different species; both the average age and the maximum age of the oldest individuals. Longevity records usually creep up slowly, so an increase in the maximum age of RTDs by four years is a notable leap. I suspect that divers are long-lived birds and this record will be well beaten in time.

The ringing site and the finding place are only a few kilometers apart and it is likely that this bird was a male returning in spring to nest in its natal area. Male divers return to breed close to the area where they fledged; females disperse widely before they breed and Mainland-ringed females have been found many kilometers from their fledging loch, up to the North Isles and as far as Orkney. Orkney females have also been found breeding in Shetland.

Red-throated Diver. Photo by Manuel Schultz/BTO.

Over the years our bird will have traveled widely but we only know two points in this bird's life. To help us understand divers better, JNCC are promoting a project to discover what divers are doing, especially on their wintering grounds, now especially important with the proliferation of vast off-shore wind farms which displace wintering and moulting birds from their traditional areas. Birds from Orkney, Shetland, Finland and Iceland will be investigated.  

Editor's note: all recoveries of ringed birds help to further our knowledge, so if you find a bird ring, please report the details at www.ring.ac

12 April 2018

Birds of a feather, fly together

It's pleasing to have a flock of Siskins arrive in your garden, and thanks to ringing, we might know where they come from or go to, but can ringing tell us anything about the link between these individuals in the flock? A note in Bird Study by Juan Senar and Jeff and Allison Kew in 2015 revealed that the individuals in Siskin flocks have stable social bonds and move in stable social units.

Two more recent examples of Siskins apparently travelling together between Britain and both Finland and Sweden provide even more evidence to reinforce the existence of social bonding between migrating Siskins.

Hugh Insley writes:

The moment you take a ringed bird out of a net and realise that the number on the ring is not one of your own, is always pleasing. When the ring has a foreign inscription the pleasure rises to excitement.

Swedish ring being examined. Photo by Sandy Davidson

Following several spells of easterly winds this March, I wasn’t entirely surprised to find that one of the Siskins visiting my garden feeders (green pin on map below) was carrying a Swedish ring and had been ringed as a 5,M (last years fledgling, male) on 25 April 2017 at Overboda, Västerbotten (63 deg 51 min N 19 deg 55 min E) 1,490 km ENE of Inverness (red pin on map below).

Swedish Siskin recoveries are not as frequent as might be expected from such a close neighbour. Up to 2016 there had been 38 Swedish-ringed Siskins reported here, with 110 BTO-ringed individuals recovered there. This compares with 105 from, and 172 to, Norway. So, even though another bout of easterlies had followed, I was quite surprised to catch another Swedish ringed Siskin, on 4 April and even more so to get a third the following day. What was really interesting was that the third bird’s ring, was only seven numbers different from the bird caught the previous day so that it was nearly certain that these two birds had been ringed at the same location and were travelling together. Both birds had been ringed on 23 July 2017 at Handol, Jamtland (63 deg 16 min N 12 deg 26 min E) 1,119 km ENE of Inverness (blue pin on map below).



An email exchange with Malcolm Calvert of the South Manchester Ringing Group, with whom I swap quite a number of Siskins, revealed that he had had a similar experience over the weekend of 22/23 February 2016 when one of six Siskins caught in his North Cheshire garden was an adult and was carrying a Finnish ring; the bird had been ringed at Pori, Satakunta, Turku and Pori (purple pin on map below) on 15 May 2015. The following day Malcolm caught another six, and was delighted to learn that one of these had been recaptured two months later on 29 April 2016 at Niinivisi, Kupio  Finland (yellow pin on map below), albeit some distance from the ringing location of the Finnish ringed bird caught in his garden (brown pin on map below). Finnish recoveries are even scarcer than those from Sweden with only four Finnish-ringed birds reported here and 28 BTO-ringed ones reported in Finland up to 2016.



Two male Siskins squabbling over seed. Photo by Desmond Dugan

Any foreign recovery is interesting, but to find two different examples of pairs and probably groups, of Siskins apparently moving together is remarkable. It seems likely that Malcolm’s two Finnish recoveries involving his Cheshire garden would have involved birds that had been wintering in Britain. The Swedish birds in my Inverness garden could also have been birds that had wintered in Britain, returning north with all the other Siskins which seem to move up into the Highlands in March and April. Many of these travel via the Manchester area, as evidenced by all the exchanges with the South Manchester Ringing Group, or perhaps they might have been the result of drift migration following all those easterly winds?

Siskins at a feeder. Photo by Desmond Dugan

Siskin was the sixth most-ringed bird in 2017 with in excess of 35,000 individuals ringed. Even so, or perhaps because of this effort, every year is bringing new knowledge to our understanding of these charismatic little garden visitors.