Showing posts with label Shetland. Show all posts
Showing posts with label Shetland. Show all posts

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

19 March 2014

Fabulous phalaropes

With so few birds breeding in the UK and even fewer ringed, it's not surprising that we have only had a handful of Red-necked Phalarope recoveries and none of these have been abroad. Very little is known about the life of these tiny birds when they are away from their breeding grounds on Shetland and the Western Isles, but thanks to cutting-edge technology we are getting some extremely interesting insights.

Red-necked Phalarope - Edmund Fellowes

Tiny geolocators, which record the bird's position by a combination of light levels and time, were placed on 10 Red-necked Phalaropes as part of a collaboration between the Swiss Ornithological Institute, Shetland Ringing Group and the RSPB.

Red-necked Phalarope and its geolocator - Adam Rowlands

After successfully recapturing one of the tagged birds a year after ringing, its geolocator was removed and the information downloaded. This revealed an amazing 16,000 mile migration across the Atlantic into the Labrador Sea, then down the east coast of North America to Florida. This bird then crossed Mexico and remained east of the Galapagos Islands in the Pacific Ocean for the winter. On its return in April it followed a similar but more southerly route back. This is the first time a European bird has been recorded taking this migration route.

Migration route of the tagged Red-necked Phalarope
The data gained from this one bird has revealed a wealth of information, not only of the migration route it took but also the timing of its migration and how long it remained at stop-overs. The project will continue to answer other questions including whether all of our breeding Red-necked Phalaropes take this migration route or do some birds join the Scandanavian population, and whether this route changes depending on the weather and local storms. This technology is improving very quickly so it won't be long before we know a lot more.

Thanks to David Okill for letting us know.

26 October 2012

Norwegian Blue Tit update!

We have just heard from our colleagues of the Norwegian Ringing Scheme with an update of the Blue Tit wearing a Norwegian ring that was previously posted.

The first-year Blue Tit was ringed at Lista Bird Observatory, Farsund, Vest-Agder (58'06N, 06'34E) on October 5th. This bird was then caught 9 days later in Lerwick fit and well.


View NOS Blue Tit in a larger map

Alf Tore Mjös writes:
2012 has been another “big year” for Blue Tits in Scandinavia. Many have left the coastline and turned up on the remote island of Utsira 20 km off the west coast, including quite a few ringed at Lista Bird Observatory and Revtangen Bird Observatory. The usual movement of Blue Tits in southern Norway is along the coast from east towards west and then northwest to north.

Fair Isle Bird Observatory has also reported a Blue Tit in a garden while hoping for a Rubythroat. The warden writes on their blog "The last Fair Isle record of a Blue Tit was back on 1st January 1989, there have actually been 3 Rubythroats (including this years) on the island since this commonplace UK garden resident."

Thanks again for David Okill for letting us know and our colleagues in Norway.

22 October 2012

Norwegian ringed Blue Tit in Shetland

Dave Okill writes:

Autumn in Shetland brings falls of continental migrants on south-easterly winds and the end of the second week in October 2012 brought large numbers of Redwings with smaller numbers of Goldcrests, Blackbirds and Bramblings into the Isles. Reports of more uncommon birds were scattered over the next few days and included Olive-backed Pipits into double figures, a Treecreeper and unbelievably a Lesser Spotted Woodpecker, Scotland's first authenticated record.

On the 14th October, an Olive-backed Pipit and a Great Tit were found in a mature wooded garden on the edge of Lerwick. These were joined on the 16th by a Blue Tit which was seen to be ringed with a 'chunky' silver ring. Permission was obtained by members of the Shetland Ringing Group and on the next day the Great Tit and Blue Tit were caught. The ring on the Blue Tit proved to be from the Norwegian ringing scheme.


Blue Tits are very scarce late autumn migrants in the Northern Isles and they do occasionally over winter; in the exceptional year of 1988 at least 40 were recorded but in many years there are no reports, so a ringed bird in the Northern Isles is very unusual.

There have been a number of previous ringing recoveries of Blue Tits to and from the continent but
these have nearly all been from south-east England especially along the channel coast. There have
been 9 foreign birds recovered in England and 10 British ringed birds recovered abroad. The single
Blue Tit recovered from Norway was at Felixstowe, Suffolk. It is possible that some of these birds
moving across the channel could have been ship assisted, but difficult to prove.

We await the ringing details from Norway with interest.

Thanks to Ray Johnston for the photo

22 March 2012

Petrel in Peril

Storm Petrels are amazing little birds. Rarely seen on land during the day and spending the night in their burrows. For a bird which is similar in size to a Greenfinch this bird can make some impressive movements. One such Storm Petrel was ringed in Ona, Norway and controlled by another ringer three days later on the Isle of May (902km)! (Blue pins on map).


Little is known about the winter movements out at sea but they usually leave UK waters in September or October and by November they are around the West African coast. They then head further south to moult near South Africa before making the reverse journey, to get to their breeding grounds in April. We have relatively few recoveries showing this movement as if they die this is likely to be out at sea but 28 have been reported in South Africa so far.


View Storm petrel in a larger map

Finding a Storm Petrel inland is not very likely but one was found on 17 Jan at Shimuwini Bush Camp, Kruger National Park, South Africa! The reason for this was probably a tropical cyclone blowing this bird off course. Luckily this bird was ringed and from the ring number we were able to tell them that this bird had been ringed 172 days earlier on Mousa, Shetland (9,776km, although it was probably more like 13,000km considering it had to fly round West Africa). (Red pins).

Thanks to Mike Pennington for letting us know and Stuart Newson for the photo.

15 September 2010

New Whimbrel longevity record

Allan Perkins writes:
This summer I spent 3 months on Fetlar, Shetland, studying the breeding success of Whimbrel to help investigate their 'recent' declines. Previous studies by Murray Grant on Fetlar and Unst in the 1980s had involved catching and colour-ringing adult Whimbrel, to monitor brood survival and returning rates of adults from their tropical wintering grounds in subsequent breeding seasons. During 1986-88, 97 Whimbrel were colour-ringed and of those the returning rates were high - c. 89% seen the year after ringing - and most birds returned to breed at the same site used in the previous year. Sightings of some of these birds on Fetlar continued up until the mid-1990s, but none had been recorded since then.


It was on 9 May, this year when I first saw one of these colour ringed birds feeding on the short cliff-top turf of Strandburgh Ness, at the extreme northeast tip of Fetlar. Frustratingly it wasn't until 31 May that I managed to get good views of the colour ring combination and amazingly it was a bird ringed in the 1980s.


The bird was identified as EK92102, ringed as an adult breeding on Fetlar on 1 June 1986, and sexed as a male from subsequent observations. Given that Whimbrels do not normally start to breed until they are two or three years old, this bird must be at least 26 years old, making it the oldest known Whimbrel in the world! This surpasses the previous longevity record of 16 years, held by a Whimbrel ringed as a chick on Mainland Shetland in June 1979 and shot in northern France in August 1995.

EK92102 was last recorded in 1995, but it seems likely that it had been returning, undetected, to Fetlar each year since then. Maybe it will return again next year for potentially its 26th breeding season.

Thanks to Allan for letting us know about this bird and also to Murray Grant for the lower photo.