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. 

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.

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