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. 

Eat like a Gannet

Along with all of the useful data coming into the Demography Team from the Nest Record and Ringing schemes, we also get some interesting or unusual reports. Our latest recovery from Dr Kees Camphuysen, Senior Scientist and Marine Ornithologist at the Nederlands Instituut voor Zeeonderzoek, is one of these:

"I was demonstrating a post mortem for Ecomare animal care staff tonight on an unringed juvenile female Gannet. It was originally found fresh dead on a beach on Texel, The Netherlands, in 2013 but was frozen to keep it in a fresh state until the post mortem."

Juvenile Gannet during post mortem - Dr Kees Camphuysen

"It was severely emaciated but this was not unusual of young Gannets at this time of year but I could feel a very lean and stiff "fish" in the stomach. It was not a fish however. It was a wing...a bird wing, heavily digested and the primary shafts suggested the bird was reasonably large. To my utter surprise, in the muddy blackish, digested remains was....a ring!!!"

The ring was put on a Fulmar chick on 4 August 2013 on Swona, Orkney by the Orkney Ringing Group. Considering this bird was found on 18 October 2013, this chick didn't survive very long. Kees and his colleagues believe the chick may have been eaten by a large fish, possibly a Cod, which was then caught by fishermen, gutted and the offal (including the remains of the Fulmar!) eaten by the Gannet. We will never know for sure what happened but it is very interesting nevertheless.

The contents of the Gannet including blackened feathers and ring - Dr Kees Camphuysen

Orkney Greylags in Norfolk

We have just got details through of some very bizarre movements of Orkney-bred Greylag Geese, which have now found Norfolk to their liking (but who wouldn't?!).

Both DIS and DIU were ringed (and given their orange neck collars) as goslings on 13 July 2008 on Birsay, Orkney. Both were then seen together in Suffolk (Lound Waterworks) on 21-23 December 2008 before moving to Norfolk (Strumpshaw Fen and Buckenham Marshes) on 24 December. They stayed right through to the end of January before being seen back, still together, on Orkney on 6 April 2009. This winter they are now both back at Buckenham, but this time joined by HAJ and HAK, ringed as goslings on Birsay on 9 July 2009! Quite a pattern developing!


These movements seem quite exceptional, but then the Orkney Greylag project only started in summer 2008, so maybe this isn't so new... The project now has funding for another four years so it'll be fascinating to see if more Orkney birds make it to our part of the world.

Interestingly, a lot of the Icelandic-ringed birds now spend their winters in Orkney instead of heading further south to places like Aberdeenshire, Tayside and even Highland. So what are these birds doing??? So all we need are more sightings of neck-collared birds, so keep your eyes out over the winter! Any records can be submitted via www.ring.ac

Interestingly Norfolk has also hosted Greylags from other strange places, with a Spanish-ringed bird (of the Scandinavian population) spending some time in the county (June-August 2004 and February 2005) and also recoveries from as far afield Poland and Germany!

Thanks to Alan Leitch for the info on these birds Alan and Andrew Easton for the photos of the birds in Orkney and Norfolk.