Thursday 4 August 2022

Tagged Shearwaters

 Tagged Shearwaters in Cardigan Bay.

Researchers from Ox Nav (Oxford University Navigation Project), have been tagging Manx Shearwaters on Skokholm and Skomer Islands to study their movement and behaviour. Results are showing that many of these birds have been spending time in Cardigan Bay, some of them certainly among the huge numbers seen regularly off Aberystwyth and Borth.

The number of tagged birds is small, 200 or so over the course of the season, and only a few, maybe up to 20, at a time, and very few at the moment.

The researchers catch the birds as they come to their burrow, and attach the tag, which has a battery life of up to two weeks, and then re-catch the bird when it returns to its burrow a few days later, and the data can be retrieved.

The tags record a GPS reading, once per minute, and have accelerometers which record the birds movement, many times per second. This records every wingbeat !

The tags are small, and not conspicuous when on the bird, but they can (with luck) be seen on a good quality photogr  No photographs of tagged birds in Cardigan Bay have ever been returned to the the project !!

By comparison, Balearic Shearwaters tagged in Majorca, are regularly photographed, particularly in the vicinity of the Scilly Isles. The density of birders with long lenses is higher in the Scillies !

So if any Ceredigion birder, has shots of the manxies, and a few idle moments, it could be worth a scan to see if you can be the first to spot a tag !

Dr Ollie Padget would be happy to see any pictures,

https://oxnav.web.ox.ac.uk/people/ollie-padget

More details of the project here,

https://www.oxnav.org/save-our-shearwaters

It’s a hot topic, as you may know, there are plans afoot for floating wind turbine arrays in the Celtic Sea. Here are some details of Project Erebus, https://www.bluegemwind.com/our-projects/erebus/

How vulnerable will our seabirds be to offshore turbines ? No one really knows yet.

We normally see shearwaters flying at low level, below turbine blade height, but in high winds or stormy conditions they fly higher, but not much is known about how high. More research needed !




Dave Purdon.