An update from Tegan Newman, a member of our Orkney seabird tracking team.
Having a whale of a time on Muckle Skerry
Somehow, over a month has disappeared since Derren’s last blog so here is a summary of what has been keeping us busy in Orkney….
Having arrived on Orkney in April after witnessing a shocking year for seabird productivity on Fair Isle last year, I was really hoping to see a positive change in the state of the seabird cliffs this year and get a small taste of what the once-thriving colonies may have looked like (Kittiwakes alone have declined 87% in Orkney from 24,000 to 3,000 since the year 2000).
In late June, Derren Fox and I camped out on the stunning uninhabited island of Muckle Skerry to try our luck at deploying GPS tags on nesting kittiwakes – something I had not done before as the kittiwakes had all failed on Fair Isle the previous year (in fact, no chicks have successfully fledged there since 2010)! The colony on Muckle Skerry is special because it’s in a long gully that you can hear (and smell) long before you actually see it. Approaching on foot, we could already hear the distinct cacophony of a bustling kittiwake colony, with the very recognisable “KITT-I-WAKE” calls resonating around the cliffs as noisy neighbours grew impatient with each other, or pairs of birds converged together again after a brief separation at sea. As we rounded a corner and saw it for the first time, it was brilliant to see the ledges alive with a frenzy of active birds; nests inches apart from each other, all occupied by protective parents guarding eggs or chicks, which seemed to be spilling out from the cliffs. It was a very special sight to behold after the plight of previous years.
Part of the Kittiwake colony on Muckle Skerry (photo by Derren Fox).
Kittwake with chick (photo by Derren Fox).
We managed to deploy 16 GPS tags on adult kittiwakes to assess where they were foraging for food and the results are encouraging. All of the birds on Muckle Skerry appear to be feeding locally – with the fast moving currents of water around the island providing a bountiful supply of fresh fish and meaning that adults are barely having to leave their nests to find enough food to raise their young chicks. One of our birds made a record 20 separate foraging trips within 24 hours!
Kittiwake (Photo by Derren Fox).
From our personal observations, it also seems that predation by gulls and skuas is much lower on Muckle Skerry than we have witnessed elsewhere on Orkney, possibly due to the fact that they are also benefiting from the fertile waters surrounding the island and therefore do not need to resort to hunting small chicks or eggs. However, whilst our results are tentatively more promising this year, there is still a very long way to go before numbers are anywhere near being back to what they have been in the past and it is only with continued monitoring that we can try to understand the patterns in population changes.
A gull feeding frenzy in the fast flowing waters surrounding Muckle Skerry (Photo by Derren Fox).
It’s not all birds that appear to be benefiting from the fertile waters of the Firth this year . The undoubted highlight of the camping trip was the sight of four killer whales circumnavigating Muckle Skerry for over an hour one evening. At one point they were tail-slapping and loitering off an apparent ‘hotspot’ amongst the up-welling water at a very close distance to us. Credit definitely needs to be given to Derren at this point who successfully recorded the event with some stunning photography – I on the other hand was completely useless as I was so excited.
A killer whale, disgustingly close (Photo by Derren Fox).
Another perspective of the killer whale spectacle (Photo by Derren Fox).
We have also had the privilege of working in collaboration with the Orkney Ringing Group up here on Muckle Skerry and Swona to try and investigate the over-wintering destinations of some of Orkney’s puffins and razorbills. We've been using miniature light-logging geolocators, weighing in at 2 grams, which record sunrise and sunset and longitude and latitude, which tells us the location of the bird in the world! Due to their small size and weight, these geolocators can be fitted to the bird’s leg and left for a whole year without causing any irritation or disturbance to their usual behaviour.
Razorbill with geolocator (Photo by Derren Fox).
This kind of research is incredibly exciting because although we know that the birds faithfully return each year to breed on these islands, there is still a relative black hole in the knowledge of where they disperse to over the winter – something that is important to find out from these colonies in Orkney where numbers of auks have declined in recent years, possibly as a result of increased over-winter mortality. On the successful retrieval of the geolocators this time next year, it will not only be possible to observe where the birds have been during the non-breeding season, but also whether they’ve been resting on land or at sea (the devices can detect whether or not they’re in salt water). We’ve also managed to deploy the geolocators on both parents in some nests, so it will be possible to see the differences in couples over-wintering behaviour and their subsequent arrival back at their nesting sites next year.
Razorbill (Photo by Derren Fox).
Puffin (Photo by Derren Fox).
Seabird monitoring isn’t all about the latest technology though. This season’s tagging work is drawing to an end now that most chicks have fledged, or are impatiently shuffling on their ledges in preparation to leave. But there is still time to head back to Swona with the Orkney Ringing Group for some reliable, old-fashioned ringing of the fulmar chicks before they fledge in late-August/September. Ringing recoveries are still invaluable in terms of long-term monitoring and can provide vital information about dispersal and feeding behaviour, site fidelity, mortality and longevity. The oldest known fulmar in Britain was from Eynhallow in Orkney and it’s thanks to ringing that we know that ‘Flora’ was ringed as an adult in 1951 and was last seen in 1992 back on Eynhallow, an impressive 40 years and 10 months later!
Fulmar (Photo by Derren Fox).
That’s about all for now, other than to say a big thank you to Derren Fox for his advice, patience and general good company this summer. Also, for the use of his photos! Here’s a final one of a European Shag that doesn’t really fit in with anything I’ve written about but it’s too good not to include!
European Shag (Photo by Derren Fox).
Finally, just time to say a big hello to the other STaR teams – I’m looking forward to a post-season catch up very soon! Check out the other blogs from Fair Isle, Colonsay and the west coast to find out how they’ve fared this summer.
Thanks a lot for reading,
Tegan
Read more about STaR team research by following the links below.
http://www.rspb.org.uk/community/ourwork/b/scotland/archive/2014/07/28/what-a-brilliant-breeding-season.aspx
http://www.rspb.org.uk/community/ourwork/b/scotland/archive/2014/07/07/chicks-galore.aspx
http://www.rspb.org.uk/community/ourwork/b/scotland/archive/2014/06/24/tracking-seabirds-and-tackling-the-stenness-monster.aspx
http://www.rspb.org.uk/community/ourwork/b/scotland/archive/2014/06/02/tracking-seabirds-on-fair-isle.aspx
http://www.rspb.org.uk/community/ourwork/b/scotland/archive/2014/05/15/seabird-tracking-takes-off.aspx
http://www.rspb.org.uk/community/ourwork/b/scotland/archive/2014/08/04/seabird-tracking-from-the-shiants-to-orkney.aspx