Seabird tracking from the Shiants to Orkney

4 Aug 2014

Emily Scragg, Senior Research Assistant, gives us an update from the STAR west coast roving team.

Seabird tracking from the Shiants to Orkney

It is coming towards the end of our field season and we have settled down in our last location for this year – on Orkney! Which is an unusual place for a ‘West Coast’ team to end up: here’s how we did it:

We started off the main part of the season working on the Shiants, a group of islands in the Minch between Skye and the Outer Hebrides. The main razorbill and guillemot colony here is in a large boulder slope which you can only access from one end at low tide, and from the other end by an exhausting steep climb and tricky descent. The boulders in this colony range from knee sized to van sized, and not all of them are stable! The birds nest everywhere within these boulders - underneath them, on top of them, and even burrowing into the shallow soil that is present in some areas. We placed bamboo canes near each nest with a tagged a bird, but despite this finding them again proved to be quite tricky.

Carnach Mhor

Unfortunately the weather delayed our outbound trip to the Shiants and so we had less time there than we would have liked – still, we got a good number of tags back from the birds showing where they had been foraging.

Next we visited Lunga, which is part of the Treshnish Isles to the west of Mull. We spent a lovely nine days here, with glorious weather and very friendly birds.

Lunga gets a lot of daily visitors, which means that the birds here are much more used to humans than any I have seen before, meaning they are easy to catch and to re-catch. Consequently we were able to deploy a lot of tags for the time that we spent here, with very good retrieval rates.

Lunga, Harp rock and Shag rock.

We camped on Lunga with the kind permission of the Hebridean Trust, but we had not banked on the number of nocturnal birds that would keep us awake at night! Storm Petrels nest in the boulder beaches and in the old buildings, providing a constant ‘purr’, Manx Shearwaters also nest nearby and at night come out of their holes to howl and chortle to one another, and the rhythmic ‘Crex crex’ of a corncrake continues consistently throughout. Once dawn had arrived and some of these birds had gone to bed, the skylarks and the starlings started singing.

Night time on Lunga.

After Lunga we returned to the Flannan Isles, which we recce’d earlier in the season. The Flannan Isles are fairly remote, and are about 2/3 of the way from Lewis to St Kilda. We arrived in style on a Catamaran and spent the week over midsummer cut off from the outside world, except for the VHF shipping forecast. After a week of no-one else’s company the lilting tones of Stornoway Coastguard announcing the weather held a surprisingly strong attraction, and we certainly missed it when we were off-island. The sea-pinks were in full bloom whilst we were here, and almost half of the island we were living on was carpeted pink.

Flannan isles pinks.

Puffins also have a large visual impact on the Flannan Isles. They nest here in such densities that their burrows seem to have destroyed the root systems of the plants that try to grow. There is not much space here for new burrows, and each that is built destabilises other birds’ burrows and results in an almost post-apocalyptic landscape of partially-collapsed burrows.

Puffin burrows.

Our next trip was up to Cape Wrath to work with the Army on their annual seabird ringing trip. Our aim was to recce a boulder colony below Col Mor (the largest sheer cliffs on mainland Britain) and deploy tags if it looked suitable. Unfortunately the weather meant there was only one trip out to the boulder colony, but we did deploy and retrieve some tags on Kittiwakes at their base at Faraidh Head.

Col Mor guillemots.

From Cape Wrath we made the lengthy journey down to Campbeltown, and ultimately to the island of Sanda, which lies a few miles south of the Kintyre Peninsula. On Sanda we were aiming to catch Tysties (Black Guillemots).

Tystie on cairn.

Unfortunately, for a combination of reasons we did not catch any birds on Sanda, so instead of progressing on to Haskeir as originally planned, we moved up to Orkney to work on a different population of Tysties. Tysties are smaller and harder to catch than the other seabirds that we work on, and we use special lightweight remote download tags to collect data. The tags communicate with a base station that we leave out overlooking club sites where the birds ‘hang out’, and when we connect our computer to the base station it downloads the data for us.

A tagged tystie.

We deployed the last of our tags on Thursday and have been returning to the island each day to download new data and to move the base station between the sites where we have tagged birds. The birds here seem to be doing very well, with individuals constantly flying in with large fish.

This Tystie work concludes our field work for the 2014 season. We now have a few weeks of packing up equipment, sorting out data and taking a well needed rest! Visiting and working on these islands has been a tremendous experience, both for the birds, the scenery, and the astonishing number of beautiful sunsets.