Chasing terns

We went down to Amble Marina to meet up with Graeme and Dave, who had brought their RIB "Moby" from Beadnell Bay in a choppy sea. Kitted up in dry suits we ventured out into the North Sea to try out the survey methods.

I should explain what it is we're trying to do.

We need to design protected areas for five tern species around their most important nesting sites. There are too many important colonies in the UK to individually taylor a boundary around the most important feeding sites for each, so we are having to come up with some generic rules for where to put the boundaries, based on studies at a few key colonies. We've had some success with predicting where other seabird species feed based upon the habitats they use, and we want to use the same techniques on terns. We can look at the habitats used by terns by following nesting birds as they leave the colony and pinpoint the exact spots where they catch fish. If we can work out the habitats at each of these spots, we can build up a picture of the places they use, and the places we should protect, based upon the locations of their preferred habitats.

There are four teams doing this study this summer in Anglesey, Northern Ireland, Firth of Forth, and our team in Northumberland, concentrating our efforts at Coquet Island. This island is low and flat with abundant vegetation and lies about 1 mile off the coast near Amble. From a distance, it looks like an oil tanker, with the lighthouse appearing like the accommodation block on the ship. Large numbers of Sandwich, common, Arctic and roseate terns nest on the island.

Is it a ship? Is it a supertanker? No, it's a tern colony!

So how did we get on? Not very well. We sat in the RIB, bouncing about in quite a rough sea (seastate 3 - 4) until we could spot a Sandwich tern leaving the colony to travel in a direction where that would be smooth enough to follow it at speed. The first bird outstripped us easily, using the following wind. We tried with two more birds, but each time with Graeme taking the RIB as fast as he could, the Sandwich or Arctic tern gradually pulled ahead until it was lost from sight. We tried with an Arctic tern returning to the colony (upwind) and fared a bit better, but still lost the bird. We finished the day with following a couple of Sandwich terns that were actively searching. This was easier, as the birds were flying slower, but faced some extra problems with birds getting lost in a feeding flock.

"I can go faster than you!". Sammy the Sandwich tern

So we returned to the marina, feeling dispirited about what it would take to follow terns from the colony given the prevailing conditions at sea. We took a look at the weather forecast for the next few days, and realised that it was going to be a rare event when the sea would be calm enough for us to follow birds from the colony to their feeding areas.

The weather was forecast to be slightly worse the next day, so we cancelled Graeme for the day, so he could get on with other work.