Wednesday, May 09, 2018

What's happening on the island?

We've been hard at work on the island trying to improve nesting options for Common Terns and Sand Martins. Last year the new Tern raft we put out near the island was a great success with Common Terns taking to it straight away and successfully raising several chicks. Other Terns also appeared to nest on the island even though the habitat is not as conducive for nesting. Terns create a small scrape in which to lay eggs so a gravel base is ideal, like that on the Tern raft. We decided to add an area of gravel on top of the concrete block to expand the available area for the terns to nest. Several boat trips were made to the island to get the materials out there and a layer of membrane and a couple of inches of gravel was laid down. This has a dual benefit in that, as well as providing an ideal nesting area for the Terns, it prevents unwanted plants growing. Initial signs are good as Terns appear to be making use of this new area in good numbers.

Common Tern - (c) Andy Croft
We have also replaced the old Tern raft with a new one. One of the canisters used to keep the raft afloat had sprung a leak on the old one. Amazingly, having positioned the new raft, a pair of terns checked it out when we were only a few feet away!

Deploying the new tern raft - (c) Andy Croft
The concrete block also provides nest holes for another summer migrant, the Sand Martin. In the last couple of years work to cut back plant growth in front of the block has helped the Sand Martins use the block for nesting culminating in successful breeding last year, as far as we could tell. This year we have added membrane and gravel in front of the concrete block to prevent plant growth. As soon as the Sand Martins returned this year they immediately started checking out the nest holes so we are hopeful of successful breeding again this year.

Sand Martin

While out on the island we also carried out the annual Canada Goose egg oiling program which aims to keep the Canada Goose population in check. This year we carried out 2 visits to the island for egg oiling, on the first we oiled 93 eggs in 17 nests. On the second visit we oiled 139 eggs in 28 nests.

Canada Goose

Egyptian Goose

Greylag Geese
There are 2 other species of goose nesting on the island, Greylag and Egyptian but these are currently in much smaller numbers than the Canada Geese. Ducks also nest on the island in the form of Mallards and possibly Tufted ducks and Gadwall. We think that Oystercatchers may also nest on there but have no hard proof so far despite them regularly hanging out on there.