Sarah Harrison, long term Isle of May volunteer writes:
During the Second World War the May was an important outpost for the military, as it was used as an early warning station for enemy submarines entering the Firth of Forth. I like to think that some of the wartime spirit survives in the island’s modern role as a nature reserve, as we try to meet the challenges of managing the reserve with often limited resources.
One thing you quickly learn on the island is that there is rarely a tool designed specifically for the job you want to do and you often have to improvise! Usually this involves repurposing everyday objects, especially recycling things that would otherwise have ended up going off with the rubbish. Here are some challenges we faced managing the tern colony and the way we solved them…
Challenge 1: Every year some of the Kirkhaven terns, for reasons known only to them, decide to make their nests below the high-tide line on the beach. How do we stop them from getting washed away?
The answer is to create the tern equivalent of mobile homes, which can be gradually moved up the beach over several days in time for the high spring tides.
We take an old water carrier and saw the top off, which creates the ideal tern nest buckets complete with drainage hole. The bottom of the water carrier doesn’t go to waste either as this is turned into a normal bucket with the addition rope handles.
The tern bucket is filled with sand and then the tricky part begins, reconstructing the nest scrape on top of the bucket. The key to this is to find the identifying features of the nest e.g. recreating the lining and replacing any nearby rocks or seaweed.
We also bury the buckets into the sand for the first day before lifting them out and then gradually moving them, day by day, up the beach. The terns don’t seem to notice that their nests are creeping gradually away from the sea, and happily settle back on the buckets after we move them. In fact, we had the first bucket chicks hatch this week.
Challenge 2: Even the terns that choose to nest in sensible places live a pretty precarious existence, as the tern colony at Kirkhaven is surrounded by a gull colony. Every year a few of the gulls become specialist tern eaters, and if left unchecked can decimate the colony. In previous years the adult terns have abandoned and no chicks have fledged. How can we make predation more difficult for the gulls?
If you visit the May you will find that Kirkhaven colony currently looks like this…
It may seem like a strange cross between a pincushion and Glastonbury festival, but all the man- made stuff is there for an important reason.
Firstly, the garden canes act as a defence against aerial gull attacks. The terns are small and manouverable and can hover between the canes to get to their nests. The gulls can’t hover, so the canes stop them from swooping down through the colony and grabbing eggs or chicks.
The canes aren’t foolproof though, as some gulls have learnt that they can land at the edge of the canes and walk into the tern colony, so the bunting has been strung up at gull head height to put off the walking gulls.
Finally, the little wooden tents are there as shelters for the chicks. We put them up close to the nests so the chicks can run underneath them to hide from the gulls. The chicks seem to have taken to them, and are using them to shelter from the sun on hot days too.
Becky and I have the job of recycling leftover wood from the new visitors centre to make the shelters. With over 400 pairs of terns nesting this year we’re going to have a lot of sawing and hammering to do!
Hopefully all this improvisation it will all be worth it and the Isle of May terns will win their war with the gulls this year.