Country Diary: Loch Ruthven

Sitting in the large, comfortable hide on the edge of the loch, a few miles south of Inverness, the scene looked idyllic. Willow warblers were singing from the birch woodland that was turning green as fresh leaves unfolded. A mallard duckling was scampering amid the growing sedges below the hide, although the duck was nowhere to be seen. Common sandpipers trilled as they flew over the water and around the hide toads were croaking.

Way out on the water were the birds of the moment; iconic Slavonian grebes were displaying before choosing their breeding sites in the fringing sedge beds. Seeing these attractive birds in such a setting it was hard to believe that there is a mystery about them that nobody seems to have solved. The problem lies in the fact that very few young grebes are brought off each year. Last year was worse than usual with only 36 pairs, all in the Highlands, which is the second lowest since monitoring began in the 1970s, and only 10 young fledged.

Loch Ruthven is a stronghold for the birds, and in 2007 there were 19 pairs, which is within the normal range, but only three young fledged. Cameras were at one time installed near nests and predation of eggs was found to be by crows, gulls and stoats. This was expected; what was not expected was the film of an otter taking an adult grebe off its nest. Fortunately no mink or pine marten were seen, although they were not far away.

On other lochs in the area introduced pike are a threat, but fortunately there are none of these predatory fish in Loch Ruthven. The other threat is the weather, as strong winds form waves that occasionally destroy nests. Unfortunately the weather is the one aspect we cannot change.