Crested grebes making a nest together

Though I think they've chosen the wrong place to do it. They were working very hard gathering weed and sticks, but I don't think the foundation is strong enough to support a nest, and it certainly isn't in a place they can nest in peace. It may be a first effort, as another pair have nested nearby for years, and seem to be still there.

The weather is so dark and grey, it would be lovely to have some light to photograph them, but they probably won't be there when I go back so it had to be today.