KINGFISHER NEST?

Just returned back to the office after one of my little strolls along the river.
Spotted a KIngfisher behave quite strangely, and fly straight into a thick lilac bush, behind a fence on an island in the river. The Island has an unoccupied wooden stilted house on it (owned by the EA).
I have no idea why this Kingfisher flew into this bush behind this fence - it certainly wasn't fishing from the bush.
But is it too late for nesting? Possibly not in the case of Kingfishers; its just about the end of the spawning season now (hence the closed season on the rivers), so there'll be plenty of fry and small fish around to keep any chicks fed.
I'll keep an eye on the bush (from my side of the river), and if necessary, obtain permission to go onto the island and see what I can find...