Starling Puzzle

Walking past the rear of the station buildings at Todmorden this evening, I became aware of an adult Starling stood on the wooden gutter. There was calling from the presumed nest site behind it, a cyclical chirping a bit like a Goldcrest singing. I have heard this many times and assumed it was nestlings, but this seemed so early in May I began to wonder if it was a call from an adult sitting on the nest?

Funnily enough, the Starling nest a few doors up the street delivered exactly the same calls. Is my memory adrift, or have we just had an early breeding season this year?