You know Rusty, I think this is a recording from the end of last
year's season, ie when the chicks and Laddie had left, because
if you look well, you will see the deep, hollow shape of the nest,
hollow enough for the eggs and later the chicks.
It could date back from September/October, whenever they left.
And also they changed the picture/recording, before they were
showing some recording made on 16th March this year - as
JG and myself have mentioned - different shape.