Nest Building

Caught her going in with Silver Birch twigs in her beak but they didn't show up at all against the background. So, using this one as she came back out again.
The Wood Pigeons have been nesting in our garden for years, along with Blackbirds and last year a pair of Magpies too. I've recently seen a Robin with nesting material in it's beak but no idea where the nest is being built.