The garden is busy with birds, large and small, flitting about the branches of the trees and large shrubs, peeking in to conveniently sized niches and crevices or picking out the perfect little twigs and small branches to fit into their planned constructions, searching for moss and lichen and dropped feathers to soften the interior of their chosen cavities or nests for the eggs and chicks soon to be laid within. Amongst them are the crevice-nesting Blue tits (Cyanistes caeruleus), lots of them, chasing each other, singing out their partnership claims, advertising their personal charms. I’m convinced, but did you know (thanks to the Woodland Trust website for this interesting snippet):

Like all birds, blue tits can see ultra-violet light – the front of their head glows brightly under UV light, and this is how females are thought to choose their partners.