Blackbird breeding and colour mutations

IN SPRING, blackbirds are often quickly out of the traps, beaten only by the mistle thrush. Expect nest-building activity in late March.

You have to supply these birds with sloppy mud and a mix of materials – dried grasses and rootlets – so that they can build a very robust nest. They will lay four or five eggs per clutch and will produce three or four clutches per season. They tend to build a new nest every time, so make sure you supply a few nest-boxes for your birds to choose from.

Nest sites can vary tremendously, from flowerpots to old hanging baskets. The recommendation is to offer a 20cm x 20cm (8in x 8in) box, with a roof and a wire floor. The front