This week the Biodiversity Team were at Whitehall Museum in Cheam discussing homes for wildlife and helping visitors build their own bird box.

Bird boxes are a great substitute for holes and cavities in trees, especially in areas that have had dead branches and trees removed. In many areas such as gardens, parks and young woodland there may be a bountiful supply of food for small birds but few nesting holes available. Providing bird boxes can really help breeding garden birds, and it is estimated that every year around 2 million fledglings are reared in bird boxes!

blue tits entering a nesting box

Blue tits entering a nesting box. Photo © CJ Wildbirdfoods Ltd

There are over sixty species of bird in the UK that use bird boxes, including familiar garden species such as blue tits, house sparrows, starlings and robins. However, there is no one bird box that fits all birds, as different birds require different sized boxes and different designs. Smaller birds such as blue tits, coal tits, house sparrows, tree sparrows, nuthatches and pied flycatchers will use small boxes with holes. Larger birds such as swifts, starlings and greater spotted woodpeckers will use large boxes with holes. Alternatively, robins, pied wagtails and spotted flycatchers prefer to use open fronted boxes.

If you want to put a bird box in your garden, it is recommended to build a small nest box for tit species or a small open fronted box for robins, as these are common garden species. Where you put your bird box in the garden is actually really important. Ideally they should be placed away from the prevailing wind and out of the strong midday sun, facing north-east to south-east. The best time to put a bird box up is around this time of year, as this is when birds will explore nest boxes to look for a good place to roost or feed from. If a bird box is placed in a good location and there is a plentiful supply of food, birds will often come back to use the same box that they nested in again in the spring.

At the end of the breeding season, in autumn, the bird box should be cleaned out with boiling water, to remove waste material and parasites that live off the birds. This means the box will be fresh and ready to use again for the next set of roosting birds. It’s also important to remember that bird boxes shouldn’t be place too close together, as many birds are territorial and will compete for space and food. The same goes for placing bird boxes near feeders or bird tables, as conflicts can ensure.

Robin nesting in an open-fronted bird box. Photo: © Focus Optics

Once your bird box is up you should keep an eye out for any activity. If a bird decides to nest in your box there should be plenty of action to see around spring time, when the breeding season starts. You can also monitor your bird box by taking part in the Nest Box Challenge, run by the Bird Trust for Ornithology (BTO), a nationwide survey that helps gauge the breeding success of birds in green spaces.

To get started check out this helpful information sheet on how to build your own bird box!

Eleanor Kirby-Green

SNCV Biodiversity Assistant

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