With the decline of natural nesting sites, putting up a nest box or two in your garden can really help breeding birds. To give birds and their chicks the best chance of survival, it’s important to put your nest box in a suitable location. Where you site your nest box will also depend on which species of bird it is intended for.
Birds traditionally start breeding on Valentine’s Day on the 14th of February, but many birds will have started looking for suitable nest sites long before then. Some birds, such as robins, can even begin building their nests as early as January, and juvenile birds may begin selecting potential sites during their first autumn and winter. Blue tits and great tits, the most common species of birds to use nest boxes start laying in April but spend one or two weeks building their nests and at least a month before that looking for the perfect spot, so the earlier you get your nest box up the better.
Ideally, have your nest box installed by November if you want it to be used the following year. This gives birds time to get used to it before the breeding season and provides a place of shelter for them to roost during the winter. However, you can put them up at any time before breeding season starts and may have success even if you wait until January or February. Remember, it can take several years before a new box is used, so don’t be disappointed if a bird family isn’t ready to move in immediately.
Although, you’ll probably want to place a bird box where you can watch the parents as they come and go with nesting material and food for their chicks, the number one priority is to place it somewhere that’s safe and secure and to minimise the risk from predators or bad weather.
Find a spot that’s in the shade of buildings or trees. If this isn’t possible then place the box so it’s facing between north and east, so it’s sheltered from the strongest sunlight and the wettest winds.
To help prevent rain from entering the nest box tilt the front slightly downwards so the rain will hit the roof and bounce off. Make sure there are drainage holes in the bottom before you hang it so any water that does make its way in doesn’t ruin the nest or even worse, drown the chicks.
To obscure it from view, attach the box to a wall or fence that has shrubs or creepers growing against it. Birds need a clear flight path to enter the nest box so the entrance hole needs to be free from foliage and anything else that could obstruct it.
Many species of birds aren’t too fussed about the height of a bird box; after all, in the wild, they have to use natural holes and cavities where they can find them. You might find birds who have built their nests in shrubs and bushes in your garden, and these are often surprisingly close to the ground.
Placing nest boxes between 1.5 and 2 m above the ground is about right. This will attract many of the most common species of birds and ensures the box is out of the reach of predators and the prying hands of inquisitive children. It also means you’ll be able to reach it easily to clean and maintain it at the end of breeding season.
Birds that use open-fronted next boxes such as blackbirds, robins, wrens, and pied wagtails prefer them to be a little lower at up to 1.5 metres above the ground, but make sure they are well hidden in vegetation such as a shrub or ivy to provide plant cover.
House sparrows and starlings often choose to nest under roof tiles so place their nest boxes high up, ideally under the eaves of your house if you can. House martins, swifts, and swallows, who nest in caves in the wild, also prefer nest sites situated up high and you can buy specially designed nest cups for them that can be fixed to the sides or walls or in outbuildings.
All these birds nest in loose colonies, so place a few nest boxes for them close together for the best chance of them visiting your garden to nest.
Woodpeckers, kestrels, and owls nest high up and don’t like being disturbed, so secure their boxes to the trunk of an isolated tree about 3 to 5 m above the ground. Make sure there is a clear flight path so they can access the box with ease.
Don’t use nails to fix your nest box to a tree which may damage it. Instead, use nylon cable ties or galvanised wire that will not rust outside. Remember that trees grow in girth as well as height so you will need to check the fixing every couple of years.
If there is plenty of natural food in your garden, then two boxes nearby may be occupied by the same species if they are at the edge of adjoining territories. But this is pretty rare, so you’ll normally only see one nesting pair of each species unless you’re attracting the birds that nest in colonies mentioned above.
Begin by putting up a couple of generalist nest boxes to see whether you get any interest. Don’t place them too close to bird baths or feeders as nesting birds don’t like to be disturbed.
In time, you could try adding some of the more specialised nest boxes depending on what species you have visiting your garden.
The more bird boxes you add to your garden in different places, the more chances you have of a pair of birds occupying one in which to bring up their family.
It can take a while for birds to move into your nest box, so even if it’s unoccupied for the first year, leave it in place for the next season to see if any birds begin to use it.
If they don’t, then move it to a different place to see whether that’s more attractive for them, and hopefully in time you’ll be welcoming a new family into your garden.