Britain's Flags

Bird boxes for garden birds - Frequently asked questions

Some of the answers to these questions can be found elsewhere on this website, but it seemed appropriate to also address the issues here.

I don't have a garden. Is there any reason for me to have a bird box?

The countryside and natural nesting sites for birds are diminishing to make way for housing, roads and industrial development. By having a nest box fastened to the wall of your house or your flat you can create a safe nesting site for birds and help reverse the decline of some of our once common garden birds.

Which birds will use bird boxes?

Blue tits and great tits are the most prolific users of bird boxes in domestic gardens, although the RSPB has recorded over 60 species of birds know to have used nest boxes. Robins prefer open fronted nest boxes (hidden in vegetation, such as ivy) and it's possible to either buy or fabricate nest boxes for house sparrows, and other species including house martins, swallows, starlings, kestrels and owls. This site restricts itself to nest boxes for small garden birds.

Can you recommend any pre assembled boxes and camera kits?

I have a four page review of the HANDYKAM nest box and camera kit that you can view, commencing on this page. It's a very comprehensive kit and is realistically priced.

I would like to make my own bird boxes. What materials do I need?

Any rough wood, planking or exterior ply wood will be suitable. Try to use at least 15mm thick wood, to ensure better insulation. You can protect the exterior of the box with water-based wood stain, but do not use any wood stains or preservative inside the box or round the entrance hole. Fenceguard and Sadolin Classic (a wood stain, not a preservative) are recommended by the manufacturers as being suitable products for use on nest boxes. Cuprinol TimberCare (for use on rough sawn timber) is also safe to birds when dry. As with any preservative, do not paint the inside of the nest box or around the entrance hole.

Where can I find some bird box plans?

I have nest box plans for small birds such as blue tit and great tit, and also instructions on how to build a sparrow terrace.

How big does the entrance hole need to be?

A hole diameter of 25 mm will allow blue tits, coal tits and marsh tits to enter the box. Use 28 mm for great tits and 32 mm for house sparrows, tree sparrows and nuthatches. Blue tits will also use boxes that have the larger holes, but they may be driven out by the bigger birds. Great tits are not averse to using nest boxes with 32mm holes, in fact two of the three sections of our sparrow terrace were occupied one year by great tits.

Do I need a perch on the front of my nest box?

No. A perch simply gives cats, squirrels and other predators an extra foothold.

How can I protect my nest box from domestic cats?

Make sure that the entrance hole is at least 12.5cm from the floor of the box to keep the young chicks safe from predators and to minimize the chance of cats clawing out the tiny chicks. Rose cuttings or any thorny material on the roof of the box should discourage cats. If the box is mounted on a tree, ensure that there are no overhanging branches for the cat to gain easy access to the nest hole.

Woodpeckers have enlarged the entrance hole to the box and taken the chicks. How can I prevent this happening in the future?

Site visitor Anna Beswick, who had the same problem for two successive years, used a piece of aluminium sheeting across the front of the box and further protected the entrance to the nest box with an aluminium extension tube. If your nest box is shaded, or faces north, this should not result in an excessive temperature rise within the nest box.
See also this link for further advice.

When do I need to get the bird box in place?

Ideally, nest boxes should be in place as early as possible in the new year. Although most birds will not start building their nests until March, they spend many weeks making exploratory visits, checking out suitable sites, hopefully yours, and mine! If you get your nest boxes in place in the autumn, you may well attract winter roosters who will then consider their winter quarters a suitable location to raise their brood the following spring.

Where should I site my nest box?

Bird boxes should be fixed a minimum of 2 metres from the ground, either on a house wall or in a tree, in a quiet part of the garden, away from predators. Preferably site the box with the entrance hole between north and east. This avoids the worst of the weather and prevents the box and its inhabitants becoming overheated in sunny weather.

Do I need to provide any nesting material?

If you leave newly raked moss from your lawn in a part of your garden, the birds will take this as nesting material, along with other natural material you put out such as hair clippings, strands of wool or feathers from old pillows.

The birds are pecking at the entrance hole. Is it too small?

It's natural to think that the birds are trying to enlarge the hole. 25mm looks too small for a blue tit to get through, but believe me it is big enough! The RSPB suggest that the pecking may be a form of display by the male, and that the females peck at the hole to test the strength of the wood to determine if the box will make a secure home.

How can I help the birds once the chicks have hatched?

Mealworms, mealworms and more mealworms! Live food is essential for the development of the young birds. Sunflower seeds or hearts, summer bird food mix, insectivorous mix, mealworms, mild grated cheese etc. should all be fine to help a developing family. Remember - Whole peanuts can cause the death of young birds, so peanuts should always be placed in a metal mesh feeder. Peanuts, fatty foods and bread are not appropriate foods during the breeding season, but they are fine for the winter months.

Where can I buy mealworms?

Some specialist pet shops sell mealworms as live food for lizards etc. It's possible to rear your own, but it's a lengthy process. Dried mealworms are readily available, but soak them in hot water before putting them out for the birds. The water swells the mealworms and the moisture is important for the development of the chicks.

Why was my nest box not used?

Birds are so fickle! One year our box was home to a family of 11 chicks that were all reared successfully. The next year it was not used at all. Some bird boxes that are on sale are just not suitable, even though they may look appealing to humans. Many are too small and some are incorporated into a bird table. No self respecting bird would choose to have a house directly above a fast food restaurant! If the box is not used one year try moving it to another location - maybe a quieter part of the garden and away from bird feeders and other nest boxes. Also consider a higher location, out of the afternoon sun, moving it away from other nest boxes, and somewhere safe from possible predators.

Do I need to remove the old nest from the box?

Yes. Remove this at the end of the breeding season. Wait until late October or November in case the nest is used for a second brood. If there any unhatched eggs or dead chicks (sadly they might not all develop) then dispose of them. It's against the law to keep birds' eggs. Wash out the box with boiling water to kill off any parasites. The box may be used by roosting birds if the winter is harsh, so replace the box after cleaning it out.

Is that it?

I think so (!) but I will add to this list if necessary!