Nest box essentials
Whether you’ve bought or built your nest box, here are some top tips for putting it up and looking after it so that it can provide good quality housing for years to come.
Siting your nest box
Where you put your box is every bit as important as what it looks like. The highest priority when siting a nest box must be to provide a safe and comfortable environment in which birds can nest successfully.
- Spacing. Even small gardens will have space for a nest box, and larger gardens may have space for two or more. Nest boxes of the same type should not be sited too close together as this may promote aggressive behaviour between neighbours.
- Direction. Ensure your nest box is sheltered from prevailing wind, rain and strong sunlight – these factors are generally much more important than the compass direction in which the box faces.
- Shelter. The front of the nest box should be angled vertically or slightly downwards to prevent rain from entering the nest box.
- Height. Small-hole boxes (for species such as Blue Tit and Great Tit) are best sited 1-3m above ground on tree trunks, but avoid sites where foliage obscures the entrance hole. If there are no trees in your garden, the next best option is to place your box on the side of a shed or wall. Remember that you will need to reach it to check the contents and remove old nesting material. Species such as Robin and Spotted Flycatcher, which nest in open-fronted nest boxes, prefer sites that are hidden from view, so attach your box to a wall or fence that has shrubs and creepers growing against it. The height of the box is less important than the amount of cover - Robins can nest close to the ground or high in ivy.
- Predators. When siting your box, consideration must always be given to ensure that it is not easily accessible to predators (cats and squirrels). Unfortunately, this can be quite difficult!
- Protection. Fitting metal plates around the nest box entrance hole is one preventive measure that can be used to deter squirrels from gaining access. These plates are available commercially and can be purchased from any good garden centre or bird care company at very little cost.
- Feeders. Never place a nest box near to bird feeders or bird tables as high levels of activity of visiting birds could disturb nesting pairs.
Erecting the box
Make sure that you put your box up as soon as you build or buy it – the longer it’s up, the more chance it has of attracting visitors
- Attachment. Use galvanized or stainless steel screws or nails that will not rust. If fixing boxes to trees, galvanised wire can be used to tie the box to the trunk or hang it from a branch. Make sure to regularly inspect these fittings to ensure the box remains securely attached.
- Timing. Traditionally, nest boxes for small birds are put up in the spring. Pairs begin to prospect in the latter half of February, so a box put up at the end of the winter stands a good chance of attracting nesting birds. However, it is never too early or late to put up a nest box, as some birds will use them to roost in during the winter months.
While we can increase the probability of a box being used by choosing a suitable location, there are many factors that we don’t know about, such as the number of pairs of birds in the area, the presence of natural nest cavities nearby and the location of territory boundaries. Therefore, while some boxes may be taken up immediately, others may remain vacant, often for no apparent reason. Be patient, but if a box is not used for several years in succession it may be worth resiting it.
For other types of nest boxes and further information, see the BTO Nestbox Guide, which is available as an online purchase.
Cleaning Your Nest Box
When the breeding season is over, old nests can be removed and the box cleaned out. Bird protection law permits the cleaning out of nests between 1 August and 31 January. Any dead eggs must be destroyed promptly and cannot be kept or sold.
Some hole nesting species, including sparrows, may have second or third broods in the same nest. The nests of these species should be left until the end of October and then only removed when it is certain that they are no longer in use.
When cleaning out nest boxes it is advisable to wear surgical gloves and a dust mask. Old nests may harbour fungi growing on damp nest material, which can cause respiratory diseases. Nests can also house a variety of parasites such as fleas, lice and ticks. It is best, therefore, when removing the old nest to put this straight into a plastic bag and seal it before disposal.