Bird Boxes- How to Choose

//Bird Boxes- How to Choose

Bird Boxes 

Why do we need bird boxes?

Bird boxes are becoming increasingly important in our woodlands, as deforestation is causing rapid loss of suitable nesting sites. Loss of habitats can have devastating impacts on breeding birds, particularly those who nest in the same site year on year. Birds who nest in the same site are also at risk if they choose to nest in old buildings, as these sites disappear upon building repairs. For example, swifts often nest in spaces under the eaves of old houses and churches, this allows the bird to drop into flight straight from the nest. When these buildings are repaired those vital nest sites are lost, causing a huge problem for swifts, which pair for life and meet their mate every year at the same nest site. 

Bird boxes help maintain UK bird populations by supporting breeding pairs. These breeding birds are needed to maintain the fragile UK ecosystems in which all native bird species play a role. The decline of one species can cause catastrophic impacts on other plant and animal species that rely upon them in the food chain or from other ecosystem services, as well as further impacts on the environment if pollinating birds are lost.

Different types of bird boxes and important facts about some nesting birds

There are two main types of bird boxes that are suitable for different species of birds. The first is an open-fronted nest box which is preferred by robins, wrens and kestrels. The second is the more common small holed nest box which is preferred by tits, sparrows and starlings. 

Within these two main types of bird boxes, there is a huge variation in sizes of both entrances and boxes which are all designed to suit individual species of bird. Information on these sizes can be readily found online and it is important to research this before deciding on which bird boxes to install. It is also important to note that boxes designed for different species must be placed in different locations and altitudes.


Open-fronted nest box                                                         Small holed nest box

Furthermore, some additional box designs exist for birds with unique requirements. Swifts come to the UK in the summer to nest, however, their numbers are dwindling partly due to a lack of breeding sites. These incredible birds require unique looking nesting boxes, allowing them to easily swoop in and out of the nest, adhering to the swifts’ physical design and nature. Little owls require quite fancy bird boxes, preferring large open-fronted boxes which will ideally contain a smaller room perched underneath for their young.


Bird box designed for swifts                                                         Bird box designed for little owls

Barn owls require specific and unique requirements for bird box placements. Since barn owls are very sensitive to disturbance, it is best to place boxes in quiet locations where humans rarely visit. (It is against the law to disturb nesting barn owls as stated in the 1981 Wildlife and Countryside Act.) Furthermore, since male and female barn owls roost separately, placing boxes in pairs will provide a breeding pair with a roosting and nesting site. Barn owl boxes are designed differently if they are going to be placed indoors or outdoors. Exterior barn owl boxes are designed as an A-frame and can be fixed to trees or the outside of a barn. If possible, they should be facing a grassland with a relatively open flight path towards them. Since barn owls are common victims of road accidents, it is best to place boxes away from main roads. Interior boxes are square-shaped and can be placed within barns, preferably away from the entrance. 

   Exterior barn owl                                                          Interior barn owl box                                                     

Holes for blue, coal and marsh tits should be 25mm in diameter, whilst they should be 28mm for great tits. Smaller tits nesting in a box with a 28mm diameter entrance may be kicked out by great tits, so it is important to have many 25mm entrance boxes. The box should be placed 2-4 meters high to attract a tit, facing North-East. Entrances to house sparrow boxes should be 32mm wide and those for starlings should be 45mm in diameter. House sparrows and starlings will readily use nest boxes placed high up under the eaves. Since these birds’ nest in loose colonies, two or three can be sited spaced out on the same side of the house, in house sparrow cases they can even be attached to each other like terraced houses! Keep these away from areas where house martins normally nest. 

         Blue tit bird box                                                                 House sparrow terraced bird box  


If you want to attract the desired bird to your box, you must not only focus on box design but also the correct bird feed and available food sources, as different birds require different feed. For example, black sunflower seeds attract greenfinches and tits, whilst goldfinches’ favour Nyger. It is important to know which food is favoured by the bird species you wish to nest in your box, but also the drawbacks of said feed, as some may attract unwanted competitors or pests. The feed may also contain other drawbacks which must be known and combatted. For example, black sunflower seeds leave large amounts of husk which contain toxins that can inhibit the growth of some plant species. Another example can be seen in peanuts, which can contain aflatoxins, a naturally occurring poison that is deadly to birds.

You must also choose the correct bird feeder for the desired species. You must know which feeder is preferred by your desired bird, but also the competitors it may also attract. For example, ground feeders attract birds such as thrushes, robins and wrens, but also larger competitors such as pigeons. Birds at ground feeders are also a threat to predators such as cats and carnivorous birds. To combat this, a ground feeder protector cage can be installed to allow smaller birds to safely eat.

Cameras in bird boxes

Modern technology has made it easier than ever to install cameras into your bird boxes and watch your family of birds grow! Furthermore, these cameras are silent and have no impact on the bird’s day-to-day life. 

When choosing the right camera for your bird box, there are a few considerations you must make. The first of these is price, with the cheapest cameras starting around £30 and increasing with price as they do with picture quality and reliability. The second consideration is where you would like to watch, as cheaper cameras can be viewed on the TV or computers, but more expensive cameras often possess a smartphone app. Finally, you must choose between a wired or wireless camera. Wired cameras often offer better quality and reliability for a reduced price, however, add the inconvenience of wires in your woodland, and for this reason, most would recommend wireless.

Wi-fi cameras provide reliable HD images without the risk of interference seen in traditional wireless cameras. Wi-fi cameras will be connected to an app, allowing you to watch your box from smartphone, tablet and computer. If your wi-fi does not reach the box in your woodland it is not to worry, as wi-fi extenders are an effective and affordable solution. Wi-fi cameras are the favoured choice by many in the current age.


If not done correctly, birds may not be attracted to your box. We have discussed the actual design of the box, but the box must also be in the correct location. Different birds have different preferences. For example, a kestrel box must be at least 5 meters above ground level and placed on an isolated tree or pole. Furthermore, the boxes entrance should be facing North-East to avoid strong sunlight and wet winds. Birds will always look for the safest place to nest, so place your nest far from the vicinity or easy access of mammillae such as squirrels and cats, and if you wish to attract smaller birds consider placing it within the relative camouflage of vegetation.

An unfortunate fact about bird nests is they are prime targets of many mammal and bird species, who prey upon the eggs and young birds. Common egg stealers include squirrels, rats, snakes and a range of bird species, most commonly corvids. The risk of predation to your bird box can never fully be eliminated, besides the raiders do need to eat to maintain the food chain, but you can take measures to reduce this risk. As mentioned above, placement is important. Locating your box over thorny bushes may deter mammals from climbing to the box, or alternatively, you can place metal wire meshing around or below the box. Mount the box at least 2 meters from the ground and away from overhanging branches. For smaller birds, make sure the entrance is small enough so larger predators cannot enter and consider using metal nest box plates to prevent predators from scratching and increasing the size of the entrance. Alternatively, plastic tubes can be added to the entrance to deter large predators. Do not add perches below the entrance, as these make predatory access easier. Finally, an overhanging roof on your box will prevent animals from sitting on top of the box and reaching in and make access from above harder.

What to do this December

It’s the right time to plant trees and hedges taken

straight from the field. They are normally called

‘bareroot’ as opposed to ‘container grown’. They are

half the price and settle in nicely into the cool moist


It is still ok to order and plant bulbs. The soil is still

very warm even if the air isn’t.

You can prune heavily sapping trees like Birches now and

Grape vines before the winter sets in.

Harvest the rest of your root crops and lift and store your

Dahlia, Canna and Ginger Lilly bulbs.

Don’t worry if your garden looks messy. The more mess the

better for wildlife that needs a place to hide away during

the winter. You will have plenty of time to clean your beds

in Spring. Just think- Your laziness now is creating a 5 star

hotel for wildlife.

However where needs must, continue to rake up leaves and

store them separately from the summer’s grass clippings as

they need a different process to break down quickly.

What to do in December

It is hard to advise indoor activities in this time. Check at Xmas Fairs- Horsham Sunday Xmas market, plus the Ukfield Festival of Xmas, Arundel by

Candlelight and ice skating at the Brighton Pavillion are just a few things to do – Covid dependent!

By |2021-11-26T12:58:12+00:00November 26th, 2021|Articles|Comments Off on Bird Boxes- How to Choose

About the Author:

In 2006 I formed Glorious Gardens, gathering together skilled practitioners to offer not just design but implementation of these designs and maintenance packages where we could look after the gardens once we had created them. Throughout my career I have designed gardens to inspire people with the heart aching beauty of nature, with shapes, colours, moods and proportions to pleasure the body and calm and delight the mind. I am also an artist who works with colour and abstract shapes and I bring this sensitivity to the 4 dimensions of a garden. I am very good at listening to clients and I’m able to draw out the essence of what a client wants for their outdoor space.