Caledonian Horticulture is regularly posting ideas for ways in which you can help boost biodiversity in your local area, from simple everyday changes to nature projects in your garden. Today we are discussing bird boxes
Why are bird boxes great?
Many of our native bird species struggle to find natural nesting sites, so installing a bird box in your area can be a great way to attract bird species and provide them with a home.
When can I put up my bird box?
Between February and September, birds will use nest boxes for the nesting season, however during the winter they may also be used as shelter from the cold weather.
Therefore, they can be installed at any time of year really, but autumn is generally considered a good time as they can provide shelter for winter and gives species plenty of time to investigate the box before the nesting season begins.
Where can I put my bird box?
Bird boxes can be installed in a variety of places including on trees, on garden shed walls, on the side of buildings, and in bushes. If you do not have a garden or outdoor area to put up a bird box, you can talk to your local council about areas in local parks where you can put up a box which you can visit.
Hole nesting boxes
These types of nest boxes are great for species like blue, great, and coal tits, sparrows, and starlings.
The size of the entry hole can vary to better suit different species:
- 25 mm – blue tits
- 28mm – great tits
- 38mm – sparrow
- 45mm – starlings.
These boxes need to be waterproof and so adding roof felt is a good idea, as well as having an overhanging roof.
Where should you put hole nest boxes?
Birds using these boxes prefer a clean direct flight line into the box. They need to be placed in a clear space and not deep in vegetation.
They need to be placed 2-4 metres above the ground. You may want to position them slightly forward tilting to help with rainfall. Boxes should be placed North-East facing direction. Do not position boxes facing south.
Do not introduce nesting material to the box. You may wish to leave straw or wool on the ground nearby for the birds to gather if they require it.
Open nest boxes
Nests with larger openings tend to suit birds like robins, wrens, and flycatchers.
They can be made from wood in a similar design to hole-nesting boxes, or some designs are made with steel, rattan, and brushwood to better reflect the habitat.
A box with a 100 mm high open front may attract robins and pied wagtails. A wren would need a 140 mm high front panel, while spotted flycatchers prefer a low 60 mm front to the box.
Bird boxes can be bought in stores and online, or instructions can be found online on how to make them yourself. The most important thing to remember if you decide to make them yourself is that they are made from untreated wood – larch is a great option as it is waterproof and so you do not need to add anything to the wood.
Where should you put open nest boxes?
These boxes need to be placed and secured in areas that are closer to the ground than hole nest boxes and tucked in with vegetation, such as ivy.
They need to be placed in well-concealed locations to prevent the eggs and chicks from being exposed to predators and bad weather. They can be placed in a tight spot like the fork of a tree or a hedge with plenty of coverage.
Robins like nest sites that are well hidden in the vegetation whereas spotted flycatchers prefer a more open site entrance, so they still have a good view outward to their surroundings.