17 February 2016

Making a home for my ‘tweet’ Valentine

Hazel Evans, Nest Box Challenge Organiser writes:

There is still a chill in the air, but at last the days are getting longer and it’s time to think about where our local birds will be nesting this year. Valentine’s Day sees the start of BTO and Jacobi Jayne’s annual ‘National Nest Box Week’. The aim of the week is to encourage and promote the putting up of nest boxes in your local area.

There are numerous reasons why I advocate nest boxes and it can be as easy as you like to take part. The simplest thing you can do is to go to your local garden centre and purchase a suitable Nest Box and put it up in your local area. This may be your garden, but if you are looking further afield, a local park or woodland is also great (as long as you have the land owner's permission). As old trees fall or are cut down, houses are better insulated and gaps under the eaves are sealed, there are fewer natural cavities available for nesting birds so providing artificial nesting locations is extremely valuable.

Robin in an open fronted nest box. Photo by John Cranfield

Once you’ve put up your nest box - or filled your local park with them - monitoring is where the real conservation value lies. Nest boxes give us the opportunity to easily collect data on the breeding success of cavity nesting birds; the same data can require a little more time and skill to collect from natural nest sites. As long as the NRS Code of Conduct is adhered to, we can safely record the progress of nesting attempts by looking inside next boxes to count the number of eggs and chicks and submitting data to the Nest Record Scheme (NRS). There is a very large body of research showing that the contents can be examined without any negative impacts on the outcome of the breeding attempt.

NRS participants monitor nests by inspecting them at intervals and recording the number of eggs laid, the number of chicks hatched and whether chicks fledge successfully. This information is used by the BTO to study the breeding performance of wild birds to help identify when reduced productivity might be causing population declines. People can be concerned about opening up a nest box and checking the contents, but done in the correct way the value of the data collected is huge.

Blue Tit chicks. Photo by Simon Thurgood

By far the most common inhabitants of garden nest boxes are Blue Tits and Great Tits. They have adapted so well to living in our man-made constructions that we receive thousands of nest records for these species every year. These records provide such good national coverage that it is possible to explore the degree to which birds' responses to changes in the environment vary between regions and habitats.

At the other end of the spectrum are Treecreepers, which have so far not adapted to using nest boxes. A nest recorder recently developed a design which mimics the thin, natural cavities preferred by Treecreepers. If you would like to have a go at making one of these boxes then please do let the Nest Record Scheme know whether the box is used or not. If it is used then you can also submit a nest record.

Treecreeper. Photo by John Bowers

A huge variety of nest boxes are available to either buy or to make and you can find information to help you choose an appropriate box on the National Nest Box Week website. When choosing a box it is important to make sure the lid can be lifted or removed to allow you to monitor the contents (or that you can appropriately modify it) and that it is well constructed from a thick enough (and appropriate) material to protect a clutch of very small, very vulnerable chicks! Building a box can also be very rewarding and save a lot of money.

Nest boxes can of course be put up at any time of year but winter is ideal as it provides time for prospecting birds to find the site before the breeding season. Once used, it is a great idea to clean out old nests the following winter to allow for a fresh start in the spring. To comply with legislation, nests can only be cleaned out between 1 August and 31 January.


  1. Our nest box under the eaves of the roof has a blue tit roosting every night now. Hoping it finds a mate this Spring.

  2. So how is safe monitoring done. I can only imagine e using a narrow-handled mirror as my RSPB n'est box opens at the side.