Boxing clever

I hope you all had a very happy St Valentine's Day and felt the love in abundance.

And it means that it is also time to spread that affection to garden birds because this is also National Nestbox Week

I had a really interesting discussion with a friend recently about how many boxes you should put up in a garden. The answer is there isn't an absolute answer, but it is definitely more than one!

The first reason for this is that different bird species use different types of nestbox. If all you have is a box for a Blue Tit, that means no box for your House Sparrows, Starlings, Swifts, House Martins, Robins and Wrens. So a good starting point is if you have a box for one species, put up a different one for another.

But can you put up more than one box for the same species?

Well, some of our hole-nesting species are colonial or at least semi-colonial - they don't defend a large territory and they like to have others of their own kind around them. So, for Starlings, Swifts and House Sparrows, put up several if you have room for them. They shouldn't be right next to each other - give them a metre or so for House Sparrows (as with mine below) and perhaps rather more than that for Starlings and Swifts.

But House Martin cups can be lined up alongside each other - just look at this natural colony I photographed in Spain.

It does mean that there is evidence that House Sparrow terrace boxes (where you get three-in-one) are rather too close for comfort. Yes, they will occasionally work, but three separate boxes are likely to be more successful.

It is also worth having more than one box for Wrens, too, because each male will build several nests for his mate to choose from.

With tit boxes, there is a risk that too many boxes will mean that two or even three pairs try to nest in your garden and end up having frequent territorial clashes, which can be exhausting for the pairs involved. However, in a prime woodland habitat, there will be holes galore, and birds do like to have choice. It means that they can pick the box that they feel safest using.

You can find the RSPB's full range of nestboxes here.

With all nestboxes, siting them is all-important. Remember:

• Follow the 'between north and east' rule if the box is in an open position
• Tuck Robin and Wren nests in behnd thick vegetation - they are very unlikely to use one that is in clear view

• They should be in a place that is safe from cats.
• They should be well away from feeders. Always avoid a bird table with a box in its roof - that's an instant recipe for a very hassled breeding pair should they try to move in.
• Only put boxes up if you feel safe doing so. Swift and House Martin boxes are best placed under the eaves with a clear flight line in, so that will require confidence up a ladder.
• Be careful if attaching a box to a tree, for the sake of the tree. Sometimes you will see advice to strap it to a tree, but that can be more damaging and constricting to the tree than one or two screws or nails. If using the latter, make sure they are stainless steel, and whatever your means of attaching, check at least annually.

Oh, and if you do have multiple nestboxes, don't expect them all to be used.

But do consider going out on a limb! I have several larger nestboxes in my garden for Stock Doves, Jackdaws and - if I'm really lucky - Kestrels. But it does take my friendly tree surgeon to get them up there for me!

And finally, when talking about nestboxes, don't forget that only some of our common garden birds use them, so think as hard about where all the other birds will nest. Blackbirds, Song Thrushes, finches, Dunnocks, Long-tailed Tits, Goldcrests... Think of planting a shrub or tree or climber or building a stick pile as effectively putting up another birdbox, and now is exactly the time to do that, too!