It’s April again and already some birds have started nesting, so I’m going to show you how to make a bird nesting box but if you haven’t yet put up your your bird boxes you may now be too late for this year. The birds have to be familiar with nest boxes before they will consider them for use when they start looking for nesting sites, so it’s best to make sure that any new nest boxes are in place before March is over, or earlier if possible. So I’ve made a couple of videos to show you how to make your own bird boxes ready for next year.
To make them you need to have some DIY skills and also a few tools. If you have these attributes there is no reason why you can’t make a perfectly good bird’s nest box.
If you didn’t clean out the nest boxes at the end of last year you should think about doing it now to get rid of any mites, fleas and old nesting material, otherwise this year’s chicks may become ill and die from infections. Give the birds nesting in your bird boxes the best chance of survival.
Now is the time to put up new bird boxes. (Jan/Feb)
If you haven’t already got any bird boxes in place, now is the time to think about putting some up but you’ll need to know a bit about what the birds want and what kinds of nest boxes different birds require. For example; some garden birds like to nest in holes and some like to nest in open boxes, but others likes thrushes and blackbirds won’t nest in anything you make. So, if you ‘re going to make some boxes yourself, here is some information to help you make the kind of nest boxes which are likely to attract the birds.
Bird boxes for hole nesting birds.
As birds come in different sizes, so the hole size in your nest box will determine which birds can get in. If you want just anything to nest in it then a 45mm diameter hole will do just that, it will let in all the tit family and also house sparrows and even starlings. But you will probably find that smaller birds won’t try to nest in it as they will get evicted by the bigger birds. A hole this size may also allow squirrels and even woodpeckers to enlarge the hole and get in and raid the nest taking any eggs or chicks inside. So, you can be selective by reducing the size of the hole.
Making a nest box.
If you have some woodworking tools and a little DIY skill you can make your own nest boxes. If you want them to look nice and neat you should make them using wood that has been planed smooth (PSE) but that will cost you more than making them out of unplanned wood (rough sawn or just sawn). The birds won’t be bothered either way but in my wildlife garden I like things to look natural so I use sawn. For small birds like blue tits, coal tits and marsh tits the floor size can be as little as 100mm (4”) square but no less. This is quite handy because you can make the box out of a piece of wood 160mm (6”) wide and 25mm (1”) thick which is a standard size. Any bird boxes for bigger birds will be a little harder to make because you need a bigger floor area which means using different sized pieces of wood. You can cut the entrance hole either in the front or at the side and adding a perch outside the hole is optional, but I’ve noticed that the birds do use them so I would recommend including one.
The bottom of the hole should be at least 125mm (5”) above the bottom of the inside of the box so that anything inside is out of the reach of squirrels and cats. More than 5″ is even better.You need to make the roof sloping for rain to run off and it should overlap the front to stop rain blowing in through the hole. There must also be some way for you to get into the box and the preferred method is a hinged roof, although you could have a piece of the front which will come out. This isn’t so that you can annoy or even frighten off the nesting birds by constantly looking inside to see what’s happening, it’s so you can get inside to clean it out later in the season and remove all the nesting material, lice and mites of which there will probably be plenty. Don’t be tempted to do this when you have just seen the first chicks leave the box as the parents will often use the same box to have a second or even a third brood. You can make a hinge for the lid using anything flexible and strong enough to not tear during the season, I use ‘damp course’ membrane which builders use which comes in rolls and can often be bought from car boot sales for a few pence. To fix the pieces of the box together you can use screws or nails but make sure the nails are galvanised and the screws zinc coated; that will extend the life of your bird box as they will not rust and cause it to fall apart. A most important thing to remember is to drill a hole in each corner of the base inside so that any water (rain) that gets in can drain out so the box doesn’t fill up with water and drown the chicks.
If you want to see exactly how to build your own birds nesting box you can watch me make one on one of the videos at the top of this page.
Here are the dimensions of all the parts: The nest box is made out of a plank of wood 1.3 metres (51” approx) long x 150mm (6”) wide x 25mm (1”) thick. These dimensions only apply to rough sawn timber as planed timber is slightly reduced in size in width and thickness because of the wood removed in the planning process.
Bird nesting box with lift up top:
Back 355 14
Top 190 7½
Sides 230 to 180 9 to 7
Front 180 7
Base 150 6
Bird nesting box with inverted V shaped top:
You don’t have to use these sizes but they will save you having to work them out for yourself. The important measurements are minimum floor size 100mm (4”) x 100mm (4”) This size box is only suitable for small birds like blue tits and coal tits. If you want to attract larger birds like great tits, house and tree sparrows, starlings and nuthatches you will need to build a box with a larger base area and also the hole will need to be bigger; see the hole sizes below.
25mm for blue tits, coal tits and marsh tits.
28mm for great tits, tree sparrows and pied flycatchers.
32mm for house sparrows and nuthatches.
45mm for starlings.