WHEN AND HOW TO CLEAN BIRD NEST BOXES

DO I NEED TO CLEAN MY NEST BOXES?

Our wildlife and conservation charities recommend cleaning nest boxes to reduce the number of ectoparasites in the box the following year.

The benefits of doing so aren’t as straightforward as they seem; I’ve posted a run-down of the science here to help you decide whether and how often to clean your nest boxes.

WHEN SHOULD I CLEAN NEST BOXES?

If you do decide to clean your nest boxes, you must not disturb them between March and the end of August – this is breeding bird season. Do not attempt to clean the nest box in between broods in the spring or summer.

Some birds continue to nest after August; it’s not uncommon for birds to be nesting throughout September, so I wait until mid-October to clean my nest boxes.

It’s important to be sure that birds aren’t using the nest box before you take it down to clean it. Watch the box over a few days at different times of day to ensure there are no residents.

Many people like to clean their nest boxes in October (rather than later) so that birds can use them as roosts over the winter.

HOW SHOULD I CLEAN NEST BOXES?

Your nest box should have a removable panel to allow you to clean out the nest, often kept in place by a metal pin that you'll need to slide to the side. If it doesn’t, you’ll need to work out how to safely take it apart or modify the box to allow cleaning by adding your own removable panel.

Cleaning your box is easy. Remove the contents of the box and then dip the box into boiling water.

Wear gloves and wash your hands thoroughly afterwards, and be careful when pouring the boiling water from the kettle.

SHOULD I USE CLEANING FLUID?

You don’t need anything other than boiling water to clean your nest box. The purpose of cleaning the box is to prevent the nests building up to a level where the nest is very close to the entry, putting the chicks at risk of predation (you do this by removing the old nesting material) and to kill ectoparasites (you do this by pouring boiling water onto the box).

It doesn’t matter whether your box looks perfectly clean inside after you’re done. Birds don’t have clinical standards of interior design. There’s no need to install a ‘live, laugh, love’ sign.

THERE’S AN EGG OR A DEAD BIRD IN MY BOX

Don’t panic – it’s not unusual for some eggs to be unsuccessful or for one or more chicks to die. You’ll know this already if you’ve experienced the emotional rollercoaster of watching the nest cams on Springwatch. It doesn’t mean there’s anything wrong with your nest box.

When I cleaned out my blue tit nest box this October there was one chick in the box, and I laid her to rest in the nest below my willow tree.

WHAT NEXT?

Leave your nest box to dry out completely before replacing the removable panel or putting it back together.

Once it’s dry, put it back up so that birds can use it as a roost over the winter. You won’t need to touch it now until next Autumn!