Give a Brood a Home

National Nest Box Week is launched each year on St Valentine’s Day (February 14th) and is now an established part of the ornithological calendar. grownupgreen explores the role of UK households.

There are an estimated 5-6 million boxes in gardens the UK’ (BTO)

National Nest Box Week is organised by the British Trust for Ornithology (BTO), Britain’s leading bird research charity, whose work primarily involves studying the populations of our common and garden birds, and sponsored by Jacobi Jayne & Co, Britain’s nest box specialists.

The aim of National Nest Box Week is to encourage as many people as possible to put up nest boxes in order to help our breeding birds and other wildlife. The natural nest sites on which many of our bird species depend, such as holes in trees and buildings, are fast disappearing as gardens and woods are ‘tidied’ and old houses are repaired.

Since the event was launched in 1997, thousands of enthusiastic naturalists across the UK have put up boxes to compensate for this loss and it is estimated that there are now 5-6 million boxes in gardens the UK. So whether you’re a family with space for a box in your garden or a teacher, a member of a local wildlife group or a bird club member and could organise a work party, National Nest Box Week gives you the chance to give a brood a home.

The BTO have kindly agreed to share a selection of their Frequently Asked Questions about Nest Boxes with grownupgreen to assist households to participate in the event.

Which Box?

Question: There are so many different styles of nest boxes on offer these days made of various materials. What should I be looking for when buying?

BTO: Most people interested in putting up a nest box in their garden are hoping to attract Blue or Great Tits to nest, perhaps House Sparrow or even Robins and Spotted Flycatchers. Tits and sparrows prefer to nest in a box with a hole. A nest box should be well built and robust, made of wood, woodcrete (a mix of sawdust and concrete – as sold by Jacobi Jayne & Co.) or thick plastic. Avoid nest boxes built into bird feeding tables, as often sold at garden centres. Make sure that the entrance hole is at least 12cm from the floor of the box. The hole itself should be between 25-28mm for tits. Larger holes (32mm and more) will encourage other species such as House Sparrow or Tree Sparrow, though the latter species will use a 28mm entrance hole. To attract Robins and flycatchers to a nest box the design must be of an open-fronted variety.

Question: I have a large rural garden with many mature trees. I have heard that owls and Kestrels, which we get in our garden, will use nest boxes. I have looked in several large garden centres for such boxes but have yet to come across any. Please can you tell me where I can get hold of these, or alternatively, tell me where I can find details on how to build one myself?

BTO: Owls and Kestrels take readily to nest boxes if they are built and sited properly. Such boxes are not generally seen for sale in garden centres and hardware shops and can only be obtained from specialist suppliers such as Jacobi Jayne & Company.

Position?:

Question: I have received conflicting advice about the direction my nest box hole should face. Does it matter?

BTO: It does not really matter in which direction you position the entrance to your nest box. What is important is that you do not face the hole towards the prevailing wind as this will almost certainly mean that rain will get into the box during wet and windy weather. Try and avoid direct or prolonged exposure of sunlight on your box since overheating inside the box can sometimes result in heat stress to the nestlings.

Question: I have no walls or fences in my garden to fix a nest box to. However, I have several young trees and shrubs but they do not seem sturdy enough to tie or nail a box to. Can you suggest how I might get around this problem?

BTO: Nest boxes can be hung from trees and shrubs and are just as attractive to prospecting breeding birds as boxes nailed to fences or walls. The important point to bear in mind when hanging nest boxes from young trees and shrubs is to ensure that they are high enough from the ground to prevent predators such as cats from reaching them. A clear flight path to the entrance hole is also important to allow adult birds to see that there are no predators lurking nearby.

Question: I am an avid garden bird feeder and have many different types of seed and nut feeders all over my garden. Will putting up a nest box near to a feeder be alright?

BTO: Placing a nest box in close proximity to a feeding device or feeding station may well put off birds from nesting in the box. Remember that most nesting birds are highly territorial and do not like intruders in their territory. Either remove the feeders just before and during the breeding season or place the nest box well away from feeding stations.

Nesting Birds

Question: I have seen Great Tits going in to my nest box but am not entirely sure that they are nesting. Is it safe to lift the lid and take a look in the box?

BTO: Many species do not like to be disturbed at their nest site in the early part of the breeding season. However, one quick look in the nest box when you think they may have eggs will not do any harm. If you discover an adult bird sitting on the nest gently lower the lid and move quietly away from the box. Adult birds are much more tolerant to disturbance in the later stages of egg incubation and once they have young.

Question: I have discovered several dead nestlings in our nest box. I have removed them, which leaves four remaining live ones. Have we done something wrong such as position the box badly? Is there anything we can do to help the living nestlings?

BTO: This number of dead nestlings in a nest usually indicates that adults are having a hard time finding enough food for their chicks. As with many of the tit family, the hatching of their eggs coincides with the emergence of certain caterpillar types that adult tits feed to their young. Anything that may disrupt the hatching of the caterpillars, such as cold and wet weather, will result in a shortage of food for the tits. This is quite a natural phenomenon and happens from time to time. In very bad years the whole brood may perish through starvation, though it is more normal for the brood number to be regulated by the amount of food that is available in the wild. Unfortunately, there is little one can do to help when this sort of thing happens.

Nest Box Maintenance

Question: Should I clean out the old nest from my nest box or will the birds use the same nest again next year?

BTO: You should remove old nests from your nest boxes. The best time of year to do this is pretty soon after the breeding season and before the onset of winter. The Wildlife & Countryside Act 1981 permits the cleaning out of nests containing abandoned eggs between 1 August and 31 January. The eggs must be destroyed promptly and cannot be kept or sold. Nests often harbour fleas and an old nest left in a box over winter provides a warm home. If, however, you do forget to remove an old nest make sure you clear it out before the end of January. Put old nests into a polythene bag and seal it straight away. This will keep the fleas contained in the bag rather than jumping all over you! Wear protective gloves or wash your hands when you have finished. If the old nest is badly infested with fleas you can give the nest box a quick squirt of natural pyrethrum to kill off fleas and any other parasites that might be lurking there.

For specific information about this year’s National Nest Box Week, visit the website www.bto.org/notices/nnbw2005.htm There are a number of other Questions and Answers on the BTO website* www.bto.org

The BTO has adopted the special ‘woodcrete’ nest box of Jacobi Jayne & Company. Their website is www.jacobijayne.com

It can also be great fun to make your own nestboxes and the BTO has produced a nestbox guide that can be purchased by telephoning the BTO on 01842-750050 or by emailing info@bto.org

If you are interested in how looking after garden wildlife can help environmental sustainability go to our Library to search for articles on ‘birds’, ‘wildlife gardening’ and ‘trees’.

BTO & grownupgreen - 07/02/05

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