Private nature reserve in Shropshire

We have been trialling nest boxes at this private nature reserve in Shropshire since 1997. The main habitats present are improved grassland grazed by sheep, new growth mixed woodland (planted in 1996) and a 5 hectares (12 acres) of mature woodland which occupies a damp valley. The wood is dominated by alder (Alnus glutinosa).

A variety of different nest box designs and materials are used, including sawn timber, plywood and cement/woodfibre mixes. To increase the chances of the boxes being used and for ease of comparison, all of the hole boxes use a 32mm entrance. The boxes are sited at a variety of different heights, aspects and locations within the site. We have also been experimenting with nest boxes sited on readily available tree or fencing stakes, to allow for gardens with no suitable places to mount a nest box. These boxes are, of necessity, fairly close to the ground (1.5m or lower) but the success rate of the boxes compares well with more conventional siting.

Most of the nest boxes are occupied by Blue Tits (Parus caeruleus) and Great Tits (Parus major), although Nuthatches (Sitta europaea) and Coal Tits (Parus ater) are recorded in some years. In 2005 a Pied Flycatcher (Ficedula hypoleuca) nested, which was a first for the site, although males had been recorded singing on two previous occasions.

Robins (Erithacus rubecula), and Blackbirds (Turdus merula) are regular users of open nest boxes, with one very old box being a particular favourite with the Blackbirds. These boxes are a bit of a squeeze for such large birds, which is why we decided to produce the specialist Blackbird Nest Box.

We have also been experimenting with nest boxes to help Marsh Tits (Parus palustris) and Willow Tits (Parus montanus). The design shown is one that has been developed by the British Trust for Ornithology (BTO) and aims to reproduce the sort of rotting timber that these birds naturally nest in. The best way we have found of achieving this is to fill the inside of the box with chunks of wood that are so rotten that they have become soft to the touch. The photo shows how the birds have made a nesting chamber in the remains of a piece of rotting alder. This nest box has successfully fledged five young Marsh Tits in three of the last four years. In the year that we forgot to add rotting wood the nest box was occupied by Blue Tits, who may well out-compete Marsh Tits for more conventional nest box designs.

Some of the images also shows signs of damage by grey squirrels (Sciurus carolinensis). Sadly this is very common in many woods in England and Wales. In some areas nest box workers have to fit metal plates to entrance holes or, better still, use nest boxes made of a cement/woodfibre mix