New nesting boxes for birds

Thanks to the generosity of the Redland and Cotham Amenities Society (RCAS), RGCG has been able to purchase sixteen nesting boxes for birds.

We have chosen four different types of box, in two different colours (brown and green). The different boxes are suitable for different species of bird. Open-fronted boxes are suitable for wrens and robins (if well hidden), pied and grey wagtails, and song thrushes and blackbirds. Boxes with 32mm oval holes (right box) are used by house and tree sparrows, nuthatch, great tits and redstart. Boxes with 32mm round holes are used by great tits, pied flycatchers and house and tree sparrows. Boxes with round holes of 28mm diameter (left box) are used by blue tits, coal tits, great tits and tree sparrows.

We put up the first nine of these on trees at the north end of the Green on a very gloomy - but thankfully dry Saturday towards the end of January.

A blue tit was inspecting the first box we put up within minutes of us removing the ladder from the tree!

The first photo shows the new box in the rear, and in the foreground is an old wooden box, whose hole has been enlarged by a great spotted woodpecker in search of chicks to predate.

A further seven boxes went up in the two following weeks, in and around the Dell area, and near to the tennis courts and children's playground.

Notes about our bird boxes

The boxes are made of a product called "Woodcrete" which is a mix of wood fibres and concrete. These boxes have many advantages over wooden nest boxes. First, they provide greater protection against nest predators such as grey squirrels and woodpeckers. As we have great spotted and green woodpeckers in the Green and adjacent allotments, and a population of grey squirrels, protection is a very important consideration. The boxes are extremely durable and resistant to all weather conditions, and so will last many years. Additionally, the mix of wood and concrete helps to stablise the internal temperature of the box, resulting in significantly less fluctation of temperature from day to night, This is important not only during the breeding season, but at other times of year, when birds may use boxes to roost. Additionally, the insulating properties of the box allows birds to nest a bit earlier in the year, which has the benefit of enabling them to take advantage of natural food supplies, and potentially also enabling them to have an extra brood later in the year.

When attaching to trees, bird boxes can be put at heights varying between 1.5m and 5.5m (5 - 18 feet), depending on a variety of factors. These include the type of bird it is hoped to attract, and whether there are many cats in the area: if so, locating the box even higher is advisable. Boxes are generally located with the open/hole side facing between north and south east, to avoid both prevailing winds and strong sunlight. In woodlands though, the best side is the dry side of the tree trunk. Open-fronted boxes also benefit from being hidden among climbing plants such as ivy for best protection from predators. Another consideration is the proximity of nearby vegetation, as these give young birds taking their first flights more help and protection. Spacing is another important factor: boxes catering for the same species generally should be spaced no closer than 10 metres to each other, as birds are territorial.