For many garden birds the ability to survive and increase in numbers is not limited by food supply but by a lack of suitable nest sites. This is especially true when the old, dying and rotten trees, which contain most nest holes, are cut down and removed.

Many of these bird species, as well as bats, are of benefit to us because they eat insects which are pests in the garden.

A suitably sited nest box may help in a very direct way, for example, a single pair of nesting great tits will eat more than 10,000 insects and in apple orchards reduce pest damage by 25%.

Blue tits and great tits prefer boxes with round entrance holes (25mm and 28mm in diameter respectively - left).

Robins, flycatchers and wagtails prefer open-fronted boxes (right)

Materials for the bird boxes were purchased through a generous donation from the Tolka Branch of Birdwatch Ireland, who meet in the Botanic Gardens on a regular basis.