21 APRIL 1939, Page 18

Nesting Holes

There is a new nesting-box that a pair of blue tits visit continually, though they have not yet begun to build. They go in and out of the box, but spend most of their visiting time in pecking round the hole. The hole is of regulation size—that is, of the size of a halfpenny—and the tits can enter easily. Their pecking has the very smallest effect, for the box is made of larch and the walls are thick. The object of their activity is not altogether clear. Do they object to the sharp edge of the newly-cut hole, or do they, like wasps, like the nesting-hole to be given signs of the nesters' own work? Sparrows, whose beaks are much less powerful than the tits', will on occasion enlarge the hole of an old half-rotten nesting-box, but the tits ought to desire as small a hole as will accommodate their little bodies. In the same garden some years ago the tits had a prolonged duel with a wryneck for an old nesting-box, and finally the tits won, to the grief of the observers, for it is a comparatively rare feat to attract a wryneck to the garden, and much rarer to lure it into a nesting-box.