In mid-December we counted 18 little birds entering the blue tits' nesting box at the edge of dark. It transpired that they were wrens, and we wondered how they all fitted. During the cold spell at the beginning of February, I did another count and was even more surprised to see 30 flying in. How did so many discover this roost under the overhang of our veranda, and how do so many fit in an ordinary titbox?
Olive McCormick, Gorey, Co Wexford
Wrens are so small that they need the warmth of each other to survive in cold weather. It is strange that they should gather in a nest box or other small enclosed space in winter and roost together in a tight ball, because they are not flocking birds; but it is their common practice. Wrens are very numerous in suitable habitats, and there can be anything up to 30 or more breeding pairs in a square kilometre. They also take turns moving from the centre of the ball to the outside during the night.
We have always had an enormous number of magpies around our place. Thank goodness they seem to have gone, and instead we have a resident pair of jays. Could this have anything to do with the disappearance of the magpies?
Evie Anderson, Kilternan, Co Dublin
One thing is certain: if the magpies were still in residence they would have driven out the jays. Whatever the reason for the disappearance of the magpies, they left free a territory suitable for the jays, who like a woodland where there are oak trees.
Although the pale tussock moth is of local distribution in the southern half of the country, we have seen it a few times on our farm (Eye 4/11/95). The adult stage of this moth normally appears in May or June and the caterpillar in late summer or autumn. It overwinters as a pupa. On January 29th we found a newly hatched adult on the inside of our sitting room window. The caterpillar must have come into the house and the pupa hatched early in the warm room.
Jim Fox, Coursetown, Athy, Co Kildare
