At about what date in spring should we stop feeding peanuts and fat-based seed cake to wild birds? Christine Walker, Ballygar, Roscommon
We stop feeding the birds as the spring supply of insects builds up. There is some concern that if tits feed their young with nut- fragments, the nestlings can't digest them, but that sounds too stupid for nature to allow. Bird-table nuts and seeds help to launch many garden species into the nesting season in good condition - but wrens (see next letter) seem to manage quite well without us.
Since Christmas, four wrens have been sleep- ing nightly in a housemartin nest outside my bedroom. I feel very honoured and wondered was it common for them to roost together in winter. I put out nuts and seeds which caused a lot of activity among the other birds, but the wrens fly out of the nest at first light and return at dark again.
Pol Brennan, Thomastown, Co Kilkenny
Wrens roost in nests, their own and others, in a communal ball in winter for the shared heat. They are strict carnivores and are not interested in nuts or seeds, depending entirely on insects, spiders and cocoons for food.
I swept my chimney recently and put the collected soot on my compost. Within two minutes, about 20 crows had swooped on the compost heap. What was the attraction?
Noel MacCanna, Blessington, Co Wicklow
These were probably jackdaws who like to build their nests in chimneys and so are familiar with soot. They could use it to get rid of parasites in their feathers, or it may have another attraction for them - perhaps they need carbon for some intestinal reason, or use the clinker in it for their gizzards.
Edited by Michael Viney, who welcomes observations sent to him at Thallabawn, Carrowniskey PO, Westport, Co Mayo. Email: viney@anu.ie