We have lots of sparrows coming to our bird table, and recently my husband spotted one with a white head. Will this bird be ostracised or be able to breed like the others? – Ann Mangan, Dungarvan, Co Waterford
Sometimes a leucistic bird is driven away, but yours seems to be part of the flock. It will be able to mate, and the genetic mutation may be passed on to progeny.
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I saw this most beautiful little leucistic chaffinch in my garden that was fascinating to watch. How common are they? – Lelia McHale, Knockmore, Co Mayo
Leucistic chaffinch are not common but are indeed beautiful. Leucism is a genetic mutation that prevents melanin (which gives colour) from being deposited normally on feathers, but it is present in other parts of the body.

This beautiful winter visitor, a great egret, is wintering in Baltimore. It seems happy with a flotilla of ducks and a watchful heron. – Richard Marten, Baltimore, Co Cork
The great white egret is regular visitor to the south coast in late spring and summer, but occasionally it now overwinters here.
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This fungus appears sometimes in the garden. In the soil it has thin, white roots that stick to wood. What is it and is it poisonous? – Richard Knatchbull, Bray, Co Wicklow
It's red cage fungus, related to the stinkhorn family. I would not recommend eating it.
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We found these growing on the verge opposite our house. They are proper, picture-book toadstools. – Ed Armitage, Douglas, Co Cork
Fly agaric, Amanita muscaria, is a well-known poisonous mushroom. It is associated usually with birch, spruce and oak trees.
Sometimes on bright mornings, butterflies come alive and fly around my house. Should I leave them in the house or put them out? Will they survive outside in the winter? – Sheelagh Coyle, Mountmellick, Co Laois
Don't put them out unless you put them in a shelter such as a shed.
Ethna Viney welcomes observations and photographs at Thallabawn, Louisburgh, Co Mayo, F28 F978, or by email at viney@anu.ie. Include a postal address