I spotted this rook with a very unusual beak in Galway city lately. Despite the unusual shape it seemed very healthy and was well able to pick up food off the street. Is it a genetic fault or the result of some infection? – Neil Spellacy, Galway
Niall Hatch of BirdWatch Ireland suggest that there are several reasons for such anomalies, including a genetic defect, a viral infection and injury resulting in misaligned bill-tips. The outer sheaths of birds’ beaks grow continually throughout their lives, but when they are properly aligned, the tips wear each other away and the beak stays straight and normal in length. Such bill misalignment can happen to pretty much any bird species, but it is much more commonly reported in rooks and other crow species because their intelligence, resourcefulness, adaptability and social bonds allow them to overcome their disability and to survive in spite of it.

I came across this strange substance about the size of a human ear while clearing a flower bed of moss and dead matter. I’d like to know what it is, and also how to best deal with it if I find more of it? – Maria Meany, Douglas, Cork
This is a species of Nostoc, commonly called Witch’s Jelly due to its slimy, blobby, jelly-like appearance. Nostoc belongs to the cyanobacteria – a very ancient group of organisms which are capable of fixing atmospheric nitrogen into the soil, so deal with it by leaving it there to enrich the soil.

I photographed this bird feeding in my garden in suburban Cork. I assume it a parakeet – the same bird I have seen in Hyde Park, London. Is it a threat to our native birds (and vegetation)? – Pádraigín Riggs, Cork
Yes, this is the rose-ringed parakeet which is native to parts of southern Asia and central Africa. It was first recorded here in 1998. They are traditionally kept as pets, and the most likely source of introduction into Ireland is through birds escaping from confinement or being released into the wild. The verified recording of juveniles with adults in one Dublin city location indicates the possibility of a breeding population here, as it is less likely they are escaped juveniles. In cities like London, Amsterdam and Brussels, the population of these birds is now out of control, and they cause economic damage and problems for native species. There have been calls to introduce measures to prevent parrots from invading new areas in order to limit future harm.

Can you identify these little fibrous tubes? There were quite a few of them attached to various pieces of timber I had stacked in a shed. I did see a yellow caterpillar nearby so it may be associated with them. – Laurence Mc Giveren, Raheny, Dublin
Dave Allen of mothsireland.com (who welcome all such records) has identified them as the overwintering cocoons of the bee moth (Aphomia sociella) – one of the larger micromoths. Their larvae parasitise bumblebees and wasps whose nests they infest with silken tunnels. They feed on the nest materials, the honeycomb and finally the bee or wasp larvae there.

I go for walks in Brittas Bay most days and have come across these snail shells. Please can you explain this? They are in a few places but all in sand dune walkways. – Bernard Wojnar
The stone in the centre of the shells is called a “thrushes’ anvil”. Snails are common in sand dunes and thrushes gather them and bang them off the much rarer occurring stones to break them before devouring the contents. Because of their unique ability to do this, snails can form an important element of the thrushes’ diet.
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