Some years ago there was, as far as I remember, a major security alert at Mountjoy prison in Dublin when a swan dropped out of the sky and landed in the exercise yard.
The swan, probably the only animal in the area, was eventually rescued by a well-known person.
That man, Mr Richard Collins, is Ireland's foremost expert on swans, especially the most common of Irish swans, the mute.
Richard is a "swan doctor". He knows more about the birds than virtually anyone else in Europe because his academic achievements were built on a seven-year study of mute swans.
Richard, who lives in Malahide, Co Dublin, told me that mute swans lack grey matter, so much so that they cannot distinguish between a white plastic bag and one of their own.
The Mountjoy swan was flying along the canal on Dublin's north side, saw the plastic bag left by builders in the exercise yard and decided to swoop down for a chat.
Landing is no problem for swans. They can manage on quite a short runway.
The real problem is when they want to take off again since they are the jumbo jets of Irish ornithological airspace.
And so it was that Richard Collins found himself in prison to rescue a rather large, stupid swan which he discovered was one of the many birds he had tagged during his research project.
The reason I mention Richard is that he is one of the main hosts for the ESB Lough Ree Environmental Summer School from Friday, December 3rd, to Sunday, December 5th, in Lanesboro, Co Longford.
Richard will be joined by the environmentalists Ms Cathryn Hannon and Mr Dick Warner, of television fame, who will host a series of field trips over the weekend for the interested.
The idea behind the weekend is to highlight Lough Ree and the Shannon basin as a precious resource for the people of this country.
This is the second winter school run by the Lough Ree Development Association.
For information on the winter school, contact the association at (043) 27070.