If the cuckoo calls from a tree without leaves, sell your cow and buy corn.
Note: The cuckoo bird is giving a warning. A warning that the season to come, like the tree on which it is perched, will be barren. Therefore, a wise person will sell the clan’s riches, which ancient Gaels measured in cows, and buy food. In the north, there is another version of this proverb, “An tráth a ghaireann an chuach ar an sceach lom, díol do bhó agus ceannaigh arbhar.” (When the cuckoo cries on the bare thorn bush, sell your cow and buy corn.)
Ancient Celts were well known for their powers of augury, the ability to foretell the future from the behavior of animals. Some Celtic diviners specialized in bird augury. Diodorus Siculus, an ancient Roman writer, told of Druids who predicted the future from the flight of birds. “An Irish version of the Historia Brittonum, by the Welsh historian Nennius, includes an ancient poem which refers to six Druids who lived at Breagh-magh and who practiced the ‘the watching of birds’.” (Peter Berresford Ellis, The Druids, William P.Eerdsmans Publishing Company, 1994, p. 223.)
Part of this tradition of ‘the watching of birds’ survives in Irish proverbs. Pádraig Ua Maoileoin, who was called an Seabhac (the Hawk), devotes a whole chapter of Seanfhocail na Mumhan to proverbs about birds. He gives proverb # 2259 “An gobadán (nó gobachán) i mbeale cuaiche.” (The sandpiper (or sharp-tongued person) is in the mouth of a cuckoo.) Here, the Hawk is pointing out that in Irish, the words for sandpiper and sharp-tongued person are synonymous. This is a natural artifact of a belief that the behavior of birds influences the lives of people. In other words, Druid gossips (one type of sharp-tongued people) should be good to sandpipers and listen to cuckoos.