All our lovely swallows departed on September 18th. Coincidentally, Ireland and Western Europe began to experience an unexpected period of very good weather. Do you think the swallows anticipated this fine spell to take flight for their journey to Africa? Azariah Shortt, Inishowen, Co Donegal.
Migrant birds like the swallow are certainly likely to respond to good local conditions, such as clear skies and rising pressure soon after the passing of a cold front, but this gives them no guarantee of good weather all the way. The sudden departure of all the swallows in the neighbourhood can be very striking. The main autumn passage of swallows from Ireland peaks in August and September, but a trickle may continue through October into November. There are sometimes huge movements: in one record, on the Wicklow coast, more than 50,000 swallows flew south over Broad Lough in six hours on October 2nd, 1982.
Edited by Michael Viney, who welcomes observations sent to him at Thallabawn, Carrowniskey PO, Westport, Co Mayo. e-mail: viney@anu.ie. Observations sent by e-mail should be accompanied by postal address as location is sometimes important to identification or behaviour.