Bygone birding: Why 10 housemartins were attracted to funnel of naval vessel en route from Rosyth to Belfast

                                                   

Extract from the  1951 edition of The Sea Swallow - fourth annual report of the Royal Naval Bird Watching Society.

Describing birds seen during a coastal passage from Rosyth to Belfast during May, 1951, a society member writes:

"About noon we proceeded North from May Island, and were joined in the afternoon by 10 Housemartins which flew up repeatedly to the funnel and superstructure, twittering, and using these as if they were flying up under the eaves of a house. 

"It occurred to me that they were 'sipping' droplets of condensed steam escaping from the syren.

"When a large drip tray of fresh water was placed handy on deck, the martins were soon perching on its edge. 

"They roosted for the night on the tubular guide for the syren wires on the lee side of the funnel, and eight of them were there the following morning at 4 am when the ship ran into dense fog. 

"The sounding of the syren about 10 feet from where they were roosting made no impression on them, and, indeed, they often flew right up to the syren when it was in full blast. 

"They flew about the ship all morning and disappeared only after the ship had anchored five miles off shore in the Moray Firth."