April, 19 1 2. The Irish Naturalist, 65 



THE AUTUMN MIGRATION OF SWALLOWS AT 



ROSSLARE HARBOUR. 



BY ALFRED D. DELAP, M.INST.C.E. 

 [Plate 2.] 



RossLARE Harbour is on the east coast of Co. Wexford, 

 6 miles north of Carnsore Point, the extreme south-eastern 

 corner of Ireland. A glance at the map (Plate 2) will show 

 that the coast -line here runs nearly east and west. Tuskar 

 Rock and hghthouse lie 6J miles south-east of the harbour. 

 The mountain of Forth is a low ridge extending from the 

 town of Wexford about 5 miles in a south-by-westerly direc- 

 tion. The point where the following observations were 

 made, except when otherwise stated, was the top of the 

 clay bank or cliff immediately^ opposite and south of 

 Rosslare Harbour. 



For the past ten years the writer has noticed, during the 

 autumn, large numbers of Swallows passing along the 

 coast in a westerly or north-westerly direction, and at first 

 it was thought that these were birds that had bred further 

 west, that they had travelled along the south coast 

 and were still following the coast -line to reach some point of 

 departure from Ireland, possibly a little to the north of 

 this, and that it was only the accident of the coast -line 

 trending nearly due west that determined the unusual and 

 unexpected direction of their flight at this point. This 

 idea was rather strengthened by noticing that numbers of 

 birds, especially in calm or fine weather, instead of closely 

 following the coast -line, turned north as if to take a short 

 cut across Wexford Bay and pick up the coast some miles 

 further on. 



This flight of birds is usuall}^ in the form of a thin stream, 

 often lasting for several hours without a break, with seldom 

 more than a dozen birds in sight at any time ; they are 

 travelling low and moderately fast, taking advantage on 

 windv davs of the shelter of the low cliffs alonsj the coast. 

 Occasionally parties will stop and feed in some sheltered 



