40 DB. E0KSTER ON THE RETURN OF SWALLOWS. 



On the Irregularity in the Eeturn of Swallows and other vernal 



migratory Birds, this Season, 1857. By Dr. Thomas Forster, 



F.L.S. &c. 



[Read June 2, 1857.] 



As the following facts will prohahly be interesting to the Linnean 

 Society, I have carefully extracted them from my Journal of 

 Natural History. 



The order of arrival of the Swallow tribe has been quite re- 

 versed. The Chimney Swallow, Hirundo rustica, who usually 

 arrives in Belgium about the 15th of April, made his first appear- 

 ance early in May, and then only a straggler or two. This species 

 is not yet common, and after a most careful search after Swallows, 

 up to May the 11th, I had not myself seen a single specimen : 

 one or two are said to have been observed about the waters of 

 Ixelles. 



A straggling Martin, H. tirbica, was observed by me on the 

 23rd of April ; but I did not see another till the 9th of May, and 

 this species is still very scarce. Today (14th of May) a few 

 Swallows may also be seen. In general, both species are by this 

 time very numerous. 



The Swift, H. apus, who usually arrives in Belgium before the 

 1st of May, did not appear till the 9th ; and yesterday these birds 

 are become common, though much less numerous than last year. 



The Sand Martin, H. riparia, has not yet arrived. 



The Cuckoo has been heard only once or twice, and that in the 

 first week of May. 



I find by consulting ancient records that the occasional delay of 

 the arrival of the Swallow was noticed in Greece of old, and it is 

 probably to some occasion of this kind that we may attribute the 

 line in some poet, I believe Aristophanes, 



£2 Zeu, ye\i%tt)v dpa irure (pan'^trerai ; ! ! ! 

 The absence of west winds on the continent has been no less 

 remarkable, as this wind has always been connected with the 

 return of the Swallow — 



" Cum Zephyris, si concedes, efc hirundine prima." 

 So says Horace ; and the Martin has also been said to come with 

 S.W. breezes. Ovid represents this wind as blowing 

 " Quum luteuin celsa sub trabe fingit opus." 

 The scarcity of all the vernal songsters has likewise been re- 

 marked : the season is altogether late and anomalous. 

 Bruxelles, May 14th, 1857. 



