102 BRITISH BIRDS. [vou XI. 
Of the genus Acrocephalus I have not often seen individuals 
stopping on the way in spring, but once I found a Great 
Reed-Warbler (A. arundinaceus) singing in a hedge in dry 
country; I have not heard A. scirpaceus or A. “aquatious 
sing in autumn. 
Whitethroats (Sylvia communis) stop in large numbers 
near the coast on the spring migration, but (apart from a 
few remaining to nest) sing rather “little ; the Garden-Warbler 
(Sylvia borin) is the only other member of the genus met 
with regularly, and I have not heard it sing at either season. 
The Rock-Thrush (Monticola savatilis) is frequently seen 
near the coast in spring, but seems not to sing. 
The Wheatear (Hnanthe cnanthe), Whinchat (Savxicola 
rubetra) and Redstart (Phenicurus phenicurus) are all 
abundant in spring, but I have never heard any of them 
sing, and they are generally quite silent: the same may 
be said of 2. hispanica. In autumn Redstarts are often 
noisy. 
Nightingales (Luscinia megarhyncha) of course breed in 
the neighbourhood; but during the spring migration I 
have often heard them singing in the coast macchia in places 
where none remain to nest. On the other hand, late Robins 
(Erithacus rubecula), stopping on passage after the winter 
residents have left, seem usually to be silent. 
I have heard Sand-Martins (Riparia riparid) singing in 
numbers near the Tiber mouth on their spring passage. 
The flocks of Swifts (Apus apus) which stop to feed during 
the autumn migration, after the local birds have gone, seem 
always to be silent; but once in spring I heard screaming " 
from a flock which, from their behaviour, appeared to be 
passers. The Alpine Swifts (A. melba), which stop near Albano 
in the autumn, are also silent. 
Cuckoos (Cuculus canorus) seem to call only oceasionally.. 
[ have a note of ten met with on the Isola Sacra on April 12th, 
1914, of which three were red and one brown: two sang 
in a hoarse voice. On the following day seven seen (one 
red). two or three of which sang. On May 3rd, four grey 
and three red seen and one other heard. | cannot be sure 
whether I heard a red one call. 
It is evident that the Warblers (particularly of the genus 
Phyiloscopus) are much more inclined to sing on migration 
than the Chats or Flycatchers. With this question, as 
with that of singing in winter quarters, the tendencies of 
certain groups seem to play more part than distance from 
breeding-grounds, 
