5118 THE ZooLoGist—OcrToBER, 1876. 
garden warbler utters a low, guttural note, especially when—in the wane of 
summer—it is searching among the bean-sticks for insects or discussing a 
fat larva of the common cabbage butterfly; and I am not sure that—with 
its near relative, the whitethroat—it does not give vent to the same sort of 
murmur when searching amongst the gooseberry and currant bushes, or 
amongst the fallen fruit beneath them. I could never satisfy. myself whether 
one or both species produced the sound, but in any case it seems to have 
been an inward note of satisfaction and complacency, rather than one of 
fear or alarm. This “murmuring” will doubtless be understood as in no 
way connected with the song of the birds. I should like to know whether 
any other of the warblers are in the habit of producing this sound, and 
whether it is a well-known trait in the three I have named. The scanty 
ornithological literature to which I have access is silent on the subject.— 
G. B. Corbin; Ringwood, Hants. 
Erratum.—In my note on the song thrush (S. 8. 5003), for’ singing 
music vead ringing music.—G. B. C. 
Distinguishing Characters of the Aquatic and Sedge Warblers.—Last 
October I saw an undoubted aquatic warbler at Cliffe, in Kent, which 
I duly recorded in the ‘ Zoologist’ (S. 8. 4693). Though I confess that in 
commencing the study of Ornithology I have made several rather serious 
mistakes of identification, I think there is no reasonable doubt here. Iam 
surprised to have heard it said that the aquatic warbler and the sedge 
warbler are very like each other and difficult to distinguish. Undoubtedly 
there is a certain similarity in the distribution of the markings: each 
species has a whitish eye-streak surmounted by a dark band, and each 
species has the ground colour of the upper plumage more or less marked 
with dark striations. ‘There the resemblance ends, and we may first note 
a radical difference in the colouring of the crown of the head, that part 
being very light-coloured in the aquatic warbler, but in the sedge warbler 
olive-brown with darker markings. But it is very misleading to speak, as 
so many do, as if this were the only great difference between the two birds. 
I have referred to a similarity between the styles of marking, but at how 
great a distance can this be detected? Seen with the naked eye at a very 
little distance the sedge warbler seems to be of a uniform olive on the upper 
surface, barring the tawny rump, the dark striations being far too faint to 
be visible. Even the tawny red of the rump blends so harmoniously with 
the olive of the back that it wants a young pair of eyes to detect the 
difference. An excellent ornithologist said to me one day in Lincolnshire, 
“ What are those birds that look to me like willow wrens? Your eyes are 
younger than mine.” The birds were sedge warblers, and I have elsewhere 
noticed the same superficial likeness between this bird and the willow wren 
group. But when we look at the aquatic warbler we find a broad and 
distinct blackish band on each side of the head, and the dark markings of 
