NOTES ON THE MIGRATIONS OF THE YELLOW WAGTAIL. 79 
I should like to ask Mr. Cordeaux if he has observed any of those 
fine variations in the colour of individuals forming these flocks, 
analogous to those he has detected in the Starling and other species. 
Comparing a male JZ. flava from South Russia, with local examples 
of M. raii,1 find the latter, brilliant as they are, are surpassed in 
richness of tint by the former, and I should expect to find eastern 
examples of the latter to be brighter in like manner than are our 
British-bred birds. 
I should also like to remark that Mr. Cordeaux’s explanation 
of the fact that JZ fava does not turn up amongst these flocks 
of M. razz is not altogether sufficient. He attributes their absence 
to the different periods of migration of the two species, the former 
being described as later in arrival at its breeding-grounds by a month 
and ‘also earlier in its departure than the latter. This is perhaps 
true of Central and Southern Europe, but on referring to Heligoland 
data (‘Naturalist,’ 1887, p. 313, et seq.), I find evidence there that 
M. flava is on the move over the whole time occupied by the migrations 
of M. raii. I extract the following notes :— 
Spring—April 3—JZ flava. Some. 
” ” 5M. fi 
“a » 18—MM. flava. Some. 
” 19—MV/. flava. Many, etc., etc. 
The return movement was first observed August 25th, lasting in 
more or less strength till October 6th. 
Referring to the Humber and Severn route as a fly-line (which 
I am fully aware is principally used by zénfer migrants, except 
locally), though relatively of small moment, and perhaps of more 
interest as suggesting an ancient movement along what was once 
a sea coast, I think Mr. Cordeaux rather under-rates its importance. 
During a residence of seventeen years in the Trent valley, I have 
Seen at various times a great deal of migration, but I have no 
hesitation in stating that what I have observed is only a small 
fraction of that which annually takes place. Many of my notes are 
the result of happy accidents, birds passing so much in the night, 
and. consequently escaping notice unless something in the nature of 
a thunderstorm, street lights, or even a number of clocks striking the 
hour alarms them and causes them to cry out. Only a short time 
numbers comprising these flocks, I can say that their voices were 
most plainly to be heard above the rushing of the rain and general 
disturbance. 
March 1894. 
