586 FURTHER NOTES ON 
fifth, quite a young one, which was, for the time being, 
silent. This fact of there being five of these birds within 
such a very small area is certainly a very rare occurrence. 
On the whole the Hybrid game is increasing, for I know 
of two cocks that have drummed in the district of Jung- 
Bunzlau, of two others in the south of Bohemia, and of one 
in the neighbourhood of Gmunden at the foot of the Alps, 
on ground where two old Blackcocks, unattended by Grey- 
hens, have now been going about among a very large stock 
of Capercaillies for a considerable time—a fact that may lead 
to interesting results. In order to account for the increase 
of the Hybrid Grouse, and by so doing for the cause and 
manner of its origin, more materials ought soon to be col- 
lected, and at least a certain amount of light be brought to 
bear on this highly interesting zoological question. 
To return, however, to our own special experiences. From 
Svijan-Podol we drove to the ground, which was not far off, 
and pulling up on the road I posted myself near the place 
where two cocks had settled the previous evening, while my 
brother-in-law went a little further on to two others. 
All the four birds began calling about the same time, com- 
mencing with a peculiar prolonged Woodpecker-like whistle 
which I had never heard before, for in 1880 I had found 
the cock in the height of its drumming when I approached 
its perch. This whistle was followed by the singular song of 
the Hybrid Grouse, which never varies, and is quite charac- 
teristic of the bird, and the bars of which (“ Verse”) follow each 
other much quicker than they do in the case of the Caper- 
eaillie, there being no intervals, while the pitch is always the 
same, and much higher than in the songs of our two other 
Wood-Grouse. 
The clear “Schliige” take the place of the so-called 
“ Ziihlen,” and a most remarkable croaking noise is substi- 
tuted for the principal note (““Hauptschlag”’) of the Capercaillie. 
