BIRDS OF THE UNITED STATES. 
173 
But it is its final actions that impress the beholder with wonder and 
admiration. The hitherto trailing wings now assume a condition of rigidity, 
and commence a firm, but slow, downward and forward movement, Avhich 
steadily increases in power and rapidity, until the swiftly-vibrating wings 
appear only as a semi-circular outline of mist above the bird, thus giving- 
rise to a sound which may be a}:)pro23riately likened to the reverberations 
of distant, muttering thunder. These sounds are -most generally heard 
during the cool hours of the morning, when the spirits are buoyant after 
a night of refreshing slumber. But as the day advances, they are less 
frequent, and irregular. So nicely can they be imitated, that many a bird 
is drawn to his doom, when advancing to meet a supposed antagonist. 
As the drumming of the Buffed Grouse is as often heard in fall as 
in spring, it has long been a mooted question as to its significancy as the 
call-note of the male during the breeding-period. But there cannot be the 
least doubt of the correctness of this interpretation, for we have the most 
incontestable proof of it in the responsive actions of the female. Nuttall 
is jDrobably correct in ascribing the autumnal exhibition of the same won- 
derful power to self-gratification, and in affirming it to be, in many 
instances, “an instinctive expression of hilarity and vigor.” 
Besides the 23eculiar drumming sound which the males produce during 
the love-season, they give ex 2 )ression to vocal utterances which are no less 
remarkable. These are generally given forth when about to arise from 
the ground, and consist of two well-defined and characteristic notes. The 
first may be described as a sort of cackle, repeated several times in lively 
succession. The other, which closely follows in its wake, is a peculiar 
lisping whistle, which has not inaj^tly been comjjared to the cry of a 
yonng bird. These notes doubtless play a j^art in the reconcilement and 
bringing together of the sexes after their temporary sejjaration. 
While the courting-season continues, it is not an uncommon occurrence 
to find a single male in the midst of several females, before whom he is 
engaged in showing off his many good qualities and graces. In such a 
