l above the normal level of life. The act of singing is a
pleasurable one, an expression of superabundant energy and joyous
excitement. Thus love-songs, serving first probably as a call of
recognition from the male to the female, came to be used as a means
of seduction. Every one is familiar with the exquisite lyrical
tournaments of our nightingales; their songs during the love season do
not cease by day or by night, so that one wonders when sleep can be
taken; but as soon as the young are hatched the music ceases, and
harsh croaks are the only sound left.[70] The song of the skylark,
with its splendid note of freedom, is more melodious and more frequent
in the season of love's delirium.[71] Another bird, the male of the
weaver bird, builds an abode of pleasure for himself, wherein he
retires to sing to his mate.[72] A very beautiful case of the use of
these love-calls by the tyrant bird (_Pitangus Bolivianus_) is
recorded by W.H. Hudson.[73]

"Though the male and female are greatly attached they do not go
afield to hunt in company, but separate to meet at intervals
during the day. One of the couple (say the female) returns to
the trees where they are accustomed to meet, and after a time
becoming impatient or anxious at the delay of her consort,
utters a very long, clear call-note. He is perhaps a quarter of
a mile away, watching for a frog beside a pool, or beating over
a thistle bed, but he hears the note and presently responds with
one of equal power. Then, perhaps, for half-an-hour, at
intervals of half-a-minute, the birds answer each other, though
the powerful call of the one must interfere with his hunting. At
length he returns: then the two birds, perched close together,
with their yellow bosoms almost touching, crests elevated, and
beating the branch with their wings scream their loudest notes
in concert--a confused, jubilant noise that rings through the
whole plantation. Their joy at meeting is patent, and their
action corresponds to the warm embrace of a loving human
couple."

Some birds, who are ill-endowed from a musical point of view, have
their wing feathers or tails peculiarly developed and stiffened, and
are able to produce with them a strange snapping or cracking sound.
Thus several species of snipe make drumming or "bleating"
noises--something like the bleat of a goat--with their narrowed tails
as they descend in flight.[74] Mag