196 
FRANCIS H. HERRICK 
tration of which is figured in the work quoted above (pi. 5, fig. 3). 
This egg, which was taken in Montana, by Bendire, June 25, 
1885, is particularly interesting since it not only illustrates a 
sporadic variation in color, so marked in the European cuckoo, 
but also because its owner, when first disturbed on June 22, built 
a new nest and transferred this egg to it in a space of time not 
exceeding two days. The occasional transference of the egg from 
nest to nest, after the first has been discovered, had been noted 
by other observers, but we should desire fuller evidence before 
accepting the fact that the young are also moved about in a 
similar manner. At all events this undoubted transfer of egg in 
bill, however rare, is a very important fact in enabling us to 
evaluate the peculiar instincts of the European cuckoo. 
7. BEHAVIOR OF BROODING CUCKOOS 
The nest (no. 3) here referred to was placed on one of the whorls 
of a small pine sapling, about three feet from the ground, and 
when found on July 19, 1909, contained three incubated eggs, and 
one young bird at least twelve hours old. The conduct about to 
be described, with greater or less variation, is characteristic of 
many brooding birds, and illustrates the depression of fear which 
follows the rise of the brooding instinct. 
When the sitter, which we assumed to be the female, was 
approached to within a distance of five or six feet, she slid off 
quietly, and with tail spread, flying low, lighted in a small tree 
close by, where she remained for some minutes, ducking head and 
flipping tail constantly; she then disappeared, and gave the fam- 
iliar alarm, at times sounding like koor-uck-uck-uk, or like kur- 
ut-ut-ut, which no attempt at syllabication can perfectly repre- 
sent. At this nest the sitting bird had already acquired the habit 
of facing in a definite direction, and this position was steadily 
maintained during the nine successive days that observation 
lasted. 
On the day following we again tried to ascertain how near we 
could approach the sitting bird without disturbing her, by moving 
