AFRICAN YELLOW-BILLED DUCK 
119 
here and there in the shallows. Men were then sent about with long Cape wagon- 
whips with which they kept up a continual cracking noise nearly as loud as the report 
of a gun. This kept the birds flying to and fro over the ambuscades. 
Behavior in Captivity. The Yellow-bill was first introduced into England by 
the Earl of Derby, and was obtained by the London Gardens at the sale of the 
Knowsley collection in 1851. It bred first in 1859 and several times between that 
date and 1870. The young birds hatched in late May or June (P. L. Sclater, 1880). 
They were also hatched in the Rotterdam Gardens about 1870 (van Bemmelen, 
1872). It has bred freely in continental gardens and was often purchased for £4 per 
pair. Mr. Blaauw told me that he reared it on his estate at Gooilust, Holland, and 
I saw a fine stock there in the spring of 1922. The first winter after he got them from 
Africa he kept them indoors, but after that he found them sufficiently hardy to 
winter in his ponds. 
They have never been imported into America so far as I am aware. 
The Yellow-bill adapts itself admirably to life in confinement. It becomes very 
tame and breeds, according to Rogeron (1903), even more readily than the wild 
Mallard. In its relations to the female and to other males it is like the true Mallard. 
In the spring the male seeks out females of its own kind and of the Mallard indis- 
criminately. If the two species are not kept separate, crossings are inevitable. They 
will not use nesting boxes, but nest on the ground like wild birds. The clutch 
Rogeron found to be from ten to twelve. The birds were not particular about 
their food and in addition to the usual diet fed on acorns. Mr. Hubert D. Astley had 
a pair which nested for a second time in 1922, bringing out a late brood in Novem- 
ber, an unusual occurrence. They seem to be especially hardy and long-lived. One 
specimen, hatched and raised on Rogeron’s place, lived to be eighteen years old, 
and was given full use of its wings for several years, while in the London Gardens 
one lived to be 26 years and 7 months old, though the average of eight birds was 
seven years. 
Hybrids. There are no wild hybrids recorded as far as I have learned. In 
captivity it has crossed freely with Mallard and African Red-billed Ducks {Anas 
erythrorhyncha) , more rarely with the Spot-bill {Anas pcedlorhyncha) and also with 
the American Black Duck {Anas rubripes) (Poll, 1911). I saw a live specimen of this 
last cross in Mr. Blaauw’s gardens in 1922. 
