Mr. T. Ayres on the Ornithology of Transvaal. 295 
Potchefstroom, was referable to the northern A. minuta; 
but having recently reexamined this specimen, and compared it 
with numerous examples both of A. minuta and of A. podiceps , 
I am disposed now to refer it to the latter species, and to 
believe that A. minuta has not been satisfactorily identified 
as a native of South Africa. The two species (or rather sub¬ 
species) are, in fact, very closely allied, and, when in imma¬ 
ture plumage and not sexed, cannot always, as it seems to 
me, be discriminated with certainty. 
It may perhaps be useful to record the following memoranda 
which I have noted with reference to these two races of Little 
Bitterns :—The adult males of A. podiceps have the sides of 
the head and also the sides and back of the neck of a vinous 
brown, with more or less of a rufous tinge, whilst the corre¬ 
sponding parts in the adult males of A. minuta are of a 
somewhat pale fawn-colour, which is occasionally suffused 
with a very slight tinge of grey. The adult females of both 
species have the sides and back of the neck of a rufous 
brown, but the rufous tint is decidedly deeper and richer in 
the females of A. podiceps than in those of A. minuta , and 
both in the females and immature birds there is a general 
tendency in the southern race to exhibit a slightly deeper 
tint on the brown portions of the plumage than is usual in 
the more northern species. Except as above mentioned, I 
do not find that the two races differ in coloration; but the 
average dimensions of specimens of A. minuta are slightly 
larger than those of A. podiceps , the measurements of male 
birds of both species being usually a little in excess of those 
of the females, which makes it needful to compare individuals 
of the same sex in discriminating the two races. 
The following measurements (in inches and decimals) have 
been taken from specimens in the collections of my son, Mr. 
J. H. Gurney, Jun., and myself, and from others kindly lent 
me by Canon Tristram, Mr. Dresser, and Mr. Seebohm; the 
examples of A. podiceps are all from Transvaal, except one 
adult male in my collection from the Gaboon, which is the 
most northern example of the southern race with which I am 
acquainted. 
