46 ELEONOBA FALCON. 
and describes the old male as "black schistaceous grey." Professor 
Blasius, however, (Ibis, vol. ii, p. 432,) is given as an authority for 
stating that the eggs of the birds described by Heuglin as F. eleonorce, 
from the Archipelago of Dahalak, were those of F. concolor and not 
F. eleonorce. There is also a tendency on the continent towards the 
belief in the identity of the two birds. Swainson, however, who was 
a most accurate observer, in describing F. concolor, (Birds of Africa, 
vol. i, p. 112,) remarks that it is seldom we meet with a Hawk which 
can so readily be distinguished from all others by its peculiar "deep 
slate colour, somewhat paler beneath, and with a brownish tinge in 
some parts of the upper plumage, etc." 
Blasius maintains the perfect distinctness of the two birds in his 
list of 1861, and assigns F. concolor a European locality in Spain. 
Mr. Gurney writes, "There is no doubt as to the distinctness of F. 
eleonorce and F. concolor, the latter of which I have never seen from 
any European locality: both species occur in Eastern Africa and 
Madagascar." M.M. Jules Verreaux and O. Des Murs have both 
attempted to prove the identity of the two birds in the "Revue et 
Magasin de Zoologie," for 1862. 
In his "Richesse Ornithologique du Midi de la France," M. Jaubert 
describes four different plumages which he says the bird assumes 
during the first four years. — 
"First. — The young of the year, when the plumage resembles that 
of the Hobby. 
Second. — After the first year the head and all the upper parts be- 
come uniformly brown, without any red borders to the feathers; 
without the head marks or the reddish collar round the neck. This 
is the condition of the young as described by Gene", and is produced, 
according to Jaubert, by a partial moult and the wear and tear of 
the back feathers. 
Third. — After the second moult, when the bird is three years old, 
it assumes a livery in which "it may be recognised as the type 
represented in the "Fauna Italica" of Ch. Bonaparte, and of which our 
collections contain a large series, representing various grades of colour, 
bringing this bird by degrees to the fuliginous plumage, which is only 
a dress worn off down to the shaft, and this it will soon throw off 
to assume the plumage of the old bird, which is characterized by a 
dark brown colouring on all the upper part of the body, and by an 
analogous tint on all the anterior parts, the feathers of which are 
edged by a reddish border, with a spear-shaped spot on the flanks 
and sides. It is by the progressive diminution of this border that the 
bird becomes more and more brown and unicolorous." 
These stages of plumage are well illustrated by M. Jaubert, in a 
