32 PALCONID^. 
I have known a third egg laid in a nest from which one had 
been abstracted^ one having been left ; but whether the third 
egg was laid by the same bird is of course " not proven/^ Two 
eggs seem to be the usual number _, the pair being generally 
alike ; but those from different nests vary very much, some 
being blackish brown, others quite light, some almost round, 
others elongated. This Vulture is probably the foulest- 
feeding bird that lives, and is very omnivorous, devouring 
any animal substance, even all sorts of excrement ; nothing 
comes amiss to it. Sometimes I have seen them feeding on 
the sea-shore on dead fish thrown up by the tide. 
The adult birds are white, with black wings. 
The immature plumage is light brown, with darker vrings ; 
and, judging from birds which I have seen kept in captivity, 
they take three years to attain the adult plumage, though 
probably in a wild state they would not remain so long in 
their immature dress. 
Family Falconid^, 
4. Circus cyaneus, Linn. Hen-Harrier. 
Moorish. Bou basin (Father of beauty) . • Spanish. Cenizo. 
According to Favier this "is the least common of the 
Harriers near Tangier, being seldom met with.'^ 
On the Spanish side of the Straits, though a resident bird, 
the Hen-Harrier is most frequently seen invrinter; but their 
numbers fluctuate greatly. I observed more in the winter of 
1871-72 than at any other time, particularly about Casa 
Vieja, seldom, however, coming across an old male. 
The adults may be distinguished from C. macrurus by 
the pure white rump. The adult male, as in the two next 
species, is of a grey colour above ; the female is undistinguish- 
able on the wing from that of C. macrurus, both having and 
showing conspicuously the white upper tail-coverts. 
5. Circus pygargus (L.). Montagu's Harrier. 
Circus cineraceus auct. 
'^ This Harrier passes to Europe in March and April ; but 
some remain to breed near Tangier, where they are nearly as 
