INTRODUCTION. xiii 



Gulls, the Herons, and many other large birds, all of which are more or 

 less conspicuous and make open nests. In most of these cases, however, 

 the birds are well able to defend themselves and their nests from enemies ; 

 but the more helpless species (as, for instance, the Sandpipers) seek safety 

 for themselves in flight, relying upon the protective tints of their eggs or 

 young. I shall, however, return more specially to this group of birds 

 when I treat on that part of the subject which concerns eggs and young 

 birds. We now notice a small group of 



Birds in which the male is less brilliant than the female, and which 

 nidificate in open nests. — The birds in this group are exceedingly few in 

 number, but are nevertheless very interesting. Let us take, for instance, 

 the Dotterel {Eudromias morinellus) ; although the difi'erences between 

 the sexes of this species are not very striking, they exist, and the female 

 is more showy than her mate : or, better still, take as examples several 

 of the Phalaropes [Phalaropus], where the females are more brilliant 

 in their nuptial dress than the males, the Common Cassowary {Casuarius 

 bennettii) or the Emu (Dromceus irroratus), a Carrion-Hawk [Milvago 

 leucurus) from the Falkland Islands, an Australian Creeper {Climacteris 

 erythrops), and an Australian Goatsucker {Eurostopodun albogularis), in 

 all of which the females are of more decidedly conspicuous colours than 

 the males, and the nests are open and exposed. Curiously enough we 

 find in all these cases that the male bird performs the duties of incu- 

 bation, and in several instances is known to show much more solicitude 

 than the female for the young ! We have, however, an exception to this 

 in the African Ostrich, where the male is more showy than the female; 

 nevertheless he performs the duties of incubation (Sclater, Proc. Zool. 

 Soc. 1863, p. 233). The Ostrich has few enemies; and this fact, together 

 with that of its peculiar manner of nidification, is probably the reason 

 that its plumes have had no check to their present development. It 

 is also worthy of remark that the young of probably all these birds, 

 instead of resembling the females, as is the case with most species, more 

 closely resemble the males, a circumstance which seems to prove abso- 

 lutely that sexual selection has been exclusively confined to the female in 

 these cases. 



Having now treated of those birds which rear their young in open nests 

 we pass on to the second great group, in which the nests are concealed, first 

 on our list being 



Birds in which both sexes are brightly coloured and which rear 

 their young in holes or covered nests. — One of the most striking 

 instances in our, for the most part, duU-plumaged northern birds is that 

 of the Kingfisher {Alcedo ispida) . The male and female are exactly alike in 

 colour, and both are adorned with the same refulgent dress. But how 

 does Nature shield the sitting bird during the nesting-period ? Why has 



