7 8 Jotirnal of Travel and Natural History 



as the male, while the gorgeous chatterers, manakins, tanagers, 

 and birds of Paradise, as well as our own blackbird, have mates so 

 dull and inconspicuous that they can hardly be recognised as the 

 same species. 



This anomaly can, however, now be explained by the influence 

 of the mode of nidification, since I find that, with but very few ex- 

 ceptions, it is the rule — tJiat when both sexes are of strikingly gay 

 and conspicuous colours, the nest is of the second class, or such as 

 to conceal the sitting bird; while, lohenever there is a strikittg con- 

 trast of colours, the male being gay and conspicuous, the female dull 

 ajid obscure, the 7test is open and the sitting bird exposed to view. 

 I will now proceed to indicate the cliief facts that support this 

 statement, and will aftenvards explain the manner in which I con- 

 ceive the relation has been brought about. 



We will first consider those groups of birds in which the female 

 is gaily or at least conspicuously coloured, and is in most cases 

 exactly like the male. 



I. Kingfishers (Alcedinidre). In some of the most brilliant 



species of this family the female exactly resembles the male; 

 in others there is a sexual difference, but it rarely tends to 

 make the female less conspicuous. In some the female has 

 a band across the breast, which is wanting in the male, as 

 in Halcyon diops. In others the band is rufous in the 

 female, as in several of the American species ; while in 

 Dacelo gaudichaudii, the tail of the female is rufous instead 

 of blue. In most kingfishers the nest is in a deep hole in 

 the ground ; in Tanysiptera it is said to be in a hole in 

 the nests of termites, or sometimes in crevices under over- 

 hanging rocks. 



II. Motmots (Momotidee). In these showy birds the sexes are 



exactly alike, and the nest in a hole under ground. 



III. Puff-birds (Bucconidoe). These birds are often gaily 

 coloured ; some have coral-red bills ; the sexes are exactly 

 alike, and the nest is in a hole in sloping ground. 



IV. Trogons (Trogonidai). In these magnificent birds the 

 females are generally less brightly coloured than the males, 

 but are yet often gay and conspicuous. The nest is in a 

 hole of a tree. 



V. Hoopoes (Upupidae). The barred plumage and long crests 



of these birds render them conspicuous. The sexes are 

 exactly alike, and the nest is in a hollow tree. 



