BIRDS 151 



of courtship. The mere process of selection affords no ex- 

 planation whatever of a special process of growth, occurring 

 regularly at every breeding season, and dormant during the 

 rest of the year. Mr. Bowker, as quoted in the Royal 

 Natural History, says, that the male Vidua paradisea enjoys 

 himself in a high wind, spreading out his tail like a fan, but 

 it is stated also that the Kaffir children often succeed in 

 running the bird down, because the nuptial feathers impede 

 his flight. The actual erection and display of the feathers in 

 courtship does not seem to have been observed. 



Many of the other families of Passeres consist of singing 

 birds, and in these the power of song is generally confined to 

 the males, and is associated with an absence of other secondary 

 sexual characters. In these cases the energy of the male 

 under the influence of sexual excitement has been exerted in 

 his voice, and this is the reason why the voice has developed 

 in the male and not in the female. 



In the Falconiformes or Birds of Prey sexual dimorphism 

 is slight, and this is in harmony with the fact that these birds 

 are monogamous, and both sexes take part in obtaining food 

 for their young. There is a slight difference between the 

 male and female Condor. The male has a small dull-coloured 

 comb of somewhat flat shape. I have not found any mention 

 of special habits related to this peculiarity ; perhaps the males 

 fight with one another, and in fighting strike at the top of 

 the adversary's head. 



In most of the members of the order the female is the 

 larger. This is well seen in the Sparrow-hawk. It does not 

 seem likely that this is due to the same conditions as in 

 Turnix and Bhynchcea, for generally hawks and falcons pair 

 together for the season, if not for life, and it has not been 

 stated that the female takes the initiative in courtship or 

 fights with rivals. The fact is probably due to greater activity 

 on the part of the female in capturing prey for her young, 



