124 DENDROCYGNA VIDUATA 



Courtship and Nesting. In spite of the extensive literature on this species there 

 is extraordinarily little known as to its sexual life, and particularly as to the location 

 of its nest. The display is described by Heinroth (1911) as simple and very similar 

 to that of geese, Comb Ducks, and the Mute Swan. There is a reciprocal invitation 

 in the shape of an oft-repeated dipping and lifting of the head and neck. In the 

 postlude (following the mating act) both sexes erect themselves, and facing toward 

 each other, lift the wings, occasionally even spreading them upward. This display 

 phenomenon is characteristic of the whole group of Tree Ducks, and has little in 

 common with corresponding behavior among the true ducks. 



Regardless of the fact that this bird is one of the most plentiful, if not the most 

 plentiful, of all tropical ducks in both Africa and South America, actual records of 

 the finding of nests are extremely rare. Most travelers confess that they have hunted 

 diligently during the nesting season, without making a single find. About all the in- 

 formation which they contribute has been drawn from the natives. P. L. Sclater and 

 Hudson in 1889 admitted that they knew nothing of its nesting habits in South 

 America. Kerr (1901) says that they nest in palm trees in the Gran Chaco region of 

 Argentina. In Dutch Guiana the Penards (1908-10) state that the birds usually, 

 but not always, nest in hollow trees, sometimes at considerable altitudes. 



Not a single observer in Africa has ascertained anything as to its nesting in trees 

 and Reichenow (1874; Reichenow and Liihder, 1873) is of the opinion that it prob- 

 ably nests in the rushes near water, and that it is certainly not dependent on trees. 

 Von Heuglin (1873) holds a similar view. In Madagascar it has been reported as 

 nesting even on hills among grass (Sibree, 1892). 



When all is said and done, we know less about the average nesting site of this 

 bird than we do about that of any other common species of duck. 



Like all tropical species the White-face has an extremely irregular and extended 

 breeding period. Eggs were found in East Africa early in March (Bohm, 1885) and 

 in western Liberia in August (Biittikofer, 1885). In Togo, also, half-grown young 

 were found in August and September (Reichenow and Liihder, 1873). 



The clutch is given as consisting of from eight to twelve. In one case twenty-two 

 is the number recorded (Antinori and Salvadori, 1873), probably representing the 

 efforts of two females. The eggs measure 45.5-48 by 36-37 mm. and are yellowish 

 white in color (Reichenow, 1900). 



One of the most interesting characteristics of this species (which, however, ap- 

 plies also to Dendrocygn a bicolor) is the participation of the male in the duties of in- 

 cubation. Biittikofer (1885) speaks of a male being taken off a nest by a native, and 

 Heinroth (1911) gives ample evidence supplied by German bird fanciers that the 

 male assumes the principal part in the work of incubation. At the beginning the 

 male seems to incubate alone. On the other hand, Pocock (London Field, January 

 9, 1915) cites an instance of a pair that nested on Lord Lilford's estate. In this case 



