70 LAMPRONESSA SPONSA 



days, is to take from each nest every day all except one egg, for in the competi- 

 tion among different females eggs are often pushed out of the boxes and broken. In 

 confinement the males are more or less polygamous, the females probably monoga- 

 mous. 



Eggs are usually set under hens, selection of a smallish mother being important, 

 and about twelve or thirteen eggs are given to each mother. One year I allowed a 

 Mallard to hatch thirteen Carolina Ducks in a pen built across a small brook and in 

 this case every duckling that hatched was reared to maturity. This is quite a differ- 

 ent experience from that of Heinroth, who did not believe that the female Mallard 

 would respond to the call or appearance of young Carolina Ducks. 



Mandarins and Carolina Ducks get along together very well and in my opinion 

 never hybridize. This point is of such interest that I must go into it a little more 

 fully. Suchetet (1889) cites several instances from the year 1850 on, and claims to 

 have seen one. Klein (1891) writes of the rearing of such a hybrid in the Copenhagen 

 Zoological Gardens. Since that time, notwithstanding the fact that the two species 

 have been almost always kept together, no actual hybrid has been described, 

 although Finn (1904) mentions a doubtful one which did not reach maturity. Hein- 

 roth (1911) made special efforts through a German breeder to secure fertile eggs be- 

 tween the two species and always failed, and I h4ve never heard of such a hybrid 

 being raised in this country. This physiological antagonism and the various rather 

 different traits, all point to a not very close relationship, in spite of the great simi- 

 larity of the females. 



In my pond I usually kept a slight excess of female birds, but this was offset by 

 the regular visits of several wild males during the laying period. Wild females never 

 came to the pond at this time. 



Nest-boxes can be of almost any style, but better than the artificial homes I found 

 the huge, partly hollowed, and irregular trunks and roots of several old willow trees. 

 These hollows, connected with the ground by little "duck ladders" and arranged 

 with suitable floors of soft punk or sod, served admirably and were almost always 

 the favorite nesting sites. Boxes about a foot square, and with holes four or five 

 inches in diameter, set up on posts five feet above the ground or water were nearly as 

 good. In these the nest of hollowed sod or other material may be only two or three 

 inches below the opening, or it may be at the bottom of a box two or three feet deep. 

 It makes very little difference. Neither does the position of the nest-box in the pond 

 seem to matter a great deal, although I always liked to have as great a variety as 

 possible, some high, some low, some hidden in dense willow sprouts, and some in 

 exposed situations. I also provided a number of burrows made from six-inch tile 

 pipe which led from near the edge of the water back into a nest-box sunk into the 

 ground with only its hinged lid showing on the surface. At times these were eagerly 

 patronized but at other times almost neglected. In different years my flock seemed 



