60 LAMPRONESSA SPONSA 



eleven centimeters suited his Carolina Ducks best. In Audubon's account, holes 

 over deep swamps, above cane-brakes, or on broken branches of high sycamores, 

 seldom more than forty to fifty feet from the water, are mentioned as the most 

 usual sites. 



Among the Carolina Ducks studied by Mr. Dixon in California, the narrowest 

 opening chosen measured just three and one eighth inches, but it was eight inches 

 high. In one case when the opening was both small and irregular, he found that the 

 female had actually cracked the shell of an egg still in the oviduct! The cracks were 

 "sealed over" by the time the egg was laid and the egg itself proved to be fertile. 

 I must say that I should have had difficulty in believing the explanation offered for 

 these cracked eggs, had not Major Allan Brooks told me of exactly similar instances 

 with Buffle-head Duck eggs in British Columbia. 



There are one or two rather doubtful records of Carolina Ducks and Hooded Mer- 

 gansers nesting in the same cavity (Boardman, 1903; R. M. Anderson, 1907). 



No doubt individual pairs breed in the same tree year after year, when unmo- 

 lested. We do not, of course, know whether the male is always the same. All I can 

 say is that in my established breeding stock, I scored disastrous results when, for the 

 sake of improving fertility, I one winter substituted a lot of strange males. 



The nest-cavity is often several feet in depth and the nest itself is composed of 

 rotted debris of wood, dry leaves, sometimes feathers of birds of other species, and 

 down from the breast of the female, but material such as sticks and leaves is not 

 brought to the hole. Audubon noted that when the nest was placed in the broken 

 branch of a tree it could easily be observed from the ground on account of the 

 feathers and other material about it. It is said that the feathers of domestic fowl 

 have at times been utilized. 



According to my own observations, confined Carolina Ducks begin laying in 

 Massachusetts from April 24 to May 5, depending on the variations of the season. 

 Wild birds in the same locality nest somewhat later but the species is always an 

 early breeder, from early March in its southern haunts to late May or early June in 

 the northern. In Cuba, where of course it is undoubtedly entirely resident, Dr. 

 Thomas Barbour found them nesting as early as February. Cooke (1906) mentions 

 young found in northern Florida, March 19, 1877 (!). Audubon found them pairing 

 about the first of March in Louisiana and Kentucky, sometimes a fortnight earlier, 

 and in Arkansas newly hatched young have been collected on April 4. Beyer, Alli- 

 son, and Kopman (1907) give early April as the beginning of the nesting season in 

 Louisiana. In Missouri young were found in the second week in May (Widmann, 

 1907). Farther north, in Minnesota and Michigan, eggs are laid from the end of 

 April till the beginning of May (Hatch, 1892; Barrows, 1912). At Cumberland 

 House, Saskatchewan, a nest and one egg were taken in June, but the northernmost 

 record for the species is one of a nest and two eggs taken at Fort Providence, Great 



