178 



DuBois, Nesting of the Horned Grebe 



r Auk 

 LApril 



faint voice, at the other side of the water, was detected and was 

 followed several times, but when its author was finally lo- 

 cated it proved to be not a Grebe but a recently hatched Sora 

 Rail. 



The next morning, although the sun shone upon the nest, the 

 eggs were cold and the fetuses in both of them were dead. No 

 birds were seen. My last visit, on the evening of July 24, yielded 

 no further result. But I noted now, that there was no water 

 around the nest. It was stranded upon a mud-bar. This was 

 undoubtedly the cause of forced abandonment of the nest. The 

 Grebes were unable to reach it by a water route, and no other mode 

 of travel was possible to them. A search around the water area, 

 now very small and shallow, gave no further evidence. The 

 Grebes were never seen again. 



In reviewing the account of these observations certain groups 

 of data suggest themselves for summarization: 



It is interesting to note that only six days elapsed between the 

 removal of the first set of eggs and the deposition of the first egg 

 in a new nest. 



The period of incubation is twenty-four or twenty-five days, as 

 shown in the following table of dates, noted at the second nest: 



It will be observed that the fourth egg was alive and on the point of 

 hatching, twenty-eight days after it was deposited, but this can- 

 not be considered normal, since the egg had been deprived of the 

 parent heat for several days. It seems remarkable that the fetus 

 survived the cool nights. 



