ABSTRACT
The members of the Genus Pygoscelis , Pygoscelis adeliae, P. papua and P. antarctica, the adelie, gentoo and chinstrap penguins respectively, seem to have a post-hatching development of their erythroid blood picture that is rather unique to the group. The peripheral blood erythroid picture of the well known Coturnix coturnix japonica from hatching through the first two weeks of life has been documented by R. P. Gildersleeve et al. The development of blood oxygen transport, a key process supporting aerobic energy metabolism is consequently of pertinent interest to ornithologists. Hematocrits of both sexes of wild, free-living, adult Falco sparverius American kestrels declined with the time of day that the blood sample was taken. Chickens that are forced into molt develop significantly increased hematocrits and hemoglobin levels. The relationships of the hematocrit and mean cellular hemoglobin concentration with the egg-laying cycle of brown leghorn hens were investigated by J. U. Bell et al.
