Allometric and Phylogenic Comparisons of Hematological Parameters between and within Birds and Mammals

Abstract As has been observed previously, there are no differences between class Mammalia and Aves for either packed cell volume (PCV)/Hematocrit (HCT) or hemoglobin concentrations using a much larger data-base - data from 357 mammalian and 323 avian species. However, the erythrocyte concentrations and size were respectively higher and smaller in mammals. There were marked differences for hematological parameters between taxa within both the Mammalia and Aves. For instance in mammals, PCV/HCT is low in both Afrotheria and Xenarthra. In contrast, PCV/HCT is highest in the order Chiroptera and greater in marine mammals (Cetacea and Pinnipedia) than in their respective related taxa, Artiodactylia and non-marine carnivores. In birds, there were differences between taxa for PCV/HCT, for examples between orders Anseriformes and Galliformes but none for the blood concentration of hemoglobin. There marked differences between mammalian and avian taxa for both erythrocytes concentration and MCV. Allometric relations are observed for PCV/HCT, blood concentration of hemoglobin, erythrocyte concentration and MCV across both birds and mammals. However, allometric relationships for PCV/HCT and MCV are seen in only some but not other mammalian and avian taxa