How to Compare Reptiles & Birds

Although they look and behave differently, reptiles and birds have more in common than you might think. When we compare the two, it is often easier to find similarities than differences.

  1. Skin Covering

    • Maybe the most visible difference between reptiles and birds is what covers their skin. Reptiles are covered in hard scales and birds are covered in feathers. However, as N.S. Proctor and P. J. Lynch point out in their book "Manual of Ornithology," feathers and scales are similar in structure and origin. Most birds still have more typical scales covering their legs and feet.

    Warm or Cold-blooded

    • A principal difference between birds and reptiles is the method by which they regulate their body temperatures. Reptiles are cold-blooded (or ectothermic) and use their environment to adjust their temperatures. Birds are warm-blooded (or endothermic) and maintain their temperatures internally. However, in an article published in "Physiological Zoology", I.H. Choi, R.E. Ricklefs and R.E. Shea explain that many baby birds are ectothermic for the first few weeks of life and need their parents to maintain their high body temperatures.

    Heart Structure

    • The structure of the heart adds more confusion to the comparison between birds and reptiles. Lizards, snakes and turtles have a heart that has three chambers or compartments, while crocodilians and birds have a four-chambered heart. This is one reason that many scientists have grouped birds and crocodilians together.

    Parental Care

    • When separating these two groups, many people state that birds care for their young while reptiles do not. However in "The Evolution of Parental Care", T.H. Clutton-Brock reminds us that many reptiles do care for their young, including most crocodilians and some snakes.