Yong, Ed. “Why Are Bird Eggs Egg-Shaped? An Eggsplainer.” The Atlantic. Atlantic Media Company, 22 June 2017. Web. 28 June 2017.

“You Are Here, DNR Wildlife & Habitat Wildlife Species Amphibians & Reptiles.” DNR – Green Frog (Rana Clamitans). Michigan Department of Natural Resources, n.d. Web. 29 June 2017.

Image Attributions

Ostrich walking
By Christiaan Kooyman (Own work) [Public domain], via Wikimedia Commons

Swift egg
By Didier Descouens (Own work) [CC BY-SA 4.0 (], via Wikimedia Commons

Ostrich egg by Raul654

By Rudraksha Chodankar (Own work) [CC BY-SA 4.0 (], via Wikimedia