Animal Biology

Sperm whales (Physeter macrocephalus) produce sperm within their massive heads as part of their reproductive biology, but precise, population-level measurements of how much sper...

Orcas, or killer whales, are oceanic dolphins with a well-studied reproductive cycle that varies between wild populations and human-managed care. Understanding what happens when...

Macaroni penguins get their "yellow hair" from dense, flexible feather crests on their foreheads and around their eyes. These specialized feathers are not hair but structurally...

Jonathan is a famous Seychelles giant tortoise living on Saint Helena, known for his age and name rather than for private behaviors. This verified explainer outlines his species...

Albino moose do not have pure white antlers; their antlers are typically normal-colored bone covered by a layer of hair that can appear pale but is not pigmentless like true alb...