Spines

The Caudal Spines are positioned on the back of the neck near the base of the head. In large adult males the Caudal Spines are often extremely long. These spines greatly increase the appearance of the size of the animal. This helps the iguana in territorail bouts and helps them defend themselves against predators. A predator wouldn't want to go after prey that is big enough to hurt it.

This big male named Harry has some exceptional spines. Look how they help to increase his size appearance. Another maybe smaller male would not want to battle over territory or a female with this large male!