Microlophus occipitalis (Peters, 1871)

Taxonomic Classification

The knobbed Pacific iguana, Microlophus occipitalis, is classified as a small lizard.

Size

Its typical snout-vent length, measured from the tip of the snout to the start of the tail, ranges from 50 to 80 mm (2.0 to 3.1 inches).

Geographic Range

This species primarily lives along the coast of western Peru and Ecuador.

Habitat

It can occupy a wide variety of microhabitats including deserts, lomas, and beaches.

Thermoregulation Behavior

The lizard changes its preferred location throughout the day to regulate its body temperature: in the morning, it favors open areas with access to sunlight; at midday, it shelters in bushes, fallen logs, or abandoned buildings; and at night, it rests between rocks to maintain its ideal body temperature.

Territoriality

Knobbed Pacific iguanas are generally not territorial, and multiple males and females can be found together or clustered in the same area.

Male Aggression Exception

The only exception occurs when two large, aggressive males share the same space.

Aggressive Male Interaction Outcome

This situation is not tolerated, and usually results in one male leaving the area.

Territory Overlap Pattern

Because of this, territory overlap only occurs when smaller, less aggressive males live near a large, aggressive male, and never when two large, aggressive males occupy the same location.