Reptiles
Fiji Banded Iguana
Brachylophus fasciatus · also called Fiji banded iguana, South Pacific banded iguana
A Fiji banded iguana can shift its own colouring mid-encounter, darkening its pale bands during a territorial dispute or courtship display in a way that seems to broadcast mood to nearby iguanas. Found only on a handful of South Pacific islands, it now faces predators its evolutionary history never prepared it for: rats, cats, and mongooses that arrived with people.
Overview
The Fiji banded iguana, Brachylophus fasciatus, is a vividly green, pale-banded lizard restricted to a limited number of islands in Fiji and nearby South Pacific island groups. Living mostly in the forest canopy, it feeds on leaves, flowers, and fruit, moving carefully through branches on long, gripping toes.
Bands that shift, predators it can’t outrun
Males intensify their banding during social encounters, but the species has no natural defence against introduced mammalian predators that now threaten eggs and young across its range. It is closely related to the even more critically endangered Fiji crested iguana.
Status
Endangered and decreasing — habitat loss and introduced predators are driving real declines, with predator control and captive breeding now central to its conservation.
Fiji Banded Iguana: common questions
How can you tell a Fiji banded iguana apart from a Fiji crested iguana?
The two species are closely related but differ in specific banding pattern and prominence, along with some differences in overall build and the presence and size of a dorsal crest, and they also generally occupy somewhat different specific islands within the broader Fiji island group, though both are restricted to a similarly limited South Pacific range and both face serious conservation concern.
Why do male Fiji banded iguanas change their colouring?
Males can darken or intensify their normal green-and-white banding pattern during territorial disputes with rival males or during courtship interactions with females, a temporary physiological colour change thought to communicate information about mood, dominance, or reproductive condition to other iguanas nearby, functioning as a visual social signal rather than a fixed permanent trait.
Why are introduced predators such a serious threat to this species?
The Fiji banded iguana evolved in isolation on South Pacific islands without significant native mammalian predators, so it has no strong natural evolutionary defences against introduced mammals such as rats, cats, and mongooses, which can prey heavily on iguana eggs and young in particular, making these relatively recently introduced predators a disproportionately serious threat compared with the natural predation pressures the species evolved alongside.
What is being done to help the Fiji banded iguana recover?
Conservation efforts for the species include predator control programmes aimed at reducing the impact of introduced rats, cats, and mongooses on some islands, along with captive breeding programmes intended to maintain assurance populations and potentially support future reintroduction efforts, reflecting a broader conservation strategy also used for the closely related and even more critically endangered Fiji crested iguana.