Fiji Crested Iguana

Appearance

The Fiji crested iguana is a large stocky lizard distinguished from the Fiji banded iguana by the presence of three narrow, cream to white colored bands on males, rather than the broader bluish bands of the latter species. These whitish bands often have chevrons of black scales close to them. ''Brachylophus vitiensis'' is distinguished by its larger size growing to 76 centimetres in length and weighing as much as 300 grams . It is further distinguished by the presence of a taller spiny "crest" on its back with spines as long as 1.5 centimetres running from the nape of the neck to the base of its tail, and its ability to rapidly change color from green to black when aroused. It uses this ability when threatened. Along with turning black it opens its mouth and lunges at its attacker.

When Fiji crested iguanas first hatch from their eggs they are dark green, but after several hours their skin becomes bright emerald green and narrow white bands can be seen along their body.

Their eyes are reddish orange or pinkish gold in color.

Naming

The generic name, ''Brachylophus'', is derived from two Greek words: brachys meaning "short" and lophos meaning "crest" or "plume", denoting the short spiny crests along the back of this species. The specific name, ''vitiensis'', is a Latin adjective derived from the Latin word for Fiji.

The species is closely related to the Fiji banded iguana and ''B. bulabula''. The genus ''Brachylophus'' has been suggested to be the descendants of a more widespread lineage of Old World iguanids that diverged from their New World relatives in the Paleogene. Alternatively, the ancestors of these iguanas may have rafted 9000 km west across the Pacific Ocean from the Americas, where their closest relatives are found.

The discovery of ''Brachylophus vitiensis'' began when Dr. John Gibbons of the University of the South Pacific was invited to the screening of the movie ''Blue Lagoon''. The director filmed part of the movie on a remote island and included shots of the native wildlife to enhance the feel of the movie, including a large colorful iguanid. Gibbons, who had been studying the Fiji banded iguana at the time, travelled to the island and identified it as a distinct species.

Distribution

The species is restricted to dry forest habitats, which is one of the most threatened vegetation types in the Pacific. It was once known from 14 islands in the western part of Fiji; however, recent surveys in the past two years have only confirmed the species on three islands: Yadua Taba, Monuriki, and Macuata. Yadua Taba holds the highest concentration of the species, containing approximately 98% of all individuals, which is estimated to be 6,000 animals. This is the only legally protected population, as Yadua Taba is a National Trust of Fiji reserve and lacks the feral goats which have destroyed the lizard's habitat on other islands.

Habitat

The species is restricted to dry forest habitats, which is one of the most threatened vegetation types in the Pacific. It was once known from 14 islands in the western part of Fiji; however, recent surveys in the past two years have only confirmed the species on three islands: Yadua Taba, Monuriki, and Macuata. Yadua Taba holds the highest concentration of the species, containing approximately 98% of all individuals, which is estimated to be 6,000 animals. This is the only legally protected population, as Yadua Taba is a National Trust of Fiji reserve and lacks the feral goats which have destroyed the lizard's habitat on other islands.

Reproduction

The breeding season occurs during the months of March and April, with courtship and mating commencing in January. The Fiji crested iguana is oviparous and has one of the longest incubation periods of any reptile at 189 days. Females guard the nest of four to six eggs, which is unusual for iguanids. Hatchlings emerge from their eggs in the rainy season and obtain moisture by licking wet leaves.

Food

Fiji crested iguanas are herbivorous feeding on the leaves, fruit, and flowers of trees and shrubs, particularly hibiscus flowers of the Vau tree . Captive hatchlings have been observed eating insects; however, adults will not.

Predators

The biggest threat this iguana faces is habitat loss due to fires, storms, agricultural development, and competition from feral goats. Goats were introduced to Yadua Taba in 1972 and numbered over 200 by the late 1970s. The vegetation on the island during this time was severely depleted by a combination of grazing and fires used to drive goats for ease of capture. After the discovery of the Fiji crested iguana, the island was declared a sanctuary and all but a few goats were removed and fires banned. As a result, the dry forest on the island has recovered to a great extent and is the best remaining example of dry forest Pacific. Invasive ''Leucaena'' trees threaten the regeneration of native food trees for the iguanas, but the government of Fiji has taken steps to eradicate the trees.

A secondary threat is introduced predators in the forms of rats, mongooses, and cats which prey on the iguanas and their eggs. Additionally the iguana has been hunted as a food source and for the illegal animal trade.

In 2002, five adult iguanas were stolen from the sanctuary, but Fiji Custom officers caught the smuggler before he boarded his international flight. Since this incident, tourist visits to the sanctuary have been prohibited and only researchers are permitted to visit the island. In order to protect iguanas in the sanctuary from diseases and parasites, it is not permitted to return to the island any lizard that has been removed.

Cultural

The Fijian name for iguana is "vokai", although some tribes call it "saumuri". Two tribes regard the iguana as their totem and as such its name is not allowed to be mentioned in the presence of women or the offender may be beaten with a stick. The majority of Fijians, however, are terrified of the crested iguana because of its behavior when threatened.