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The Fijian crested iguana (Brachylophus vitiensis) is restricted to tropical dry forest habitat and has been extirpated from over 80% of its original range primarily because of habitat destruction. A large population on Yadua Taba island has been proposed as a source for iguana translocations. This study aimed to determine the dietary and habitat requirements of the herbivorous B. vitiensis on Yadua Taba to identify essential tree species. Between September 2005 and June 2006 we examined the diet of B. vitiensis using faecal analyses, while perch preferences were examined using field surveys. Faecal analyses identified 26 plant species in the diet of B. vitiensis, while field surveys recorded iguanas in 33 tree species. The most common diet species largely overlapped with the most common perch species. There were no major seasonal shifts, sex differences, or age-class variations in diet or perch preferences. These results suggest that while B. vitiensis occurs in and consumes several plant species on Yadua Taba, it is primarily dependent on only a few species. To improve translocation success, future translocations of B. vitiensis need to ensure that these important tree species are present at new sites.

Wildlife management, particularly the conservation of threatened species, often involves habitat management and an understanding of species preferences. Much ecological data used to establish rare and endangered species distributions and/or habitat associations exists in the form of point counts which often violates the assumptions of commonly used statistical techniques. In this study, the spatial distribution and habitat preferences of an endangered, endemic frog (Platymantis vitianus — Fiji ground frog) and an introduced toad (Rhinella marina — cane toad) were observed and mapped on a 60 ha island using a grid of 232 sampling points with 50 × 20 m spacing. The Spatial Analysis by Distance Indices (SADIE) analytical tool demonstrated that despite the wide range of habitats present on Viwa Island, both ground frogs and cane toads displayed clear and defined macrohabitat preferences. Whilst both species showed a strong preference for Inocarpus fagifer forests, there was little overlap in other habitat types with the ground frogs preferring more densely vegetated forest habitats and cane toads preferring more open habitat types close to both permanent and temporary water sources. Within the I. fagifer forests, there was no evidence of overlap in the distributions of the two species. The spatial pattern evident indicates that cane toad and ground frog populations co-exist, probably due to similar habitat preferences. However, a more detailed study on the interactions between the two species within their natural environment is needed to determine the nature and magnitude of the impact of the cane toad on the ground frog.

Tropical dry forests are a unique and threatened ecosystem in the Pacific and globally. In Fiji, the endangered Fijian crested iguana (Brachylophus vitiensis) is endemic to tropical dry forests. Yadua Taba Island contains one of the best remaining stands of tropical dry forest in the Pacific along with the largest (and only secure) population of B. vitiensis in Fiji and has been proposed as a translocation source for iguana conservation. In this study we determined the major vegetation types on Yadua Taba and identified forest habitat preferences of B. vitiensis to (1) characterize the island's habitats for tropical dry forest regeneration monitoring and (2) understand which forest types are preferred by iguanas for future translocation projects. Vegetation data were collected using reconnaissance, entitation, line transects, and aerial photos. Iguana abundance data were collected by nocturnal surveys of permanent transects. Six major vegetation types were identified of which tropical dry forest was the largest (46% of the island), followed by a combination of rocky cliff-shrubland/grassland vegetation (26%). Our conservative estimate of B. vitiensis population size on Yadua Taba is 12,000 iguanas, the majority of which occur in tropical dry forest. Superabundance of the dry forest understory tree Vavaea amicorum, the favorite fruit species of iguanas, may help account for the high density of iguanas observed. These results highlight the ecological link between tropical dry forest and B. vitiensis and emphasize the importance of rehabilitation or conservation of tropical dry forest habitat in potential iguana translocation sites as part of the management plan for B. vitiensis throughout the Fiji Islands.Tropical dry forest generally occurs in seasonally dry tropical regions where the average annual rainfall is less than 2,000 mm. In addition, tropical dry forests usually experience dry seasons (monthly rainfall < 100 mm) that stretch over 3 months or more (Mooney et al. 1998). In the Pacific, tropical dry forest has been recorded from Australia, New Guinea, the Solomon Islands, Vanuatu, New Caledonia, Fiji, and Hawai'i (Keppel and Tuiwawa 2007). Due to a combination of factors including fire, grazing by goats, introduction of invasive plant species, and clearing for agriculture (e.g., sugarcane, coconut, and pineapple plantations), very few, usually small, patches of tropical dry forest remain in tropical dry areas. As such, tropical dry forests are now considered one of the most endangered tropical ecosystems globally ( Janzen 1988, Lerdau et al. 1991 One of the best examples of tropical dry forest in Fiji and in the Pacific is found on Yadua Taba Island, a National Trust of Fiji Reserve in the northwest of Fiji. Over the past 25 yr, goats have been removed from the island, fires have been banned, and anthropogenic activities greatly restricted, which have increased the extent and improved the condition of tropical dry forest on Yadua Taba. In addition to having the only protected tropical dry fore...

The flora and vegetation of an area in north-eastern Vanua Levu that is part of Fiji's last major system of mesic forest were studied and revealed a mosaic of vegetation types, including mesic sclerophyll forest, transition forest, stunted Dacrydium nidulum forest, mangrove forest, montane forest, brackish and freshwater wetlands, and disturbed landscapes. This is much more diverse than indicated by the previous "dry forest" label. The flora comprises more than 268 native species, several of which are rare or narrowly distributed. Relatively large and undisturbed stretches of vegetation and the presence of rare and novel species and vegetation types suggest that the landowners should be given every possible assistance in protecting this unique landscape.