Edward Narayan

Monitoring the reproductive success of endangered Fijian ground frog on Viwa Islands

Fijian ground frog on a branch

Fijian ground frog on ground

LocationCountryCategoriesDate
ViwaFijiAmphibians, Australasia15 Apr 2008

Fijian ground frog Platymantis vitianus (Anura, Ranidae) is currently listed as endangered by the IUCN (World Conservation Union) standards. Despite the rapid in-situ declines of P. vitianus, scientific knowledge on their reproductive biology remains anecdotal. This unique project involves an annual assessment of the variation(s) of reproductive status of P. vitianus on Viwa Island (located 900m east off first mainland Viti Levu), on which small mammalian invasive species eradication projects are currently underway (Morley, 2007).

A potential benefit to the local people of Viwa Island will be recruitment of field assistant(s), who will assist in conducting field surveys. A primary objective of this project is to find out the reproductive variation(s) of P. vitianus between breeding and non-breeding seasons, potential in-situ nesting areas, number of eggs incubated, hatchability rates, number of gravid females present at invasive cane toad Bufo marinus [CT] accessible habitat site vs. CT inaccessible “out of bounds” habitat site and to identify possible physical and biological factors affecting the incubation and hatchability rates of froglets.

This project incorporates various scientific tools for data analysis and it carries out three main comparisons including (a) Variation in the total number of P. vitianus from each of the categories i.e. adult male, adult non-gravid female, adult gravid female, metamorphs and froglets in both selected habitat locations i.e. cane toad accessible and cane toad inaccessible sites, over a twelve month period. (b) Variations in reproduction i.e. comparison of the total numbers of gravid females, metamorphs, nesting areas between breeding vs. non-breeding season (if found) and between the two habitat locations. (c) Calculate the average monthly growth rates of as many froglets found in the two habitat locations.

Ultimately this project will provide a detailed account of the total number of potential nesting sites, egg clutches, number of eggs per clutch and egg, froglet biometrics of P. vitianus found in both natural habitat sites. This annual project will provide substantial new baseline scientific data on reproductive status of P. vitianus on Viwa Island and it will help determine whether this unique frog has a high rate of reproductive failure. Furthermore, it will provide new information on the possible effect(s) of introduced cane toad on the reproductive efforts of P. vitianus. The main benefit of knowing more about the reproductive status of P. vitianus will be towards its overall conservation and safeguarding it from extinction crisis.

For more information contact edward_nryn@yahoo.com

Project Update: May 2008

A “sevusevu” - traditional Fijian presentation was conducted on Viwa Island on the 20th of April, 2008. This ceremony is an integral component of the indigenous Fijian tradition. A large bundle of Kava (traditional Fijian drink) root was presented to the “Ratu” -chief of the Viwa Islands. This presentation was observed by the research scientists from the University of the South Pacific (USP), Fiji. The presentation was given to the “Ratu” on our behalf by the “Turaga-ni-Koro” -village spokesman. The village spokesman informed the chief about the overall objectives of the project its benefits to the local people and the conservation of endangered Fijian ground frog.

At the end of the ceremony, the chief of the village accepted the Kava root (this indicates that he accepted our request and granted permission for the project to be conducted on Viwa Islands). This event marks the start of our project on Viwa Islands.

Project Update: July 2008

Summary: The two field sites on Viwa Island have been selected within the forested landscape. A general nightime survey revealed that both cane toad and P. vitianus were occupying the same terrestrial habitats. Cane toads were manually removed from site 1 and a fence was erected to prevent them from re-entering into this site. Site 2 had access to both cane toads and P. vitianus. A visual encounter survey [VES] for one night found 12 adult male and 12 adult female P. vitianus inside site one. Site two had 10 adult male and 10 adult female while total cane toads counted were 20 adult males and 25 adult females in site two. Two field assistants were assigned to carry out the surveys.


Other Projects in: