First Record of a Komodo Dragon Island Population in Longos Island

 

Neither the survey conducted by Auffenberg (1981) in 1971 not the more recent study carried out by Ciofi and de Boer (2004) in 2002 reported the presence of Komodo dragons on the island of Longos. We successfully captured images of Komodo dragons on 10 cameras out of 23 camera trap locations. This is the first record of a Komodo dragon island population so far unknown to the international community and national authorities. 

Longos Island is located 500 km off the coast of northern Flores, between the bay of Terang and the village of Bari. It has an area of 478 ha and harbours four hamlets with a total population of 1,000 inhabitants, mostly fishermen. Beside a small teak and lamtoro plantation, there is limited agriculture and relatively healthy dry deciduous Monsoon forest and Mangrove forest. Longos is not part of the Flores nature reserve network. We also found 24 mound nests of which 15 with sign of activity by either orange-footed scrub fowls or Komodo dragons. Female dragons use three types of nesting grounds: hillside nests, ground nests, and mound nests initially built by the orange-footed scrub fowl, Megapodius reinwardt (Jessop et al 2004). Komodo dragons were found to nest in all three possible nest types in Komodo national park; however there was a significant trend towards females (62%) nesting in mound nests.

Mounds are volcano-shaped, have an average length of 10.4 ± 2.0SE m, a width of 9.6SE ± 1.8 m, and a height of 0.9 ± 0.3SE m and are constructed primarily on sandy or loamy soils in open forest areas with a minimum of overhead cover. Active scrub fowl mound nests are distinguished from active Komodo dragon mound nests chiefly by the amount of debris and recent diggings that occur, particularly during August and September. This can be determined as orange-footed scrub fowls nest earlier in the year, with eggs recorded from January until April. Moreover, megapode nests tend to incorporate vegetative debris into the mound and the chambers into which the birds oviposit. 

Active Komodo dragon nests will be confirmed by possibly deploying camera traps from June to October in order to record digging activity by females and/or female association with the nest. Females guard their nests for approximately the first 2-3 months after laying, remaining in close proximity to the incubation chamber. Continued monitoring could provide valuable data to plan long-term conservation of Komodo dragons on Longos Island.

Based on a very preliminary survey, we did not find evidence of deer on the Island. Komodo dragons may rely on smaller prey items such as fruit bats, scrub-fowls, long tail macaques, rats, lizards, geckoes and snakes. We recorded a sizable flying fox population roosting on mangroves. The findings of flying fox remains in Komodo dragon droppings and a consistent amount of macaque faeces with respect to large ungulates may be an indication of a shift in main diet components of Komodo dragons on small islands with respect to other mainland Flores and Komodo National Park populations.

Finally, we recorded 13 sightings of the yellow crested cockatoo (Cacatua sulphurea). Further survey, specifically targeting bird species may be needed in order to quantify size and population dynamics of protected avifauna.