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Varanus olivaceus feeding
in a Microcos tree – Polillo,
May 2005. From video by Simon Normanton/ Steel
Spyda.
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Daniel Bennett (2014) used camera traps and direct observation to
investigate the foraging behavior of the butaan, . This lizard is an obligatory frugivorous monitor
lizard restricted to Luzon, Polillo and Catenduanes islands in the northern
Philippines. Its diet consists almost entirely of fruit and snails. Auffenberg studied
this species and stated it feeds exclusively on fallen fruit from the forest floor
and rarely, if ever, took fruit from trees. However, a ten year study of the
species on Polillo Island in Quezon Province found no evidence to support this
assertion that the lizards typically forage on fallen fruit. Bennett gather
evidence indicating that the butaan normally climbs fruiting trees of all
species and picked the fruit directly from branches or syncarps. The study was
carried in and around the Sibulan Watershed Reserve, Polillo Island Quezon Province
in primary and secondary lowland dipterocarp forest.
Bennett found the lizards spend as little time on the ground as possible.
However they never overnight in fruiting trees and suggests this is probably because
the trees provide neither suitable hollows nor dense thickets in which to
shelter. The lizards spent as little time as possible in fruiting trees before
returning to larger trees that provide greater protection from predators, and
that they appear to approach fruiting trees directly without searching for
fallen fruit below the canopy makes it unlikely that they would preferentially
take fruit from the ground. However, snails are probably found and consumed on
the forest floor rather than in trees.
Citation
Bennett, D. (2014) The Arboreal Foraging Behavior of the Frugivorous
Monitor Lizard
Varanus olivaceus on
Polillo Island.
Biwak, 8(1), 15-18.