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Although no behavioral studies have been on this species, it is assumed to be very similar to its closest relative, Varanus olivaceus. All frugivorous monitors are highly secretive, and rarely seen through chance encounters. Gray's monitor has been documented spending several days at a time in the tops of fruiting trees, decending to the ground only to move to the next tree.
Varanus bitatawa is one of three species of primarily frugivorous monitor lizards (Subgenus: Philippinosaurus), all of which are endemic to the Philippines. This species exhibits a dark gray dorsal ground color overlain with bright yellow-gold dorsal bands, comprised of transverse series of ocelli. Tail with unbroken dorsal bands.
Varanus bitatawa has only recently been introduced to the scientific community, and consequently must be considered data-defficient when assessing its conservation. This species is targeted as a bush meat delicacy by local tribespeoples, and despite a relatively wide distribution, is likely highly impacted by harvest and habitat degradation.
Varanus bitatawa is designated as a CITES Appendix II species. This taxon is not currently threatened by extinction, but may become so unless trade or other factors are closely monitored.
Varanus bitatawa generally exhibits a dark gray to black dorsal ground color, overlain by highly contrasting bright yellow or golden yellow blotches and spots. Head and neck with irregularly arranged bright gold blotches ususally consisting of 1-8 scales, density of brightly colored scales incresing anterolaterally on head. Trunk generally patterned with a series of transverse bands comprised of variably-sized yellow to gold oscelli; bands may be interspersed with smaller irregular blotches; limbs colored similar to body, but often with less discernable bands, and gold coloration becoming more prominent distally; hands and feet primarily golden yellow, with irregular aggregations of black scales; digits variably banded golden-yellow, often with single enlarged yellow terminal scale sheathing the claw; tail with regular golden-yellow bands from insertion to terminus, with alternating black bands containing small irregular yellow blotches. Ventral coloration less variable, bright yellow; gular and nuchal regions slightly darker; limbs similar to body; hands and feet black, except for a variable number of golden-yellow terminal scale rows; tail uniform yellow ventrally. Tongue is pinkish gray, and the iris is brick red.
Varanus bitatawa is known only from central and northern portions of the Sierra Madre mountains of northern Luzon Island, Philippines. Based on the localities of the type series and photographic accounts, this species is expected to inhabit suitable habitat from the San Ildefonso Peninsula (Aurora Province), north through Isabela and Cagayan provinces to Peñablanca and Baggao municipalities.
As with the other two species of frugivorous monitors, Varanus bitatawa is a predominately arboreal species, spending vast amounts of time in the canopies of fruiting trees. During dry periods, it can be expected to transition to a more terrestrial lifestyle in search of a preferred secondary food source, snails.
The specific epithet for this species is derived from bitatawa, the Agta tribespeoples' common name for this species throughout much of its distribution.
Luzon Pleistocene Aggregate Island Complex
Varanus bitatawa is assumed to be a forest obligate (as has been documented with its closest relatives V. mabitang and V. olivaceus), and is heavily dependent upon unfragmented lowland and mid-elevation forests with sufficient stands of fruiting Pandanus, Canrium, or Ficus trees.
Superficially, Varanus bitatawa may be confused with species of Philippine water monitors (V. marmoratus, V. cumingi, or V. palawanensis) based on the presence of golden-yellow dorsal patterning, but can easily be distinguished from those species by characteristics of body size, behavior, and dietary preference.
Varanus bitatawa is likely a forest obligate, requiring relatively large tracts of intact habitat. Specifically, the protection of habitat which includes dense populations of this species' prefered fruiting trees (Pandanus, Canarium, and Ficus) will be essential for maintaining this species in the future.
The most severe threat to this species is likely habitat loss or degradation. Assessing the full impact of bush meat harvesting on V. bitatawa requires future investigations.
