Northern Sierra Madre forest monitor | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Order: | Squamata |
Family: | Varanidae |
Genus: | Varanus |
Subgenus: | Philippinosaurus |
Species: | V. bitatawa |
Binomial name | |
Varanus bitatawa Welton, Siler, Bennett, Diesmos, Duya, Dugay, Rico, Van Weerd, & Brown, 2010 | |
Range of Varanus bitatawa |
The Northern Sierra Madre forest monitor (Varanus bitatawa), also known by the local names bitatawa, baritatawa, and butikaw, is a large, arboreal, frugivorous lizard of the genus Varanus . [2] [3]
The forest monitor lizard can grow to more than 2 m (6 ft 7 in) in length, and weigh up to 15 kg (33 lb), or possibly more. [4] Its scaly body and legs are a blue-black mottled with pale yellow-green dots, while its tail is marked in alternating segments of black and green. [5] Dorsal ground coloration is black, accentuated with bright golden yellow in life, while the dorsum is golden yellow spots and flecks. [2]
News reports emphasized that males have hemipenes, paired penis-like organs. [5] [6] However, all male lizards and snakes have hemipenes. [7]
Varanus bitatawa is one of only three species of frugivorous monitor lizards, along with V. olivaceus and V. mabitang. [2]
The diet of the Northern Sierra Madre forest monitor is reliant on the fruit of Pandan palm trees and Canarium . [8] As a result it is likely an important seed disperser of these plants, but particularly of Canarium, because the consumption of its fruit by monitors of the subgenus Philippinosaurus is an unusual adaptation amongst vertebrates, being able to detoxify the high levels of secondary compounds such as calcium oxalate which otherwise makes digestion difficult. [9]
During June and July, the short fruiting season of Microcos stylocarpa occurs, and their diet then switches to mostly consisting of its sugary berries as opposed to the oilier fruits of Pandan palms and Canarium. [9]
Like V. olivaceus, and unlike V. mabitang, it is not a strict herbivore, supplementing its frugivorous diet with insects and snails. [9]
They spend most of their time in trees, more than 20 meters above the ground; similar species spend less than 20 minutes on the ground per week. [10]
Varanus bitatawa was described as a new species in April 2010 by biologists from the University of Kansas. The holotype specimen was salvaged from a hunter. The specific epithet comes from 'bitatawa', the Aeta name for the species. DNA analysis has revealed genetic divergence between this species and its closest relative, Gray's Monitor (Varanus olivaceus), which is also a fruit-eater, but lives on the southern end of Luzon, rather than the northern end where the forest monitor lizard lives. [2]
The known range of Varanus bitatawa is currently limited to the Sierra Madre Forest on the northeastern coast of the island of Luzon, Philippines.
Varanus bitatawa is most closely related to another species of fruit-eating monitor from the Philippines, V. olivaceus. The relationship of these two species to the third known species of fruit-eating monitor, V. mabitang, is unknown due to a lack of genetic data on V. mabitang, but similar genital morphology [11] suggests that these three species are each others' closest relatives (sometimes referred to as subgenus Philippinosaurus [12] ).
Fruit-eating monitor lizards are most closely related to a larger Indo-Asian clade of small monitor lizards that includes the arboreal V. prasinus complex and the mangrove monitors (V. indicus complex). [12] [13] They are more distantly related to other Indo-Asian monitor lizards, such as V. salvator, and still more distantly related to Indo-Australian monitors, including the well-known Komodo dragon of Indonesia.
Despite being a shy and reclusive species that escaped the notice of biologists until very recently, the species is well known to the indigenous Aeta and Ilongot people who hunt it for food. Both indigenous tribes and the bushmeat market view it as a prized target, making it a heavily hunted species. The Aeta hunt it particularly heavily, preferring it over the marbled water monitor (which is also frequently targeted by the bushmeat market). [14] [2] [15] Although the hunting of wildlife is illegal without a permit in the Philippines under Republic Act No. 9147 9 (with indigenous peoples being exceptions to this rule), the hunting of monitor lizards for personal consumption, the bushmeat market, and the pet trade is widespread and largely uncontrolled. [9]
As it is arboreal and heavily relies on the largest trees in its habitat, it is highly vulnerable to the illegal selective logging that occurs on the already heavily deforested island of Luzon. [2] Selective logging of the dipterocarp forests in which it lives forces it to shelter in smaller trees instead, rending them more visible and more vulnerable to hunting. Furthermore the species cannot be found in areas with regular human activity, such as the proximity of human settlements, making it vulnerable to human encroachment.
An additional problem is the road construction in Northern Sierra Madre Natural Park fragmenting its habitat, and has made this habitat more accessible to loggers, farmers, and hunters. [9]
The first record of this species being illegally captured for sale in the pet trade occurred in 2012, when an 1.7 metre long adult was listed on social media at an asking price of ₱ 100,000 PHP ($2,380 USD). [16]
The Varanidae are a family of lizards in the superfamily Varanoidea and order Anguimorpha. The family, a group of carnivorous and frugivorous lizards, includes the living genus Varanus and a number of extinct genera more closely related to Varanus than to the earless monitor lizard (Lanthanotus). Varanus includes the Komodo dragon, crocodile monitor, savannah monitor, the goannas of Australia and Southeast Asia, and various other species with a similarly distinctive appearance. Their closest living relatives are the earless monitor lizard and Chinese crocodile lizard. The oldest members of the family are known from the Late Cretaceous of Mongolia.
Monitor lizards are lizards in the genus Varanus, the only extant genus in the family Varanidae. They are native to Africa, Asia, and Oceania, and one species is also found in the Americas as an invasive species. About 80 species are recognized.
Parvoscincus is a genus of skinks, lizards in the family Scincidae. The genus is endemic to the Philippines.
Polillo is an island in the northeastern region of the Philippine archipelago. It is the largest island and the namesake of the Polillo Islands. It is separated from Luzon Island by the Polillo Strait and forms the northern side of Lamon Bay.
The Asian water monitor is a large varanid lizard native to South and Southeast Asia. It is widely considered to be the second-largest lizard species, after the Komodo dragon. It is distributed from eastern and northeastern India and Bangladesh, the Andaman and Nicobar Islands, Sri Lanka, through southern China and Hainan Island in the east to mainland Southeast Asia and the islands of Sumatra, Borneo, Java, Lombok, the Riau Archipelago, Sulawesi. It is one of the most widespread monitor lizards.
The black tree monitor or Beccari's monitor is a species of lizard in the family Varanidae. The species is a relatively small member of the family, growing to about 90–120 cm (35–47 in) in total length. V. beccarii is endemic to the Aru Islands off New Guinea, living in an arboreal habitat. The skin color of adults is completely black, to which one common name refers.
The emerald tree monitor or green tree monitor, is a small to medium-sized arboreal monitor lizard. It is known for its unusual coloration, which consists of shades from green to turquoise, topped with dark, transversedorsal banding. This coloration helps camouflage it in its arboreal habitat. Its color also makes the emerald tree monitor highly prized in both the pet trade and zoos alike.
The Gray's monitor is a large monitor lizard known only from lowland dipterocarp forest in southern Luzon, Catanduanes, and Polillo Island, all islands in the Philippines. It is also known as Gray's monitor lizard, butaan, and ornate monitor. It belongs to the subgenus Philippinosaurus. It is largely arboreal and extremely shy. The population of northern Luzon was formerly included in the Gray's monitor, but has been recognized as a separate species, the northern Sierra Madre forest monitor, since 2010.
The cream-breasted fruit dove or cream-bellied fruit dove is a species of bird in the family Columbidae. It is endemic to the Luzon region of the Philippines.Its natural habitat is subtropical or tropical moist lowland to montane forests of up to 1,300 masl. It is threatened by habitat loss, and trapping for the pet trade.
The Panay monitor is an endangered monitor lizard native to Panay Island in the Philippines. Unlike most monitors, it is a specialized frugivore.
The wildlife of the Philippines includes a significant number of endemic plant and animal species. The country's surrounding waters reportedly have the highest level of marine biodiversity in the world. The Philippines is one of the seventeen megadiverse countries and is a global biodiversity hotspot. In 2013, 700 of the country's 52,177 species were listed as threatened.
The turquoise monitor is a species of monitor lizards found in Indonesia. Specifically, it is found on Halmahera Island and in the Maluku Islands.
Dumeril's monitor is a species of lizard in the family Varanidae. The species is endemic to Southeast Asia.
Finsch's monitor is a species of monitor lizard in the family Varanidae. The species is native to New Guinea and Australia.
The marbled water monitor, also known commonly as the Philippine water monitor, is a large species of monitor lizard in the family Varanidae. The species is endemic to the Philippines.
The Quezon Protected Landscape is a protected area in the Republic of the Philippines, spanning the municipalities of Pagbilao, Padre Burgos and Atimonan in Quezon province. The park is situated north of the narrowest section of Luzon in Quezon province, located about 164 km (102 mi) southeast of Metro Manila.
The Sierra Madre is the longest mountain range in the Philippines. Spanning over 540 kilometers (340 mi), it runs from the province of Cagayan down to the province of Quezon, forming a north–south direction on the eastern portion of Luzon, the largest island of the archipelago. It is bordered by the Pacific Ocean to the east, Cagayan Valley to the northwest, Central Luzon to the midwest, and Calabarzon to the southwest. Some communities east of the mountain range, along the coast, are less developed and so remote that they could only be accessed by taking a plane or a boat.
Parvoscincus leucospilos, the white-spotted sphenomorphus, is a species of skink endemic to the Philippines. It is found between 300 and 1,200 m above sea levels in the forests of central and southern Sierra Madre Mountain Range of Luzon Island. This skink hides under rocks or in debris in the banks of streams and rivers. When threatened by predators, such as snakes, it may dive and stay under water for a long time.
Luperosaurus kubli is a species of gecko, a lizard in the family Gekkonidae. The species is endemic to Luzon in the Philippines.
Philippinosaurus is one of the 11 subgenera of the genus Varanus. The group consists of three frugivorous species endemic to the Philippines.