The Northern Sierra Madre forest monitor (''Varanus bitatawa''), also known by the local names ''bitatawa'', ''baritatawa'', and ''butikaw'', is a large,

arboreal Arboreal locomotion is the Animal locomotion, locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. Th ...

frugivorous A frugivore is an animal that thrives mostly on raw fruits or succulent fruit-like produce of plants such as roots, shoots, nuts and seeds. Approximately 20% of mammalian herbivores eat fruit. Frugivores are highly dependent on the abundance and ...

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...

of the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

'' Varanus''. The lizard is a distinctive food of the

Aeta The Aeta (Ayta ), Agta, or Dumagat, are collective terms for several Filipino indigenous peoples who live in various parts of the island of Luzon in the Philippines. They are considered to be part of the Negrito ethnic groups and share common ...

and Ilongot indigenous people of the Philippines.

Description

The forest monitor lizard can grow to more than in length, but weighs only about . 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. Dorsal ground coloration is black, accentuated with bright golden yellow in life, while the dorsum is golden yellow spots and flecks. News reports emphasized that males have

hemipenes A hemipenis (plural hemipenes) is one of a pair of intromittent organs of male squamates (snakes, lizards and worm lizards). Hemipenes are usually held inverted within the body, and are everted for reproduction via erectile tissue, much like ...

, paired penis-like organs.. However, all male lizards and snakes have hemipenes.

Behavior

''Varanus bitatawa'' is one of only three

lizards in the ''Varanidae'' family along with '' V. olivaceus'' and '' V. mabitang. The Northern Sierra Madre forest monitor specializes in eating the

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...

of Pandan palm trees. 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.

Taxonomy and distribution

''Varanus bitatawa'' was described as a new species in April 2010 by biologists from the

University of Kansas The University of Kansas (KU) is a public research university with its main campus in Lawrence, Kansas, United States, and several satellite campuses, research and educational centers, medical centers, and classes across the state of Kansas. Tw ...

DNA analysis Genetic testing, also known as DNA testing, is used to identify changes in DNA sequence or chromosome structure. Genetic testing can also include measuring the results of genetic changes, such as RNA analysis as an output of gene expression, or ...

has revealed genetic divergence between this species and its closest relative,

Gray's Monitor The Gray's monitor (''Varanus olivaceus'') is a large (180 cm, >9 kg) 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 Gr ...

(''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. The known range of ''Varanus bitatawa'' is currently limited to the Sierra Madre Forest on the northeastern coast of the island of

Luzon Luzon (; ) is the largest and most populous island in the Philippines. Located in the northern portion of the Philippines archipelago, it is the economic and political center of the nation, being home to the country's capital city, Manila, as ...

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

. ''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 suggests that these three species are each others' closest relatives (sometimes referred to as subgenus ''Philippinosaurus''). 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). 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 The Komodo dragon (''Varanus komodoensis''), also known as the Komodo monitor, is a member of the monitor lizard family Varanidae that is endemic to the Indonesian islands of Komodo, Rinca, Flores, and Gili Motang. It is the largest extant ...

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

References

External links

Images of Varanus bitatawa from Reuters

Giant Frugivorous Monitor Lizards in the Philippines
{{Taxonbar, from=Q132394 Fauna of Luzon Reptiles of the Philippines Reptiles described in 2010 Varanus