In Living Color

This monitor lizard can grow to more than six feet and 6 inches – more than the height of the average human. They have scaly bodies and are blue-black mottled with pale yellow-green dots, while their tails are marked in alternating segments of black and green, according to a 2010 article in the Herald Sun. The dorsal side appears black, accentuated with bright golden yellow spots and flecks.

The color of this monitor does not appear to fade with age.

Newly-discovered Lizard

Although western scientists “discovered” the Northern Sierra Madre forest monitor (Varanus bitatawa) only recently, the species was already well known to local indigenous people living in and around Casiguran, Aurora, reported Jonathan Mayuga in a 2018 Business Mirror article.

The indigenous Isnag of Apayao even have a local name for the tree-dwelling Varanus bitatawa: lopi, different from the local name of the common monitor lizard or bayawak commonly found on the ground, which they call banyas. This indicates that the species, which is a distinctive food of the Aeta and Ilongot indigenous people of the Philippines as reported by Susan Milius in a 2010 Science News report, have been thriving in Northern Cordillera all this time.

A close relative of the Komodo dragon (Varanus komodoensis), the unique forest monitor was formally described as a new species in 2010. They are known by the local names bitatawa, baritatawa, and butikaw.

Forest Obligate

The Sierra Madre mountain range is the longest mountain range in the Philippines, which runs in a north-south direction from Cagayan to the north and Quezon to the south. Until recently, V. bitatawa was thought to be restricted to the Sierra Madre range, particularly within the provinces of Cagayan, Isabela, and Aurora.

This is because the elusive forest monitor lizard is a frugivore, which means they are fruit-eating lizards, and need large forest areas to ensure their survival. V. bitatawa is one of only three frugivorous lizards in the Varanidae family, along with V. olivaceous and V. mabitang.

This lizard is said to consume the fruit of Pandan palm trees. They spend most of their time in trees more than 20 meters above the ground. Like all male lizards and snakes, the males of this species have hemipenes, which are paired penis-like organs.

Recently, however, experts studying the iconic Philippine eagle under the Philippine Eagle Foundation might have come across an entire population in Apayao.

New Discovered Habitat

A Philippine eagle was tracked in Northern Cordillera carrying home a carcass of a bitatawa, according to a June 2018 article by Tatiana Abano-Sarigumba, Jayson Ibanez, Rafe M. Brown and Luke J. Welton in the Herpetological Review. The lizard’s remains were discovered inside the nest of a Philippine eagle in Apayao, less than 100 kilometers from the Northern Sierra Madre mountain ranges, the only place where the monitor is known to exist.

The discovery of both the Philippine eagle and the bitatawa, both forest specialists, in the Cordillera mountain range indicates that the forest ecosystem in this area is thriving and is able to support both species. Biodiversity conservation may be more effective if it moved away from isolated pockets of study and involved coordination between different protected areas, such as the Cordilleras and the Sierra Madres.

This appeared in Animal Scene magazine’s November 2018 issue.