REPTILIA: SQUAMATA: VARANIDAE: Varanus

Varanus yuwonoi Harvey and Barker, 1998

Tricolored monitor

Photos & text by Dr. Robert Sprackland.

Range: Halmahera, Indonesia.

Diagnosis: A large (1+ m/ 3.1 feet) slender monitor with a light face, black or very dark green dorsum (the latter half with many tiny yellow or cream flecks) and a dark tail with light blue bands. The tongue is yellow at the tip, pink behind. There is no black temporal stripe.

Description:  Size large (in excess of 1 m/3.1 ft). Snout acute, slightly depressed at the tip, and slightly convex above the nostrils. Nostrils small, round, and near snout tip. Supraocular scales enlarged, smooth. Eye and ear subequal in size. Tongue pink at tip, pink behind. There is an irregular yellowish streak extending from under the orbit to above the ear. there is no dark temporal stripe.

Limbs strong, pentadactyl and strongly clawed. Adpressed limbs greatly overlap. Longest anterior digit about equal in length to forearm. 

Body slender, covered with small keeled scales. Tail laterally compressed, longer than 1.5 times SVL. Caudal scales do not form annuli, largest scales ventral.

Head yellowish-tan mottled with dark brown. Face with more light markings than top of head. Circumorbital region pale. Body extremely dark green to black, with large dark blotches laterally on the neck. Anterior portion of dorsum unmarked or with few faint lighter spots. From mid body caudad the dorsum is marked with a stellar pattern of many very tiny light cream to yellow flecks. Light and generally unmarked below.

Natural History: Tricolored monitors are active ground-dwelling monitors that forage for food under fallen bark and branches, in mammal holes, and near water. They consume carrion, small mammals, other lizards, and eggs.

Very little is known of the habits and ecology of this species in Indonesia. Halmahera is a major population center, so it is interesting that this species has escaped official notice for so long.  

Reproduction: Egg layers, but specific data are still lacking.

Taxonomy & Relationships: This species shows many affinities with the mangrove monitor lizards (subgenus Euprepiosaurus). 

This striking species was named in honor of Frank Yuwono, the Indonesian animal dealer who collected the type series.

Variation:

Additional Comments: Captives tend to be large, active animals that forage much of the time. They prefer temperatures between 30-40º C (85-104º F), and have a rapid metabolism. Adults need to be fed every 3-4 days. Unlike many monitors, tricolored monitors rarely tend to become tame in captivity. Their active, unpredictable and often aggressive behavior has earned them a nickname, "raptors."

Type Specimen: Texas

 Literature: