Draco bimaculatus
Excerpt from:
Phylogenetic Systematics, Scaling Relationships, and the Evolution of Gliding Performance in Flying Lizards (Genus Draco)
Copyright by Jimmy Adair McGuire 1998
Draco bimaculatus Günther, 1864:127. Type–locality: "Philippine Islands" (holotype: BM 24.1.g).
Draco lineatus De Witte, 1933:2.
Draco lineatus bimaculatus Hennig, 1936:197; fig. 11c.
Diagnosis.—Draco bimaculatus can be distinguished from all other species of Draco in the Philippines by the following combination of characteristics:
(1) small adult size (maximum SVL of males = 70 mm [n=36], females = 71 mm [n=35]);
(2)nostrils oriented laterally on the snout;
(3) enlarged superciliary tubercle absent;
(4) dorsal scales uniform in size and without keeling;
(5) tympana unscaled;
(6) five ribs supporting patagium;
(7) lacrimal bone absent;
(8) large black postrictal ocellus surrounding an enlarged white tubercle present;
(9) dorsal patagial coloration in males a lichenate blend of green, yellow, and dark brown;
(10) dorsal patagial coloration in females a lichenate blend of green, yellow, and dark brown;
(11) the ventral surface of male patagium blue with extensive black spotting;
(12) ventral surface of female patagium yellow with extensive black spotting;
(13) males with a small rounded dewlap off–white in coloration;
(14) pale brown or tan dorsal body coloration in both sexes, with flecks of green, white, and black scattered throughout;
(15) orbital region of males not heavily suffused with dark pigments.
Description.—A small species, maximum observed SVL in males = 70 mm, females = 71 mm; dorsal head scales small, heterogeneous, variably keeled or rugose; rostral 1.2–3 times wider than high, bordered by 3–7 postrostrals; internasals, frontonasals, and prefrontals small except for 2–3 larger keeled scales that form lineate ridge down middle of snout parallel to long axis of body; supraoculars granular laterally, grading to much larger size medially such that medialmost supraoculars larger than all surrounding cephalic scales; frontoparietals and parietals slightly larger than scales of snout; interparietal slightly larger than surrounding parietals, always with opalescent lens; nasals turret–like, pierced centrally by external nares, nares point laterally and slightly dorsally; 3–4 canthals, strongly keeled; anterior superciliaries elongate, keeled; posterior superciliaries granular, a slightly larger keeled scale sometimes present, no enlarged, thornlike superciliary scale; loreals and lorilabials immediately superior to supralabials relatively large, remaining loreals and lorilabials much smaller, granular, juxtaposed, only slightly larger than adjacent palpebrals; an enlarged scale, usually wider than tall, usually present immediately superior to posteriormost supralabial; a large tubercle occasionally present superior and slightly posterior to corner of mouth; a few pre–, sub–, and postoculars sometimes enlarged forming a discontinuous series, remaining postoculars granular; a series of 2–3 large scales extend posteriorly from posterior border of orbit; supralabials 7–11, pentagonal, 1–3 times longer than tall, anteriormost supralabial usually much smaller than others, posteriormost supralabial usually much longer than others; infralabials 7–11, pentagonal; tympanum unscaled, surrounded by granular scales, a large tubercle present a few scales anterior to tympanum; scales surrounding corner of mouth granular except for enlarged, white tubercle approximately 3–5 scales posterior to corner of mouth; remaining temporals, occipitals, and nuchals granular except for 1–2 tubercles superior to tympanum midway between tympanum and nuchal crest and a third, larger tubercle posterior and slightly superior to tympanum immediately posterior to underlying quadrate bone; mental bordered by 3–5 postmentals; gular scales and scales of dewlap and ventral surfaces of throat lappets granular, scales of dorsal surfaces of throat lappets slightly enlarged distally.
Coloration in life.—The coloration of males and females is very similar, although subtle differences exist in the patagial coloration and more extreme differences are present in the coloration of the dewlap and throat lappets. The dorsum is pale brown or tan with flecks of green, white, and black scattered throughout. There are five pairs of enlarged presacral melanic blotches or chevrons that are arranged paravertebrally; the melanic blotches continue postsacrally for a short distance before grading into caudal banding. Smaller melanic spots may be present between the larger blotches. The five enlarged paravertebral blotches may be accompanied by complementary lateral blotches that continue as radially arranged bands on the patagium. The limbs are mottled with tan and brown proximally, with dark brown banding becoming increasingly distinct distally; the manus, pes, and digits with discrete brown bands. A pair of black patches posterior to the parietals may form an indistinct nuchal "loop" that extends from eye to eye. A large melanic interorbital spot is present in both sexes and a nuchal spot is present in females, but absent from males. A large melanic ocellus enclosing a conspicuous white central tubercle is present at the corner of the mouth. The orbits are not suffused with dark pigments. The ventral body coloration is greenish–white and brown spotting may be present over the pectoral region. In females, the coloration of the dewlap and ventral surfaces of the throat lappets is a vivid combination of black and white (usually tinged with ultramarine blue). The dewlap is mostly black, but the leading edge (that portion immediately overlying the second ceratobranchial elements of the hyoid apparatus) is bright white or aqua. There is also a prominent white or aqua crossband that extends between the distal edges of the throat lappets, bisecting the black gular coloration and giving the throat a banded appearance. This crossband is continuous with the white leading edge of the dewlap. An additional white band may also form the anterior border of the black gular area and an indistinct white blotch usually extends posteriorly from the leading edge of the dewlap into the center of the otherwise black dewlap. In males, the underlying pattern of the dewlap and throat lappets is similar to that of females (see below), but most of the coloration is absent, leaving only a pale tan or buffy remnant with scattered, indistinct, black central smudging. The coloration on the dorsal surface of the patagium is a lichenate blend of green and black and may or may not include a yellow component. The patagium is also covered with many white or pale yellow lines or striations that are oriented parallel with the body. The ventral surface of the patagium is covered with large melanic blotches in all D. bimaculatus, but the base coloration differs between the sexes. In males, the ventral patagium has a deep blue cast, whereas the ventral patagium is pale yellow in females.
Distribution.—Draco bimaculatus is known from the islands of Mindanao, Leyte, Samar, Bohol, Ponson, Basilan, Dinagat, Siargao, Tawitawi, Jolo, Sanga Sanga, and Lapac (Figure 1.2). These islands correspond to the Mindanao and Sulu Archipelago faunal complexes of Heaney (1986).
Natural History.—Draco bimaculatus appears to be a species of primary and secondary forest habitats, as well as of coconut groves immediately adjacent to forest habitats. Open coconut plantations far removed from forest (possibly more than just a few hundred meters) appear not to be inhabited by this species. Draco bimaculatus occurs in sympatry with D. ornatus on Samar, with D. reticulatus and D. ornatus on Bohol, and with D. everetti, D. guentheri, and D. mindanensis on Mindanao. As appears to be the case with all species of Draco in the Philippines, D. bimaculatus appears to feed primarily on ants.
Range Map:
