Draco jareckii

Excerpt from:

Phylogenetic Systematics, Scaling Relationships, and the Evolution of Gliding Performance in Flying Lizards (Genus Draco)
Copyright by Jimmy Adair McGuire 1998

Draco jareckii Lazell, 1992:488; fig. 9. Type–locality: "Basco, Batan Island, Batanes Province, Philippines" (holotype: PNM 1797).

Diagnosis.—Draco jareckii can be distinguished from all other species of Draco in the Philippines by the following combination of characteristics (color descriptions based on Lazell, 1992):
(1) medium in size (maximum SVL of males = 90 mm [n=24], females = 90 mm [n=12]);
(2) nostrils oriented laterally on snout;
(3) enlarged, thornlike superciliary scale absent;
(4) dorsal scales variable in size, with strong keeling;
(5) tympanum scaled over;
(6) six ribs supporting patagium (contra Lazell, 1992);
(7) lacrimal bone absent;
(8) large black postrictal ocellus surrounding an enlarged white tubercle absent;
(9) dorsal patagial coloration in males mottled gray and brown with irregular concentric bands;
(10) dorsal patagial coloration in females mottled gray and brown with irregular concentric bands;
(11) ventral surface of patagium in males with substantial sooty black pigments on a gray base, diffuse yellow or greenish–yellow pigments also present;
(12) ventral surface of patagium in females with substantial sooty black pigments on a gray base, diffuse yellow or greenish–yellow pigments also present;
(13) males with triangular dewlap, primarily yellow but marbled gray basally, with beige–pink tip;
(14) gray–brown dorsal body coloration in both sexes;
(15) orbital region of males not heavily suffused with dark pigments.

Draco jareckii can be distinguished from all other species of Draco on the basis of its unique dorsal patagial color pattern (see below). Draco jareckii can be further distinguished from D. bimaculatus, D. cyanopterus, D. guentheri, D. palawanensis, and D. reticulatus on the basis of its scaled over (versus unscaled) tympana. It can be further distinguished from D. bimaculatus and D. mindanensis based on the number of ribs supporting its patagia (six versus five). It can be further distinguished from D. mindanensis based on the orientation of its nostrils (oriented laterally versus posterodorsally) and the absence (versus presence) of a lacrimal bone. It can be further distinguished from D. cyanopterus, D. guentheri, and D. reticulatus based on the absence (versus presence) of an enlarged, thornlike superciliary scale. It can be further distinguished from D. bimaculatus, D. cyanopterus, D. guentheri, D. mindanensis, D. ornatus, D. reticulatus, and some populations of D. spilopterus based on the presence of a primarily yellow dewlap in males (versus white, orange, green, or brown).

Description.—A medium–sized species, maximum observed SVL in males = 90 mm, females = 90 mm (Lazell, 1992); dorsal head scales small to medium–sized, heterogeneous, variably keeled or rugose; rostral 2–3 times wider than high, bordered by 4–6 postrostrals; internasals, frontonasals, and prefrontals small excepting a series of enlarged, strongly keeled scales arranged in shape of inverted "Y", the base originates a few scales posterior to rostral, arms contact supraorbitals; supraoculars granular laterally, grading to much larger size medially such that medialmost supraoculars larger than all surrounding cephalic scales; frontoparietals and parietals equal in size or 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, excepting 1–2 enlarged, keeled scales, similar in structure to anterior superciliaries, wider than high, not laterally compressed and thornlike; loreals and lorilabials immediately superior to supralabials relatively large, remaining loreals and lorilabials much smaller, but substantially larger than adjacent palpebrals; an enlarged scale, wider than tall usually present immediately superior to posteriormost supralabial; one to several pre–, sub–, and postoculars sometimes enlarged forming continuous or discontinuous subocular series, remaining postoculars small; a series of 3–4 large keeled scales extending posteriorly from posterior border of orbit; supralabials 8–12, anterior border convex, posterior border concave, 1–3 times longer than tall, anteriormost supralabial usually smaller than others, posteriormost supralabial usually longest; infralabials 8–11, pentagonal or rectangular; tympanum covered with scales, 1–2 enlarged scales present centrally; tympanum surrounded by granular scales, a large tubercle present a few scales anterior to tympanum; scales surrounding corner of mouth granular; remaining temporals, occipitals, and nuchals granular except for 1–2 tubercles superior to tympanum midway between tympanum and nuchal crest and one, 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 much enlarged distally; dewlap scales of males enlarged at distal extremity.

Dorsal body scales imbricate, variably keeled; a midvertebral nuchal crest composed of laterally compressed dorsal scales present, comprised of 17–25 scales in males, 17–18 scales in females; lateral nuchal crests present in both sexes; middorsals 2–4 times larger than scales of lower flanks, a discontinuous series of much enlarged, keeled scales present along flanks near proximal edge of patagia extending from lateral nuchal crests, along base of patagium, to sacral region; conspicuously enlarged series of keeled paravertebral scales present; caudals strongly keeled; paired, enlarged middorsal caudals extending length of tail; paired, enlarged, subcaudals extending length of tail; over proximal 10% of tail, lateral caudals strongly keeled forming weak fringe; dorsal patagium with juxtaposed scales, variably keeled, keels arranged into linear series that extend parallel to axis of body; ventral patagium with flat, delicate scales, variably keeled; ventral body scales strongly keeled, slightly smaller than dorsals in size; brachials imbricate, variable in size and degree of keeling; prebrachials about equal to largest dorsals in size, strongly keeled, grading smoothly into slightly smaller keeled suprabrachials; postbrachials much smaller than other brachials, weakly keeled or unkeeled; infrabrachials weakly keeled, approximately equal to postbrachials in size, much smaller than suprabrachials; antebrachials slightly larger than brachials, variably keeled, juxtaposed or weakly imbricate; infra–antebrachials smaller than other antebrachials; infracarpals very small, keeled or mucronate, proximal subdigital lamellae with 2–4 keels, distal subdigital lamellae with 1 keel; femorals highly variable in size and degree of keeling; prefemorals, anterior suprafemorals larger than dorsals, strongly keeled; posterior suprafemorals granular, unkeeled; postfemorals granular, variably keeled, keels directed posteriorly rather than distally; infrafemorals much smaller than ventrals in size, keeled; a series of enlarged, flaplike posterior infrafemorals forms conspicuous fringe along posterior edge of upper hind limb, continuing along posterior edge of proximal half of lower hind limb; tibials keeled, smallest proximally and distally, equal to dorsals in size elsewhere, pretibials largest; tarsals strongly keeled or mucronate, infratarsals much smaller than supratarsals, proximal subdigital lamellae with 2–4 keels, distal subdigital lamellae with 1 keel, 27–33 subdigital lamellae on fourth toe. Patagia supported by 6 ribs (eight of eight); pleurodont teeth usually 7 (five of eight), sometimes 6 (three of eight); lacrimal bone absent.

Coloration in life.—Detailed descriptions of the color pattern of Draco jareckii in life were provided by Lazell (1992). Lazell (1992) described the dorsal body coloration of the holotype (male) as "dull fawn brown on the head and anterior trunk...broken by sooty to slate–gray brown tones, especially posteriorly. On mid–trunk and tail, brown gives way to shades of lead to ashy gray with a greenish tint posteriorly. Laterally the head was patterned in ash–gray and warm brown, shading to yellowish on the upper eyelid." The dewlap was described as "lemon yellow with a beige–pink tip and gray marbling basally" and the ventral surfaces of the throat lappets were described as "pale yellowish–gray with dark gray mottling." The dorsal patagial coloration was "mottled in shades of ash to slate–gray, with brown tones postero–basally, in irregularly concentric zones" and the ventral patagial coloration was said to be similar to that of the dorsal patagium, "but of a more contrasting ash and soot" in a "roughly concentric pattern". A yellow suffusion was evident between the posterior ribs. Lazell (1992) described the female color pattern as darker than that of males with more gray and less brown tones. Females tended to show more "golden–yellow tints" on the head, trunk, and limbs. The much smaller dewlap was described as "pale yellow with sooty spots" and the ventral surfaces of the throat lappets were yellow. The dorsal patagial coloration was also described as darker than that of males and of a different pattern. In females, "a slatey to sooty intercostate pattern contained bold, near–white and gray–greenish blotches. There were prominent light, ash to lead gray radials" and a "brown tinge postero–basally." The ventral patagia of females was described as "more boldly marked than in males, approaching black and white with a considerable yellow or yellowish–green postero–basal wash."

Distribution.—Draco jareckii is known only from Batan Island, although other islands in the immediate vicinity, including two (Sabtang and Ibuhos) that are part of the same island bank, have not been surveyed (Figure 1.5).

Natural History.—Virtually nothing is published on the natural history of Draco jareckii. Lazell (1992) noted that the species occurs both in forest and in relatively denuded areas with sparse trees and tends to perch head downward (very unusual for Draco) on the trunks of these trees at a height of 1.5 to 6 meters.