Draco dussumieri Duméril & Bibron, 1837

Common Name and Base Coloration

This species, commonly called the southern flying lizard, has a brown base color marked with grey patches that match tree bark patterns, and can change its color to a limited extent.

Size Measurements

Adult southern flying lizards reach a total length of about 23 cm (9.1 in), with a snout-to-vent length (SVL) of 7–9 cm (2.8–3.5 in) and a tail length of 10–13 cm (3.9–5.1 in).

Head Morphology

The lizard has a rounded head with a short snout, and its nostrils point upwards.

Activity Pattern

It is active during the day, after warming up in the early morning sun.

Sexual Dimorphism (Dewlap)

Males have a long yellow dewlap, which is shorter in females.

Foraging and Gliding Behavior

The lizard climbs tree trunks to search for insect prey, and leaps from tree tops to glide to adjacent trees.

Patagium Structure

It glides by extending its patagia, which are flaps of skin on both sides of the body supported by six elongated ribs, with specialized musculature to extend them outward.

Modified Breast Muscles

Its breast muscles are also modified to support more efficient breathing and its active lifestyle.

Glide Control Structures

The sides of the neck are stretched to form a pair of smaller "wings" around the head, and the lizard uses its tail to control glide direction.

Patagium Underside Markings

The underside of the patagium is patterned with black blotches over yellow and purple; these patterns vary individually, and the unique markings are used to identify individual lizards and estimate population sizes.

Ocular Tubercle

A prominent horn-like conical tubercle sits behind and above the posterior part of the eye.

Male Secondary Sexual Traits

Males have a small crest on the nape, and a long narrow yellow gular sac on the throat that is longer in males.

Dorsal and Throat Texture

The lizard's back is rough, and its throat has irregular brown spots.

Head Wing Structure

In addition to the patagia, the hyoid apparatus (a structure associated with the tongue) expands throat lappets horizontally to create the small wing-like structures that support the sides of the head.

Primary Distribution Range

Draco dussumieri is primarily found along the Western Ghats and associated hill forests of Karnataka, Kerala, Tamil Nadu, Goa, and Maharashtra in southern India.

Eastern Ghats Records

It has also been reported from parts of the Eastern Ghats (Talakona) in Andhra Pradesh.

Historical Distribution Observation

Nelson Annandale recorded the species as "common about ten miles north of Trivandrum, but apparently very local."

Modified Habitat Use

It is often found in coconut and betel-nut plantations located near forests.

General Diet and Activity Traits

The southern flying lizard feeds exclusively on insects, and is strictly diurnal, sleeping on flat surfaces at night.

Regional Diet Preference

Specimens collected from northern Karnataka were found to feed heavily on weaver ants (Oecophylla smaragdina).

Breeding Display Period

In Kerala, males display actively from February to April, mostly in the forenoon after warming up in the sun.

Male Courtship Initial Behavior

Males maintain small territories; when they detect a nearby female, they bob their head and extend their gular pouch.

Pre-Gliding Color Change

Before gliding toward the female, males can change their skin color to silvery grey to become more conspicuous.

Glide Initiation Mechanism

They leap using their hind legs, with specialized adapted musculature at the base of the tail, before spreading the patagium.

Glide Landing Process

During gliding, the forelimbs are attached to the patagium, and are released just before landing.

Seasonal Daily Activity Pattern

During the hot midday in summer, the lizard rests in the cooler canopy and becomes active again in the late afternoon.

Cool Weather Basking Behavior

During cooler weather, it basks in the sun.

Courtship Behavior

Males chase females and court them with ritualized movements.

Copulation Behavior

During copulation, the male mounts the female and bites her nape.

Male Rival Display

To intimidate rival intruding males, males expand and fold their patagium and make conspicuous movements.

Arboreal Lifestyle

The southern flying lizard is almost entirely arboreal.

Female Nesting Behavior

Females descend to the ground to lay eggs in soil during the monsoon.

Clutch and Incubation Details

Females lay a clutch of about four eggs, which hatch after around fifty days.

Lowland Population Density

A population estimate conducted in an areca plantation in the Western Ghats found a population density of about 13 lizards per hectare.

High Altitude Population Density

At the higher altitude site of Valparai, population density was much lower, at less than 2 lizards per hectare.

General Predators

The southern flying lizard has many predators, including arboreal snakes and birds.

Avian Predator Species

Two bird species observed preying on this lizard are the Indian golden oriole and the black-capped kingfisher.

Mammalian Predator Species

Lion-tailed macaques have also been recorded feeding on southern flying lizards.