Data content © provided by the Oakland Zoo. USA, and other referenced sources listed.
This unusual mid-sized stocky agamid lizard has prominent spines
along its sides and a large, essentially triangle-shaped head.
Forming a sort of shield around the snout is a spiney jaw pouch
which, when swollen, looks like a beard and makes any predator
think twice before attacking. This wide-ranging species shows
considerable geographic variation; its basic color varies from
shades of brown, gray, and reddish-brown to bright orange. The
ventral surface ranges from pale to dark gray, with white elongated
spots edged with black. Mature males have dark "beards" which
become black during courtship and breeding. Adults can grow as
large as ten inches in body length or two feet in total length,
including the tail. Males are larger than females.
II. GEOGRAPHICAL RANGE AND HABITAT:
These lizards are native to Central Australia. They prefer semi-arid
to arid woodland habitats. Time is spent both on the ground and
in trees. They may be found perched on bush branches and even
on fence posts.
Bearded dragons are omnivorous and consume many types of insects,
small vertebrates, and vegetation including fruits and flowers.
IV. LIFE CYCLE/SOCIAL STRUCTURE:
Sexual maturity is reached at one to two years of age. Mature
females typically lay clutches of eleven to sixteen oblong leathery
eggs in early summer. The eggs are laid in nests dug in sandy
soil and the unattended young hatch 3 months later.
V. SPECIAL ADAPTATIONS:
A bulky body and the habit of basking allows them to store heat,
making it possible to operate at lower temperatures than other
lizards. They can also survive higher temperatures for several
hours, since they can regulate body temperature by evaporation.
VI. INTERPRETIVE INFORMATION:
When intimidated, they flatten their bodies and stand erect with
mouth gaping. The light-colored mouth lining, spines bordering
the lower jaw and puffed-out blackish beard give a formidable
appearance. This defensive display has earned these lizards the
common name of "bearded dragon".
Aggressiveness to other members of the group is shown through
"body language". The tip of the tail is slightly curved at the
end and the head is bobbed rapidly. Submission is signaled by
rotating the arms in a full circular motion, which looks a bit
like waving. Ritualistic sparring matches take place in which
both animals are in flat postures, beards and tails up and outward;
they circle each other, biting at one another's tail, but usually
no damage is done.
Their ability to change shades of color, from light to dark, helps
them to regulate body temperature. Color changes can also depend
on emotional state, and may also be used for concealment. When
injured, sick, or dying the back becomes black and the legs pale
Australian desert lizards often make their escape by rising on
their hind legs and running bipedally. They cannot run as fast
as when using four feet, but perhaps this behavior aids in temperature
control. They lift their bodies from the hot ground to lose the
heat they generate in running. This reduces the amount of heat
they take in from the ground and increases the cooling airflow
over their bodies.
- Encyclopedia of Reptiles, Amphibians, and other Cold-Blooded
Animals. Burton, Maurice. 1975. Octopus Books Ltd, PP 160-161.
- "The Inland Bearded Dragon" , The Vivarium, Vol. 4, No. 5.,
- "The Social Life of Bearded Dragons". Zoonooz, June/July, 1995.
San Diego Zoo.