Ceratophora tennentii

Geographic Range

Ceratophora tennentii , Tennent's Leaf-nosed Lizard, is found only in the Knuckles Hills region of central Sri Lanka, an area characterized by tropical moist montane forest. The range encompasses approximately 175 square kilometers.

• Biogeographic Regions
• oriental oriental
  • native native

• Other Geographic Terms
• island endemic island endemic

Habitat

Ceratophora tennentii is found in the moist tropical montane cloud forests of Sri Lanka's 'wet zone'. This mountainous region exists at an elevation of 700 to 1,200 m above sea level and receives more than 2,000 mm of precipitation each year. The Leaf-nose lizard is an arboreal species found most often on the trunks of mossy trees, but also on low bushes, cardamom plants, and on lianas (Somaweera and Somaweera 2009).

• Habitat Regions
• tropical tropical

• Terrestrial Biomes
• rainforest rainforest

Physical Description

Tennent's Leaf-nosed Lizards are small reptiles named after the conspicuous leaf-shaped projection located at the end of their rostrum. This ornamentation is fleshy, covered in scales and granules, and tipped with a bluntly conical scale. The shape is unique to the species as it is laterally compressed and elliptical from a lateral view. The appendage is present in juveniles and monomorphic in adults, though somewhat smaller in females. The function of this appendage is unknown, however field observations suggest it is not obviously used in breeding or threat display (Pethiyagoda and Manamendra-Arachchi 1998). Some researchers have hypothesized that the appendage serves to increase crypsis by breaking up the lizards' outline (Johnston et al. 2013).

Average snout to vent length is 55-70 mm, and tail length is 130-145 mm (Somaweera and Somaweera 2009). Adults typically have a short and think tongue, a nuchal crest that is poorly defined or lacking completely, and no gular fold. The nostrils are rounded or oval shaped and oriented anterolaterally. The digits and claws are laterally compressed, and the claws are slightly curved and pointed (Pethiyagoda and Manamendra-Arachchi 1998).

Adults are typically reddish brown to olive green on the dorsum and sides (Pethiyagoda and Manamendra-Arachchi 1998). Lateral scales are large, irregular, and often more green (Somaweera and Somaweera 2009). Black markings are found on the area around the eyes and sides of the neck. There are about 10 broad, dark brown bands on the tail with narrow lighter areas in between. The venter is whitish (Pethiyagoda and Manamendra-Arachchi 1998).

• Other Physical Features
• ectothermic ectothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes colored or patterned differently

Development

As with all squamates, fertilization is internal, the male possessing a dual intromittent organ called the hemipenes. This species is oviparous and lays shelled amniotic eggs. Hatchlings resemble the parents, though with much smaller ornamentation.

Reproduction

See "Reproduction."

Tennent's Leaf-nosed Lizards are oviparous, and females lay 2-4 eggs at a time (Somaweera and Somaweera 2009). Males expand a small erectile nuchal crest on the back of the neck while displaying (Hutchins 2003). Little else is known about the reproductive biology of this species.

• Key Reproductive Features
• sexual sexual
• oviparous oviparous

Females provision the eggs (yolk), but probably deposit and then abandon their eggs (as with most agamid lizards) and there is likely no parental care of hatched young.

• Parental Investment
• pre-fertilization
  • provisioning
  • protecting
    • female

Lifespan/Longevity

No data could be found on lifespan and longevity of the Leaf-nosed lizard.

Behavior

Tennent's Leaf-nosed Lizards are slow-moving and arboreal (Johnston et al. 2013). They prefer to spend the majority of their time on low branches of trees utilizing the sit-and-wait predatory strategy (Hutchins 2003). Juveniles are largely terrestrial (Somaweera and Somaweera 2009).

This species is known operate at relatively low body temperatures close to air temperature. Some thermoregulation is managed by basking, often in dappled sunlight. Due to the closed canopy nature of the forest and frequent cloud cover, seeking out open sunlight patches may be too ecologically costly for these organisms (de Silva et al. 2005).

Within the Agamidae family, males are generally known to be territorial and show territorial behaviors more often than females and juveniles. Ceratophora tennentii males have been reported performing two of these territorial behaviors: head bob and body-lift. The head bob behavior is performed by relatively rapid up and down movements of the head and neck only. The body-lift behavior consists of using all four limbs to push the body off the surface immediately followed by descent (Bandara 2012).

Although this species is slow-moving, males may actively attack other rival males. When disturbed, they will occasionally open their mouth wide to display the bright orange lining of their oral cavity (Somaweera and Somaweera 2009).

• Key Behaviors
• arboreal arboreal
• diurnal diurnal
• territorial territorial

Home Range

The home range of this species has not been reported to date.

Communication and Perception

These Leaf-nosed lizards rely mostly on visual communication within the species. Males exhibit territorial behaviors such as a head-bob and body-lift (Bandara 2012). Any use of other senses has not been reported.

When disturbed, members of this species will often open their mouths wide to display the bright orange lining of their oral cavity (Somaweera and Somaweera 2009).

• Communication Channels
• visual visual

Food Habits

Tennent's Leaf-nosed Lizards are sit-and-wait ambush predators that feed on insects, caterpillars, and earthworms (Somaweera and Somaweera 2009). Although they most often feed while in trees, they will occasionally jump to the ground in pursuit of prey (Hutchins 2003).

• Primary Diet
• carnivore carnivore
  • insectivore insectivore
  • eats non-insect arthropods
  • molluscivore molluscivore

• Animal Foods
• insects
• terrestrial non-insect arthropods
• mollusks
• terrestrial worms

Predation

This slow-moving species appears to rely largely on camouflage to evade predators (Hutchins 2003).

• Anti-predator Adaptations
• cryptic cryptic

Ecosystem Roles

Tennent's Leaf-nosed Lizard impacts the ecosystem of the Knuckles range by capturing and consuming insects, caterpillars, earthworms, and other invertebrates (Somaweera and Somaweera 2009).

Economic Importance for Humans: Positive

The Leaf-nosed lizard has no known economic significance to humans, other than acting as a minor predator on insects (Hutchins 2003).

• Positive Impacts
• controls pest population

Economic Importance for Humans: Negative

This species has no harmful impacts on humans.

Conservation Status

Ceratophora tennentii is listed as Endangered on the IUCN Red List. The most prevalent cause of population decrease is destruction of habitat. Approximately five percent of the original extent of Sri Lanka's wet zone rainforest survives and much of this is severely fragmented. C. tennentii is restricted to the Knuckles mountain range, most of which currently has no protection status and is not subject to conservation management (Bahir and Surasinghe 2005). In the 1960s, the vast majority of the remaining forest in the Knuckles Hills was underplanted with cardamom. This process has left the canopy in good condition, but the regeneration of natural forest has been almost completely inhibited (Manamendra-Arachchi and Liyanage 1994).

Other Comments

Three of the five species in the genus Ceratophora display horn-like rostral appendages, however these appendages are radically different from one another. Combined morphological, allometric, and phylogenetic evidence suggests that these horn structures evolved independently three times within the genus (Johnston et al. 2013; Schulte et al. 2002).

Additional Links

Encyclopedia of Life

Contributors

Rachel Emory (author), Michigan State University, James Harding (editor), Michigan State University, Tanya Dewey (editor), University of Michigan-Ann Arbor.

References

Bahir, M., T. Surasinghe. 2005. A Conservation Assessment Of The Sri Lankan Agamidae (Reptilia: Sauria). The Raffles Bulletin of Zoology , 12: 407-412. Accessed November 03, 2013 at http://rmbr.nus.edu.sg/rbz/biblio/s12/s12rbz407-412.pdf .

Bandara, I. 2012. Territorial and site fidelity behavior of Lyriocephalus scutatus (Agamidae: Draconinae) in Sri Lanka. Amphibian and Reptile Conservation , 5(2): 101-113.

Heying, H. 2003. "Agamidae" (On-line). Animal Diversity Web. Accessed November 20, 2013 at http://animaldiversity.ummz.umich.edu/accounts/Agamidae/ .

Hutchins, M. 2003. Leaf-horned agama (Ceratophora tennentii). Pp. 215 in Grizmek's Animal Life Encyclopedia , Vol. 7, 2 Edition. Farmington Hills, Michigan: Gale.

Johnston, G., M. Lee, T. Surasinghe. 2013. Morphology and allometry suggest multiple origins of rostral appendages in Sri Lankan agamid lizards. Journal of Zoology , 289: 1-9.

Manamendra-Arachchi, K., S. Liyanage. 1994. Conservation and distribution of the agamid lizards of Sri Lanka with illustrations of the extant species. Journal of South Asian Natural History , 1 (1): 77-96.

Pethiyagoda, R., K. Manamendra-Arachchi. 1998. A revision of the endemic Sri Lankan agamid lizard genus Ceratophora Gray, 1835, with description of two new species. Journal of South Asian Natural History , 3: 1-50.

Pianka, E., L. Vitt. 2003. Lizards: Windows to the Evolution of Diversity . London, England: University of California Press, Ltd.

Schulte, J., J. Macey, R. Pethiyagoda, A. Larson. 2002. Rostral Horn Evolution among Agamid Lizards of the Genus Ceratophora Endemic to Sri Lanka. Molecular Phylogenetics and Evolution , 22 (1): 111-117.

Somaweera, R., N. Somaweera. 2009. Lizards of Sri Lanka - A Colour Guide with Field Keys . Germany: Andreas S. Brahm.

de Silva, A., R. Meek, A. Bauer, S. Goonewardene, J. Drake, A. Amarakoon, M. Goonasekera. 2005. The first studies on the thermal ecology of Ceratophora tennentii: (Sauria: Agamidae) Inhabiting the cloud forests of Knuckles Massif, Sri Lanka. Lyriocephalus , 6 (1): 65-71.

International Union for Conservation of Nature and Natural Resources. 1996. "Ceratophora tennentii" (On-line). IUCN Red List of Threatened Species. Accessed November 03, 2013 at http://www.iucnredlist.org/details/4178/0 .

Ruchira Somaweera. 2013. "Family Agamidae" (On-line). Sri Lankan Reptiles. Accessed November 03, 2013 at http://www.srilankanreptiles.com/TetrapodReptiles/Agamidae.html .

Wildscreen. 2003. "Tennent’s leaf-nosed lizard (Ceratophora tennentii)" (On-line). www.arkive.org. Accessed November 03, 2013 at http://www.arkive.org/tennents-leaf-nosed-lizard/ceratophora-tennentii/ .