Calumma nasutum

The Calumma nasutum, commonly known as the Madagascar pimple-nose chameleon or big-nosed chameleon, is a small species of chameleon endemic to the island of Madagascar. Its taxonomic identity is currently under revision, with indications that it may represent a complex of several distinct species. This species is characterized by its small size and a notable soft dermal appendage on the front of its nose, a feature shared within its species group.

Physical Characteristics

This arboreal chameleon typically reaches a total body length of about 11 cm. Its most distinguishing feature is a prominent, paddle-like appendage protruding from the nasal region. This appendage is thought to be larger and more square-shaped in males, serving as a means of identifying potential mates. Males also often possess a more noticeable casque, or bony head crest. Both sexes generally display dull coloration, ranging from grey, brown, tan, or light green, frequently marked with dark vertical crossbars along their flanks. Some individuals may exhibit a white lateral band, and legs can be greenish. Other characteristic features include a prehensile tail, fused toes, and independently mobile, turret-like eyes, all adapted for an arboreal lifestyle. The snout is sharply pointed, and the body is covered in smooth hair.

Habitat and Behavior

The Calumma nasutum inhabits primary forests, secondary forests, and forest edges in Madagascar. It is typically found in low vegetation, preferring thin trees, shrubs, bushes, and dense lianas within rainforest environments, generally one to two meters above the ground. They are rarely encountered in open terrain, favoring dense foliage. This species is predominantly nocturnal, with foraging and mating activities occurring at night. It catches prey, such as small invertebrates like spiders, crickets, and roaches, using its remarkably long tongue. The chameleon employs a sit-and-wait ambush strategy. A significant defense mechanism is its ability to change color, allowing it to blend seamlessly with its surroundings. Behaviorally, they are solitary and move cautiously along slender branches and twigs, using their fused toes for grip and their prehensile tail as an additional anchor. When resting or sleeping, they are observed to position themselves head downwards, clinging to a narrow twig or vine.

Reproduction and Lifespan

Calumma nasutum reproduces sexually. Females kept in captivity have been observed to lay multiple clutches of eggs annually, with each clutch typically containing two to six eggs. These eggs require an incubation period of approximately 90 days at a temperature around 23 degrees Celsius. A healthy individual not facing threats from predation or habitat destruction can expect a lifespan of 5 to 7 years.

Conservation Concerns

The species is listed in Appendix II of CITES, necessitating close monitoring of any international trade. While specific conservation measures exclusively for the Calumma nasutum are not extensively documented, broader efforts are underway to preserve Madagascar's biodiversity. Significant threats include the destruction and loss of humid forests, largely due to slash-and-burn agriculture and resulting fires. Habitat degradation caused by invasive species, climate change, and deforestation also impacts the species, potentially leading to localized population declines, particularly in areas where densities are already low.