Brown Basilisk

Brown Basilisk, Basiliscus vittatus

Brown Basilisk, Basiliscus vittatus, Male. Photograph taken within the Sian Ka’an Biosphere Reserve, Quintana Roo, March 2021. Photograph and identification courtesy of Marina Sutormina, Stockholm, Sweden.

Brown Basilisk, Basiliscus vittatus, Males. Photograph taken within the Cascada Misol Há, Chiapas, March 2021. Photograph and identification courtesy of Marina Sutormina, Stockholm, Sweden.

The Brown Basilisk, Basiliscus vittatus, is a member of the Corytophanidae family of Basilisk Lizards, a subfamily of the Iguanidae Family. The Corytophanidae family consists of nine members in three genera. There are four global species in the Basiliscus genus. The Brown Basilisk is also known to as the Common Basilisk, Striped Basilisk, and the Yellow-striped Basilisk. Juveniles and smaller species can run up to 20 meters (65 feet) across water, giving them the name  “La Gartija de Jesus Cristo” or Jesus Christ Lizard.

Brown Basilisks are brown or olive brown in color with yellow cross banding on their flanks and dorsal crest. They have a white stripe that extends from their eyes to their rear legs. Their lips and venter are lighter in color and their heads are large. They have a three-part dorsal crest on their head, which is larger in males than in females, that runs dorsally along their back and tail. This species demonstrates sexual dimorphism with males possessing a large flaplike crest that is supported by flexible cartilage and projects from the back of their head to their neck. The females have a folded “hood” outlining the back of their head and lower vertebral crest. Additionally, males have a more elongated snout than the females. They reach a maximum of 61 centimeters (2 feet inches) in total length (including the tail) and are between 200 grams (7 oz) and 600 grams (1 lb 5 oz) in weight.  They are sexually dimorphic with the males being several inches larger than the females, They have large hind feet and long toes with sharp claws. Narrow flaps of skin on the distal edge of each toe allow the Brown Basilisk to move quickly across water. Their tails are long, slender, and laterally compressed.

Brown Basilisks are alert, agile, and can move very quickly to avoid human approach. They have the ability to climb, swim, hop, and run as fast as five feet per second. Adult males are particularly wary and difficult to approach. Brown Basilisks are often arboreal, spending significant time in bushes and the lower branches of trees or thickets, however, they also spend time on the ground. At night they can be found sleeping in vine-covered thickets or in the open on low bushes. They are ambush predators and utilize their speed to consume insects, small lizards, invertebrates, and seasonal berries. They are preyed upon by large reptiles, birds, snakes, and some mammals, and rely on their camouflage, agility, and speed to avoid predation. Female Brown Basilisks lay three to twelve eggs five to eight times during May through August. Their eggs are laid in a secluded, moisture retaining site, usually a hole along a canal bank. The young hatch during the early part of the rainy season from June to September, in about 55 to 65 days. They reach sexual maturity at approximately 9 to 10 cm in length, typically at less than a year of age. During the wet season, it is estimated that hatchlings may reach sexual maturity in as little as three months. No parental care is provided outside of the females selecting a safe nesting site for their eggs. Brown Basilisks have a lifespan of seven to eight years in the wild.

The Brown Basilisk is very similar to the Green Basilisk, Basiliscus plumifrons (a bright green color with black and white markings along the dorsal side of their head and neck). 

The Brown Basilisk is native to southern Mexico, Central America, and northwest Columbia. In Mexico they occur at low and moderate elevations from Jalisco on the Pacific versant, and from northern Taumalipas on the Atlantic versant. Brown Basilisks are found in tropical and subtropical wet, moist, and dry forests in dense vegetation. They typically reside along the margin of most bodies of water.

From a conservation perspective, the Brown Basilisk is considered to be of Least Concern being widespread, common, highly adaptable to habitat alteration, and are able to maintain stable populations. No major threats have been identified for this species. They have also been introduced and established in southern Florida. They are a minor component of the pet trade.