Common basilisks have well-developed eyes and the sexual dimorphism that is found in this and several other Basiliscus species indicates that visual stimuli represent an important means of interspecific communication. The ears of common basilisks (and most other lizards) are also well-developed and serve similar functions to those of the mammalian ear (reception of sound waves, balance, orientation and movement of the head).
Communication Channels: visual
Perception Channels: visual ; tactile ; acoustic ; vibrations ; chemical
Common basilisks are common throughout their range and face no immediate threats to current populations. Continued habitat destruction in tropical regions represents the most significant conservation threat to this species.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
Small female common basilisks grow faster than males of a similar size. Annual and seasonal factors seem to only affect the growth of females. Most females reach sexual maturity around 135 mm of length and males start to produce spermatozoa when they reach lengths of 131 mm.
These lizards do not harm human interests.
Basilisks are popular pets and some people travel to certain areas to see the famous "Jesus Christ Lizard".
Positive Impacts: pet trade ; ecotourism
As generalist omnivores, common basilisks prey on many species. They are also a prey species for a handful of top level predators (see predators). Common basilisks in Panama were found to be hosts for the microbial parasites Plasmodium basilisci and P. achiotense.
Commensal/Parasitic Species:
Common basilisks are omnivorous, though the diet of individuals in Panama indicated a significant preference for animal prey (22% plant material versus 78% animal material). They feed mainly on arthropods, small lizards, snakes, birds, mammals, fishes, freshwater shrimps, and occasionally frogs, but will also feed on flowers and fruits. Juveniles are more insectivorous than adults but will occasionally eat fishes. It has been shown that herbivory increases with age.
Animal Foods: birds; mammals; amphibians; reptiles; fish; insects; terrestrial non-insect arthropods; aquatic crustaceans
Plant Foods: fruit; flowers
Primary Diet: carnivore (Eats terrestrial vertebrates, Piscivore , Insectivore , Eats non-insect arthropods); herbivore (Folivore , Frugivore ); omnivore
Common, or brown, basilisks are found on the Pacific slope of Central and northern South America from southwestern Nicaragua to northwestern Columbia.
Biogeographic Regions: neotropical (Native )
Common basilisks are abundant in Pacific lowland forests of Central America and are the most commonly seen large lizards in western Costa Rica. They inhabit lowland dry, and moist forests, often adjacent to rivers and other waterways. They spend most of their time on the ground but sleep in perches up to 20 meters high at night.
Range elevation: 0 to 600 m.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: forest ; rainforest
Aquatic Biomes: lakes and ponds; rivers and streams
Other Habitat Features: riparian
A captive basilisk lived over 9 years, but few would live this long in the wild. Most males live from 4 to 6 years of age, females most likely have shorter lives on average. Van Devender (1982) found that survivorship of hatchling females is significantly lower than hatchling males. First-year survival for hatchlings can be less than 60 percent. Annual adult survivorship difference may be as much as 60 percent for females and 40 for males, but it is estimated that these counts may have been biased due to greater emigration rates for males.
Range lifespan
Status: wild: 7 (high) years.
Range lifespan
Status: captivity: 9 (high) hours.
Typical lifespan
Status: wild: 2 to 6 years.
Adult common basilisks are large lizards (snout to vent length up to 203 mm) whose tails generally comprise 70 to 75% of total body length (total length to 800 mm). These large tails aid in balance. They are generally brown or olive in color but can range from bright green to olive-brown and bronze. They have darker cross bands and cream to yellow lip and lateral stripes. Juveniles are colored similarly to adults but are generally more vivid and also have three longitudinal stripes on the throat. All age classes have brown to bronze irises. They have long digits with sharp claws for climbing. Males are larger than females and have sail-like crests supported by elongate neural spines including a rounded or pointed head, dorsal, and caudal crest.
Range mass: 200 to 500 g.
Range length: 430 to 800 mm.
Average length: 520 mm.
Other Physical Features: heterothermic
Sexual Dimorphism: male larger; sexes shaped differently; ornamentation
Hatchling iguanids, including common basilisks, are readily eaten by raptors. Lizards such as giant ameivas (Ameiva ameiva) prey on common basilisk eggs, and many mammalian predators undoubtedly eat the eggs as well. Opossums and snakes may prey on adult basilisks while they are sleeping at night. The basilisk's brown or green-olive color probably helps to camouflage the lizard in the branches of trees and shrubs.
Known Predators:
Anti-predator Adaptations: cryptic
Common basilisks begin breeding in March and females lay clutches of eggs over the next ten months. Females reach sexual maturity at around twenty months of age, males sometime in their second year of life. Males display size-related hierarchal dominance in which larger males often attack smaller males and prevent them from breeding. Because of this, many male basilisks do not enter the breeding cycle until 3 or 4 years of age. Male courtship behavior includes head-bobbing, which is typical of many iguanid lizards.
Mating System: polygynous
Breeding begins in March and females may lay several clutches of eggs (numbering 2 to 18 eggs per clutch) throughout the next ten months. Egg-laying is significantly lower in January, February, and March. Larger females lay more eggs than smaller ones.
Breeding interval: Common basilisks begin breeding in March of every year.
Breeding season: Breeding in March, egg-laying in following ten months.
Range number of offspring: 2 to 18.
Range gestation period: 60 to 90 days.
Average age at sexual or reproductive maturity (female): 20 months.
Average age at sexual or reproductive maturity (male): 2 years.
Key Reproductive Features: seasonal breeding ; sexual ; oviparous
A female common basilisk will dig a hole in which to lay her clutch of 2 to 18 eggs. After laying the eggs, she will usually inspect the nest, then fill it with soil using her forelimbs, packing the soil down with her snout. There is no further parental care.
Parental Investment: female parental care ; pre-hatching/birth (Provisioning: Female)
