Choosing a Northern Brown Basilisk
R.D. and Patti Bartlett
The northern brown basilisk is a nervous, fast-moving lizard that can climb well, swim and even run across the surface of calm waters. It is distinctive in appearance and feeds on easily procurable insects, making it attractive as a pet. But its need for large, secure (and quiet) caging makes the basilisk less than ideal for most hobbyists.
Origin and Life Span
The four species of basilisks are members of the neotropical family Corytophanidae. The northern brown basilisk, Basiliscus vittatus, is a native of Mexico southward to Colombia. It was introduced to Florida about 25 years ago and is now commonly encountered along the canals of Dade County. This is the only representative of this family in the United States.
The northern brown basilisks, now available in the American pet trade, are collected from the introduced populations in Florida. There are no commercial captive breeding programs. They live five to ten years in captivity.
The northern brown basilisk is quietly colored but startlingly impressive. In fact, these lizards look unlike any other. They are a sexually dimorphic lizard -- that is, the sexes are different in appearance. Males have a huge head crest, or casque, and attain a total length of more than two feet. The tail is about two thirds of this length. Females are much smaller and the head casque is very much reduced in size. Both sexes are slender and long-legged.
They generally display one or two tones of brown. Males have a weaker body pattern. Females tend to have rather strong banding across the back, a pair of light dorsolateral stripes and a more obscure lateral stripe on each side. Babies lack the crest entirely, but may have a tiny point on the back of their head indicating where the crest will eventually be. They have prominent dorsal banding and strongly contrasting yellowish dorsolateral stripes, and reasonably well defined lateral stripes. Both males and females have a low but easily discernible vertebral crest that extends onto the first third of the tail.
There are no established color variations.
Because of the great surface area of their hind feet, basilisks can run across the surface of quiet waters. If they slow down, they sink and must swim for the rest of the journey. They are also able to climb well and run swiftly on the ground.
How do they behave in captivity? In a word, spastically. This is especially true of wild-collected adults. These lizards will attempt to flee at the slightest disturbance and will quickly batter their nose in their attempts to escape their cage. Even with slow, gentle, overtures, it may take considerable time to begin to win a basilisk's confidence. Babies, and some females, are more approachable than the males. As a group, though, these lizards seldom, if ever, become tame enough to allow handling. They can bite and scratch if carelessly restrained.
Basilisks climb very well, but seldom to any great height. They seem to prefer to ascend tall grasses and rushes rather than trees. They bask in the sunlight for long periods, moving back into the shadows or diving into the water when too hot.
In the wild, basilisks occupy a comparatively huge home territory. In captivity, they should have the largest possible terrarium -- a minimum of 75 gallons for a pair of basilisks.
The terrarium should be equipped with sizable diagonal and horizontal limbs (at least the diameter of the lizard's body) and vining plants to provide the visual barriers and security so important to these lizards when captive.
The terrarium's ambient daytime temperature should be a humid 85 degrees Fahrenheit, but nighttime temperatures can drop by a few degrees. Illuminate and warm one end of the highest perch to 95 to 100 degrees with a full-spectrum UV-B-heat bulb.
The tank should have a substrate that helps maintains high cage humidity. Barely dampened unmilled sphagnum or finely shredded mulch (of some non-aromatic form) will be fine.
These lizards will also enjoy a large but shallow water receptacle. The water temperature should be maintained at about 85 F. This can be accomplished by using an undertank heating pad. The water must be kept fresh and clean.
You can house a male and female or a male and two females, but it is not a good idea to keep two males together. They are territorial and will fight. If they don't fight, they will still engage in mechanisms for defending their territory through body language. They will do push-ups and bob their heads, signals that can mean a great deal to an interloping lizard. One lizard can use them to dominate another to the point that the subordinate becomes severely stressed, even refusing to eat.
Northern brown basilisks are insectivores. In the wild they will eat virtually any type of non-noxious bug that catches their attention. They are agile, and may occasionally leap after passing dragonflies. Occasionally, hibiscus and other blossoms may also be eaten.
Captives will eat roaches, crickets, mealworms, king mealworms, silkworms, pinky mice, minnows and an occasional blossom. You should feed them as much as they will eat in a sitting. Start by placing a handful of crickets in their tank and expect to provide food every couple of days. Feed only healthy, gut-loaded insects.
Growing babies and ovulating females should be given a vitamin/mineral supplement that contains calcium and vitamin D3 supplement twice weekly. Adult males should get the supplement at least once every two weeks. Calcium supplementation is particularly important in preventing metabolic bone disease, or MBD, a serious bone degeneration that happens when a basilisk gets too little of the mineral.
To provide the supplement, you should dust food items with it. Place the feeder insects in a small jar with a pinch or two of the supplement; cover the jar and shake it to coat the insects with the powder. These coated insects are known as "shake and bake" feeders.
Fresh drinking water should always be present in the terrarium. Basilisks will drink from a dish.
Northern brown basilisks depend on fleeing rather than aggression to avoid predators. They have an instinctive, instantaneous flight response that is invaluable to them in the wild -- and makes them a problematic captive. It is especially well developed in wild-collected adult basilisks. They are likely to hide when you just approach their terrarium.
These creatures should be handled little if at all. They will try to flee at the slightest disturbance and will batter their nose as they try to escape their cage. With persistence on your part, a basilisk may eventually climb into the palm of your hand to be fed, but it will never enjoy being grasped or otherwise restrained.
Never grasp your lizard by its tail. Doing so may autotomize the tail, or break it off. Although the tail will regenerate, the new tail is never as neatly scaled or mobile as the original.
Basilisks are nervous lizards that can be difficult to acclimate to captive conditions. Many repeatedly batter and bloody their nose in their attempts to escape.
A broken tail, though unsightly, is usually not a matter of great concern. If this happens on a juvenile specimen, the regeneration will be rapid. It takes longer and is a less perfect regeneration on older lizards.