What Do Basilisk Lizards Eat?

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What do basilisk lizards eat in the wild?

Field research on the common basilisk (Basiliscus basiliscus) in Panama found a diet that was 78 percent animal material. Plant matter made up only 22 percent of what these lizards actually ate. That makes the genus mostly carnivorous, not omnivorous, for most of its life.

The animal side of the menu is broad. Researchers recorded arthropods, small lizards, snakes and birds. They also found small mammals, fish, freshwater shrimp and frogs taken near water.

The plant side stays narrow. It is mostly flowers and fruit picked up while foraging along riverbanks.

Juveniles lean harder into insects than adults do. Herbivory increases with age. A young basilisk is essentially an insectivore.

A large adult male adds more plant matter and bigger prey as it grows.

Diet by species: common, brown and green basilisks

Basilisk lizard food varies a little by species, mostly because of body size and habitat. The brown or striped basilisk (Basiliscus vittatus) is smaller and stays closer to insects and fruit its whole life.

The larger common basilisk takes more vertebrate prey once it reaches adult size.

The green or plumed basilisk is the species most often kept as a pet. Zoo diet records for this species list insects, spiders and smaller lizards.

Small mammals, crayfish and snails round out the natural menu. Captive collections usually simplify that down to insects and earthworms as the daily staple.

What to feed a pet basilisk lizard

The safest way to answer what do basilisk lizards eat as pets is to mirror that wild ratio. Build the diet around a rotating variety of feeder insects. Then add a small amount of produce once the lizard is closer to adult size.

No single feeder insect covers every nutrient a basilisk needs. Variety matters more than any one species of bug.

• Crickets, dubia roaches and discoid roaches as everyday staples
• Silkworms, hornworms and phoenix worms in rotation for variety and moisture
• Mealworms and superworms now and then, since the harder shell takes more digesting
• Waxworms as an occasional treat only, since they run high in fat
• Earthworms, which zoo diet sheets list alongside insects as a captive staple

Every feeder insect should be gut loaded on a high calcium diet first. The Merck Veterinary Manual recommends three days on that diet before the insect goes into the enclosure, with 24 to 48 hours as the practical minimum.

A gut loaded insect passes more calcium, vitamin A and moisture on to the lizard. A bug pulled straight from a cricket tub cannot match that. Our feeder insect guide covers the full list of safe options.

Prey size matters as much as prey type. Keep each insect no wider than the space between the basilisk’s eyes. Anything larger raises the risk of regurgitation or impaction.

Basilisk lizard feeding schedule

A basilisk lizard feeding schedule should shift with age. The Merck Veterinary Manual puts insectivorous and omnivorous lizards on daily feeding for juveniles and small species, and every other day otherwise. The Smithsonian National Zoo lists 18 to 24 months as the age of maturity for the green crested basilisk, which is the point to settle onto the adult schedule.

Watch body condition, not just the calendar. A basilisk with a thick tail base and no visible hip bones is eating enough. A lizard that looks thin along the spine or tail needs food more often, or larger portions.

For general lizard feeding basics beyond this species, see our guide to what lizards eat.

Calcium and vitamin supplementation

Supplementation is not optional for a captive basilisk. Merck puts the natural calcium content of feeder insects at 0.03 to 0.3 percent against 0.8 to 0.9 percent phosphorus, the reverse of what a lizard needs. Its target for the finished diet is a calcium to phosphorus ratio of at least 1.2 to 1.

Merck’s fix is a gut loading diet with 12 percent calcium carbonate, fed to the insects for three days. Dusting is the second tool: coat feeder insects with a calcium powder before most feedings, and put a separate multivitamin powder on a less frequent schedule.

Basilisks kept without direct UVB exposure need a calcium powder that includes vitamin D3. A calcium powder with added D3 covers that need. Lizards housed under quality UVB lighting can generally use a plain calcium powder instead.

A separate reptile multivitamin and mineral powder once or twice a week fills the rest of the gap. It covers vitamin A, vitamin E and trace minerals that calcium powder alone does not provide.

Skip vitamin dusting on the same day as calcium dusting. Overlapping the two supplements too often can push some fat soluble vitamins toward excess.

Fruits, vegetables and treats for adult basilisks

Wild data shows plant matter rising with age. It goes from a minor share of the diet in juveniles to a real but still secondary share in adults.

Pet basilisks can follow the same pattern. Skip produce almost entirely for young, growing lizards, then introduce it gradually once the lizard nears adult size.

Soft, low oxalate fruit such as papaya, mango, banana and berries works well. Offer it in small, finely chopped pieces once or twice a week.

Leafy greens like collard greens, dandelion greens and mustard greens can be offered the same way. Chop them small enough for the lizard to manage.

Treat produce as a minority ingredient, not a meal replacement. Insects should still make up most of an adult basilisk’s calories. That matches the roughly 80 percent animal, 20 percent plant split researchers recorded in the wild.

Water and hydration

Water is central to basilisk behavior, as our basilisk habitat guide covers in more depth.

Basilisks stay close to water in the wild. They sleep on branches over rivers and streams and drop in to escape predators. That same water association carries over to feeding and hydration in captivity.

A large, secure water dish the lizard can enter keeps a basilisk hydrated between meals. Regular misting of the enclosure adds to that.

Moisture rich feeder insects like silkworms and hornworms add to that hydration. So does drinking directly from standing water or droplets on leaves.

Feeding mistakes to avoid

A handful of feeding mistakes come up again and again with pet basilisks. Most are easy to avoid once a keeper knows to look for them.

• Feeding insect prey that is too large, which raises the risk of regurgitation or impaction
• Skipping gut loading, which leaves feeder insects nutritionally thin no matter how often they are dusted
• Relying on one or two feeder species long term instead of rotating several
• Dusting with both calcium and multivitamin powder on the same feeding, most days of the week
• Offering wild caught insects, which can carry pesticides or parasites
• Leaving live insects loose in the enclosure overnight, where crickets and roaches can bite a resting lizard

A shallow, escape resistant feeder dish keeps insects contained at feeding time. It also cuts down on loose bugs biting the lizard while it sleeps.

Some basilisks are reluctant to chase insects around a large planted enclosure. Offering food with a pair of feeding tongs can help a nervous or newly acquired lizard start eating reliably.

Frequently Asked Questions

Do basilisk lizards eat fruit?

Adult basilisks eat small amounts of soft fruit. Wild diet studies put plant material at only about 22 percent of total intake for the common basilisk. Juveniles eat almost no fruit at all, favoring insects instead.

How often should I feed my basilisk lizard?

Juveniles under about six months old eat once a day, which matches the Merck guideline for young insectivorous lizards. Most adults do well on food every other day. Body condition, not a fixed calendar, is the best guide to whether the schedule needs to change.

Can basilisk lizards eat mealworms?

Mealworms can be offered now and then. Their harder shell makes them tougher to digest than softer bodied feeders like crickets or silkworms. They work best as one item in a rotation rather than a daily staple.

Do basilisk lizards eat other lizards?

Wild diet data for the common basilisk lists smaller lizards among the prey items adults eat. Snakes, birds and small mammals round out that list.

That level of predation is not something to replicate at home. The captive diet should stay built around feeder insects.

Do basilisk lizards need live food?

Live, gut loaded insects are the foundation of a basilisk’s diet, since the species evolved to hunt moving prey. Zoo diet sheets for green basilisks list live insects and earthworms as the standard captive menu.

How much should I feed a baby basilisk lizard?

A young basilisk generally eats as many appropriate sized insects as it will take in about 10 to 15 minutes. Offer that meal once a day. Insects offered to a hatchling should be sized to roughly the width between its eyes or smaller.