
Basilisk Lizard, Costa Rica
Gliding on a pontoon boat down the Tarcoles River in Costa Rica, we were literally focusing on birds when a unique lizard completely surprised us. I had never seen this phenomenon before, and I have never seen it since.
The lizard, the common basilisk, lives in the rainforests of Central and South America near rivers and streams.

Tarcoles River, cattle egret
Earlier, we had been hiking and birding the jungle of Carara National Park. The heat was extreme, humidity was high, and the mosquitoes were thick.
By late afternoon the earth had cooled down, wildlife were out, and we were quietly and slowly cruising through the mangrove swamp. The slight breeze produced by the boat was heavenly.

Boat-billed Heron
We came across nesting boat-billed herons, and a bountiful array of birds including macaws eating almonds and toucans hidden in the branches.

Crocodile
Birds and crocodiles continued with their endeavors as we peacefully floated by.
Suddenly there was a splashing commotion and in a flash this lizard skittered across the surface of the water.
How does a lizard run on top of water?
I had previously seen this trick of the “Jesus Lizard” on nature programs. They stand upright in the water on their two hind legs, and streak across the water’s surface.
A small reptile with numerous predators, they turn on their racing legs when threatened. It wasn’t a busy river and our pontoon boat had scared him.

Basilisk lizard, Tarcoles River
Basiliscus basiliscus have wide-webbed feet with scaly fringes that expand when they hit the surface of the water. While the front legs remain upright and motionless, the back legs hit the water, creating a pocket of underwater air that supports the lightweight reptile. Simultaneously, their feet are essentially water-pedaling, pushing outward in a way that balances the lizard.
The one we saw was about 12″ long (30 cm) with an additional 8″ (20 cm) of tail. That’s him in the first photo. Doesn’t look like he can fly across water, does he?
How far can they run on top of the water?
We were in a shallow river with natural sand bars, logs, and downed trees; he ran a distance of about 15 feet (4.5 m).

Basilisk Lizard in Belize
But they can go further. Wikipedia says the smaller basilisk lizards can run atop the water’s surface for about 32-64 feet (10-20m). It also says they can run up to 7 mph (11 km/h). Wikipedia info.
Short science video of running basilisk.
I love all lizards, but the basilisk is right there in my top five.
All photos: Athena Alexander

Osprey with fish, Tarcoles River

Chestnut-mandibled Toucan, Tarcoles River

Basalisk lizard in Belize

Costa Rica. Courtesy Wikipedia