Iguanas and Reptiles of Manuel Antonio
Reptiles are everywhere in Manuel Antonio once you slow down: the national park’s management plan records 93 species. The ones visitors notice are the big lizards: the green iguana, the black spiny-tailed iguana (garrobo) sunning near the beach, and the basilisk that can sprint across water. Snakes live here too but are rarely seen. Stay on the trail, watch where you step, and let every reptile be.
Reptiles of Manuel Antonio at a glance
| Reptiles at a glance | |
|---|---|
| Reptile species recorded in the national park | 93, close to 40% of Costa Rica's total (park management plan) |
| Most often seen | Green iguana, garrobo (black spiny-tailed iguana), basilisks, anoles, geckos |
| Best time | Sunny mornings, when lizards bask to warm up; a guided night walk for geckos and sleeping lizards |
| Snakes | Present but seldom seen; most are harmless colubrids. Stay on trails and wear closed shoes |
| Crocodiles | In estuaries and river mouths; the Tárcoles River, on the coast north of Jacó, is famous for large numbers |
| Sea turtles | Olive ridleys nest mainly on Playa Savegre; see our marine life guide |
| Golden rule | Watch from a respectful distance: no feeding, no touching |
Reptiles in Manuel Antonio
Travel Guide › Wildlife › Reptiles and iguanas
According to the park’s 2013–2018 management plan, the 93 reptile species recorded in Manuel Antonio National Park are close to 40% of Costa Rica’s total. Snakes of the colubrid family are the most varied group, with 45 species. The plan also highlights a nocturnal lizard, Lepidophyma reticulatum, as the park’s only reptile endemic to Costa Rica, and notes that small lizards such as anoles help keep insect numbers in check.
Reptiles depend on outside heat to warm up, so mornings are a good time to see lizards basking in sunny spots. This page covers the species visitors see most, then the ones to simply respect from a distance.
Who is who: a reptile identification table
Use this table to put a name to what you see. Sizes are typical adult totals including the tail; details come from Animal Diversity Web, the Reptile Database, the IUCN Red List and the park's management plan (SINAC).
| Reptile | How to recognize it | Where you may see it | Good to know |
|---|---|---|---|
| Green iguana (Iguana iguana) | Green to brown or orange; loose throat dewlap; a large round scale below the ear; up to about 2 m | Branches over rivers, mangroves and the shore | Mostly plant-eating; an excellent swimmer that may drop into water to escape |
| Garrobo, black spiny-tailed iguana (Ctenosaura similis) | Bulky, black or banded gray; rings of sharp spines on the tail | Beaches, beach trees, rocks, sunny ground | Lives in colonies with a pecking order; can bite and tail-lash if cornered |
| Common basilisk (Basiliscus basiliscus) | Long and slender, brown or olive with pale side stripes; males have tall crests; up to about 80 cm | Streams, rivers and wet areas | Runs across water on its hind legs |
| Emerald basilisk (Basiliscus plumifrons) | Bright green with crests on head, back and tail | Vegetation along streams | On the park's reptile list; a prize sighting |
| Anoles, e.g. Golfo Dulce anole (Anolis polylepis) | Small, brown and speckled; males flash an orange-yellow throat fan | Tree trunks, fence posts, garden walls | Head-bob and “push-up” displays to claim territory |
| Common house gecko (Hemidactylus frenatus) | Small, pale, almost translucent skin and big eyes | Walls and ceilings near lights, at night | Chirps after dark; eats insects drawn to lamps |
| Yellow-headed gecko (Gonatodes albogularis) | Tiny; males have a yellow head and a dark bluish body, females are gray | Tree trunks and shaded walls, by day | One of the few geckos active in daylight |
| Green vine snake (Oxybelis fulgidus) | Very slender, bright green, long pointed head; up to about 2 m | Shrubs, vines and low trees | Mild venom meant for small prey; little threat to people who leave it be |
| Central American boa (Boa imperator) | Heavy-bodied with a patterned back; usually 1.3 to 2.5 m | Trees and forest, often resting quietly | Nonvenomous constrictor; most active around dusk |
| Fer-de-lance, terciopelo (Bothrops asper) | Brown with pale-edged dark triangles along the sides; broad, triangular head | Forest floor and leaf litter, mostly at night | Venomous; admire from a distance with a guide |
| Eyelash viper, bocaracá (Bothriechis schlegelii) | Small; raised scales above the eyes like lashes; yellow, green or brown | Vegetation at about hand height | Venomous; look before you touch branches or railings |
| American crocodile (Crocodylus acutus) | Large, long narrow snout, olive-gray | Estuaries, mangroves and river mouths | Vulnerable (IUCN); basks with its mouth open to cool down |
| Sea turtles | Olive ridley, green and hawksbill | Offshore and on nesting beaches | See our marine life guide |
Many of these animals share the grounds at ECOTICA, too. Iguanas bask in the treetops of our 10-acre private reserve, small lizards patrol the garden walls, and now and then a snake rests quietly in the vegetation, a lovely sight from a respectful distance.
Green iguana
Scientific name: Iguana iguana.
Identification
A large lizard that can reach about 2 m from head to tail; most adults weigh 4 to 6 kg. Despite the name, color varies from green to brown and changes with mood, temperature, health and social status. Iguanas are darker in the cool morning, which helps them absorb heat. Young iguanas look more blotchy or banded (Animal Diversity Web). Look for the loose flap of skin under the throat (the dewlap).
Habitat and behavior
Green iguanas are often seen resting on branches, and good basking perches are what they compete for most. In the breeding season males become territorial, bobbing their heads, extending the dewlap and changing color. Females may travel some distance to the same nesting site year after year (Animal Diversity Web). The park’s management plan lists green iguanas in its mangroves and estuaries.
Diet and ecological role
Mostly plants: green leaves and ripe fruit, with the occasional invertebrate. By eating fruit they help disperse seeds, and they are food for larger predators (Animal Diversity Web).
Conservation status
Least Concern on the IUCN Red List (assessed 2022). The park’s management plan also lists it among the park’s reptiles of conservation concern, based on national and international listings.
Black spiny-tailed iguana (garrobo)
Scientific name: Ctenosaura similis. The IUCN calls it the common spiny-tailed iguana; in Costa Rica it is the garrobo, and many visitors call it the “black iguana” or ctenosaur.
Identification
Large and bulky, mostly black or with black bands on a grayish background, often mottled. After basking, the color can lighten and show yellowish or orange markings on the sides. The tail is ringed with rows of sharp, curved spines, which gives the species its name. Males have a clear crest along the back (Animal Diversity Web).
Habitat and behavior
More of a ground-dweller than the green iguana, and able to run on its hind legs. Garrobos live in colonies with a strict pecking order, and males defend territories with head-nodding, “push-ups”, color changes and, if needed, bites and tail-lashing (Animal Diversity Web). In Manuel Antonio they are part of the beach scene: crtrees.org describes garrobos living on the beaches, sometimes on the limbs of the manzanillo tree, and swallowing its fruit whole, even though that fruit is poisonous to people.
Diet
Mostly plants, especially fruit, but adults also take rodents, bats, frogs, small birds and insects. Young garrobos eat mainly insects.
Conservation status
Least Concern on the IUCN Red List (assessed 2015).
Keep your distance: Animal Diversity Web notes that garrobos can bite and wound with their spiny tails when threatened. Never try to pick one up or corner it.
Basilisks: the lizards that run on water
Common basilisk (Basiliscus basiliscus). The park’s reptile list also includes the emerald basilisk (Basiliscus plumifrons).
Identification
A long, slender lizard up to about 80 cm in total, most of it tail. Usually brown or olive (sometimes brighter green) with darker cross bands and cream to yellow stripes along the lip and sides. Males are larger and carry tall, sail-like crests on the head, back and tail (Animal Diversity Web).
Habitat and behavior
Basilisks are active by day and spend their time along streams and waterways, foraging, basking and resting. At night they sleep on perches that can be up to 20 m high. When startled, they rise onto their hind legs and run across the surface of the water, which is why they are nicknamed the “Jesus Christ lizard”. Young, light basilisks can cover 20 m or more this way; larger adults sink after a few meters and swim (Animal Diversity Web).
Diet and ecological role
Omnivores that lean toward animal food: insects and other arthropods, small lizards, snakes, fish, freshwater shrimp and more, with some flowers and fruit. They are predators of many small animals and prey for larger ones.
Conservation status
Common basilisk: Least Concern (IUCN, assessed 2016). Emerald basilisk: Least Concern (IUCN, assessed 2013).
Anoles and geckos: the little lizards you will meet everywhere
The big iguanas get the photos, but the reptiles you will meet most often in Manuel Antonio are small: anoles on every sunny trunk and geckos on every warm wall after dark. Spend five quiet minutes watching one and you will see a whole little drama of territory, courtship and hunting.
Anoles: the flag-wavers
Anoles are slim lizards a few centimeters long that perch head-down on trunks and posts, watching for insects. Males carry a fold of skin under the chin, the dewlap, which they flick open like a colored flag while bobbing their heads and doing quick “push-ups”. The display tells rivals to keep away and tells females who is in charge. In this corner of Costa Rica, look for the Golfo Dulce anole (Anolis polylepis), a brown, speckled lizard of the southern Pacific slope and western Panama whose males show an orange-yellow dewlap (Reptile Database). The park's management plan notes that small lizards like these help keep insect numbers in balance.
Geckos: the night shift
If you hear a soft chirping from the ceiling in the evening, meet the common house gecko (Hemidactylus frenatus). Originally from Asia, it has spread through human settlements across the tropics, including Costa Rica, where researchers at the Universidad de Costa Rica have studied it. It is pale and almost translucent, with large eyes, and it waits beside lamps for moths and mosquitoes, which makes it a welcome housemate. Like many geckos, it climbs walls and ceilings on toe pads covered in microscopic structures that grip almost any surface.
By day, scan shaded tree trunks for the tiny yellow-headed gecko (Gonatodes albogularis), one of the few geckos active in daylight. Only the males wear the bright yellow head; females are a quiet gray.
A clever escape
Many lizards, from anoles to iguanas, can drop part of the tail when grabbed, leaving a predator with a wriggling decoy. In green iguanas a new tail grows back within about a year (Animal Diversity Web). It is one more reason to admire lizards without touching them: that tail is costly to replace.
Snakes, crocodiles and sea turtles
Snakes
The park’s management plan lists dozens of snake species, most of them from the colubrid family. It also lists venomous species, including the fer-de-lance (terciopelo, Bothrops asper), the eyelash viper (bocaracá, Bothriechis schlegelii), coral snakes (Micrurus) and the yellow-bellied sea snake. Most visitors never see a snake. Simple habits keep it that way:
- Stay on marked trails. SINAC asks visitors not to leave permitted areas.
- Wear proper closed footwear on forest trails, as SINAC recommends (sandals are not recommended).
- Look before you put your hands on railings, branches or rocks, and before you sit.
- If you see a snake, stop, step back and let it move away. Never try to catch, move or photograph it up close. A guide can point one out safely from a distance.
- If someone is bitten, get medical help immediately.
American crocodile
The management plan records the American crocodile (Crocodylus acutus) and the spectacled caiman in the park’s estuaries and mangroves. The American crocodile is Vulnerable on the IUCN Red List (assessed 2022). Keep well back from the water’s edge in estuaries and river mouths, and never feed them.
Sea turtles
Olive ridley turtles nest mainly on Playa Savegre, in the park’s southern sector, and green and hawksbill turtles have occasionally been recorded nesting there (management plan). If you ever come across a nesting turtle or hatchlings, keep your distance, keep lights off and let them reach the sea on their own.
Snakes you might see, and how to enjoy them safely
Snakes are part of what makes this forest so rich, and seeing one with a guide is often a highlight of the trip. The vast majority are harmless to people and far more interested in staying hidden than in you. Here are the ones visitors most often meet, and how to enjoy them in comfort.
The ones you are most likely to see
- Green vine snake (Oxybelis fulgidus). Impossibly thin and leaf-green, it can reach about 2 m and drapes itself through shrubs like a vine. It has a mild venom for subduing lizards and small prey, which poses little threat to people who leave it alone.
- Central American boa (Boa imperator). A heavy, beautifully patterned constrictor, usually 1.3 to 2.5 m long, with no venom at all. Boas often rest motionless in trees for hours and become more active around dusk. Spotting one coiled on a branch is a wonderful, calm encounter, sometimes right here on the grounds at ECOTICA.
- Fer-de-lance (terciopelo, Bothrops asper) and eyelash viper (bocaracá, Bothriechis schlegelii). The two venomous species guides point out most often. The fer-de-lance is a ground snake of the leaf litter, mostly active at night; the small eyelash viper waits in vegetation, sometimes in bright yellow. Both are best admired through a guide's flashlight beam or camera zoom.
Easy habits for every walk
The habits in the section above, staying on trails, wearing closed shoes and looking before you reach, are what keep encounters relaxed. Two more help: carry a small flashlight after dark, and walk paths rather than tall grass at night, when many snakes hunt.
Good to know: Costa Rica is a world leader in antivenom
The Instituto Clodomiro Picado of the Universidad de Costa Rica produces roughly 120,000 to 130,000 vials of antivenom a year and supplies the national health system (CCSS) and private hospitals. In the very rare case of a bite, the university's advice is clear and simple:
- Stay calm and keep the bitten limb still.
- Go straight to the nearest hospital or clinic with antivenom; there is no need to catch or identify the snake.
- Skip the movie remedies: no tourniquet, no cutting, no suction and no ice, all of which waste time or cause harm.
The best way to see snakes is with an expert. Planning ahead? Book a guided night walk with our concierge, where guides know exactly where to look and how close is close enough.
Crocodiles: from quiet estuaries to the Tárcoles River
The American crocodile (Crocodylus acutus) is the largest reptile you can see in this part of Costa Rica. Around Manuel Antonio it lives in quiet estuaries and mangroves, as the park's management plan records, and is usually seen as a pair of eyes and a long snout drifting at the surface, or a still, olive-gray shape basking on a muddy bank.
The crocodiles of the Tárcoles River
For a near-certain look at big crocodiles, the famous place is the Tárcoles River, which meets the Pacific north of Jacó on the coastal highway (Route 34) that many visitors drive between San José and Manuel Antonio. Scientific surveys have reported between 10 and 35 crocodiles per kilometer of river there, far above the average of about 3 per kilometer found in other Pacific estuaries of Costa Rica (Mauger and colleagues, 2012, Revista de Biología Tropical). Remarkably, this thriving population lives in what is often described as one of the most polluted rivers in Central America. From the bridge, travelers can usually watch several large animals resting on the sandbanks below; river boat tours give a closer, guided view.
Getting here from San José? Our transportation guide covers the route, and our private airport transfer makes the drive effortless. Want to add a river tour to your plans? Ask our concierge for details.
Crocodile behavior worth watching
- Open-mouthed basking. A crocodile lying with its jaws wide open is not threatening anyone; it is releasing heat, much as a dog pants.
- Patience as a strategy. Crocodiles can stay nearly motionless for hours, which is why a calm, distant view is the perfect way to enjoy them.
- Most of them are small. In the 2012 Pacific survey, more than half of the crocodiles counted were hatchlings or juveniles under about 1.25 m.
Closer to home, mangrove boat and kayak trips through the estuaries near Quepos sometimes reveal a crocodile or a spectacled caiman along the banks, together with herons and kingfishers. See our ocean and boat tours. Enjoy them from the boat or the bridge, and never feed them: crocodiles stay wild and healthy when they keep their natural wariness of people.
Sea turtles, briefly
Sea turtles are the gentlest reptiles of all. Olive ridleys nest mainly on Playa Savegre, as described above, and turtles are often seen from boats offshore. Our ocean and marine life guide tells their story in full.
How to watch reptiles well
- Don’t feed iguanas or garrobos. The park’s management plan lists garrobos, basilisks and green iguanas among the animals involved in conflicts with visitors. Feeding wildlife is prohibited in the park (SINAC).
- Don’t touch or pick them up. SINAC asks visitors not to touch wild animals, and large lizards can bite and scratch.
- Give basking lizards space. Chasing a lizard off its sunny spot costs it warmth and energy.
- No flash, and keep lights low around animals at night.
More on responsible viewing in our wildlife guide.
How reptiles live: behavior worth watching
Once you know a little about how reptiles live, every lizard on a rock becomes a story. These are the behaviors worth watching for.
Living by the sun
Reptiles take their body heat from their surroundings. On a cool morning a green iguana climbs to a sunny branch, often looking darker so it absorbs heat faster, and stays there until it is warm enough to digest its leafy meals. Around midday many lizards move into shade so they do not overheat. Green iguanas even have a “third eye”, the parietal eye on top of the head, a light-sensitive organ that works as a meter for sunlight (Animal Diversity Web).
Signals and displays
- Head-bobbing is the reptile language of the forest: male iguanas, garrobos and anoles all bob to defend territory and court females.
- Dewlaps, the throat flaps, are raised to look bigger and to flash color at rivals.
- Color changes in iguanas reflect temperature, mood and social standing, so the same animal can look quite different in the morning and the afternoon.
Into the water
Green iguanas favor branches over rivers for good reason: they are excellent swimmers and will drop into the water and dive to escape predators such as hawks (Animal Diversity Web). Basilisks take the opposite approach and sprint across the surface.
A reptile year
Green iguanas breed in the dry season, so that their young hatch in the wet season when food is plentiful. A female usually lays 10 to 30 eggs in a burrow, which take roughly 90 to 120 days to hatch, and hatchlings break out of the shell with a tiny egg tooth that soon falls off. In the wild an iguana lives about 8 years on average (Animal Diversity Web). If you visit early in the green season, look for bright green baby iguanas in low vegetation near water.
Snakes and their senses
That flickering tongue is how a snake “smells”: it collects scent particles from the air and carries them to a special organ in the roof of the mouth. A snake tasting the air is simply getting its bearings, and a calm observer is just part of the scenery.
Where visitors may encounter reptiles
Reptiles are easiest to see when they are warming up, so look in sunny spots in the morning. Nothing here is guaranteed.
- Beaches and beach trees for garrobos, and trees along the shore and rivers for green iguanas. Beaches inside the park are covered in our national park guide; our beach guide covers the rest.
- Streams and wet areas for basilisks.
- Forest trails for anoles and other small lizards, and, with a guide’s help, the occasional snake at a safe distance. ECOTICA‘s concierge can book a guided park walk through our wildlife and nature tours.
Don’t sit under the beach trees without checking what they are: some are manzanillo, a poisonous tree. Our plants and rainforest guide shows how to recognize it.
Reptiles at ECOTICA and on a guided night walk
You do not need to go far to meet Manuel Antonio's reptiles. ECOTICA sits on its own 10-acre private rainforest reserve, a few minutes from the national park, and the same animals that live in the park share our gardens.
A reptile walk around the grounds
- Mid-morning: scan the treetops and palm crowns for iguanas basking in the sun, and the garden walls and tree trunks for anoles flashing their dewlaps.
- Midday: watch shaded trunks for the little yellow-headed gecko while you cool off by the pool.
- Evening: the lights along the paths bring out house geckos hunting moths. Now and then, a snake rests in the vegetation; enjoy it from a respectful distance and let our team know, and they will be happy to help you identify it.
Between the lizards you may well spot howler, capuchin and squirrel monkeys, sloths, coatis, agoutis, deer, toucans and scarlet macaws, all part of daily life at ECOTICA, never on a schedule. Read more in wildlife where you stay.
After dark with a guide
Night is when the forest's quieter reptiles show themselves. On a guided night walk, flashlights pick out basilisks and iguanas asleep on branches, geckos on the hunt, and, with luck, a boa or an eyelash viper waiting in the leaves, together with frogs, insects and spiders. Our guide to frogs, butterflies and the night has more on what comes out after sunset.
Planning this ahead of time? Book a night walk with our concierge, and come back to live music at YOLO Social afterwards. Still choosing dates? Check rates for a bungalow or suite.
Iguanas and reptiles: questions and answers
Are iguanas dangerous?
Green iguanas are calm plant-eaters that prefer to slip away. Like any wild animal they can bite or scratch if handled, so enjoy them from a respectful distance and never feed them.
What is the difference between a green iguana and a garrobo?
The green iguana is a tree-climber with a dewlap and a big round scale below the ear, usually green to orange. The garrobo, or black spiny-tailed iguana, is bulkier, black or banded gray, lives more on the ground and has rings of spines on its tail.
Will I see snakes in Manuel Antonio?
Most visitors see few or none, because snakes are shy and well camouflaged. A guided walk, especially at night, is the best way to see one safely, and at ECOTICA one occasionally rests in the garden vegetation.
What should I do if I see a snake on the trail?
Stop, step back slowly and give it room to move on; snakes are not interested in people. Enjoy it with your camera zoom, and let a guide or park ranger know if it is on a busy path.
What are the little chirping lizards in my room at night?
Those are house geckos, harmless insect-eaters that wait near lights for moths and mosquitoes. Consider them friendly housemates.
Are there crocodiles in Manuel Antonio?
Yes, American crocodiles live in the estuaries and mangroves of the area, as the park's management plan records. They keep to the river mouths and mangroves; enjoy them from a boat or a distance and never feed them.
Where can I see big crocodiles near Manuel Antonio?
The Tárcoles River, on the coastal highway north of Jacó, is famous for its high numbers of large crocodiles, easily seen from the bridge or on a river boat tour. Our concierge can help you plan it.
What time of day is best for seeing reptiles?
Sunny mornings, when lizards climb into the light to warm up. For geckos, sleeping lizards and snakes, a guided night walk is ideal.
Can I see sea turtles in Manuel Antonio?
Olive ridleys nest mainly on Playa Savegre in the park's southern sector, and turtles are often seen from boats offshore. See our ocean and marine life guide.
Is Costa Rica well prepared for snakebites?
Yes. The Instituto Clodomiro Picado of the Universidad de Costa Rica produces antivenom for the country's hospitals and for other nations, and bites are very rare for visitors who stay on trails and wear closed shoes.
Keep exploring
Keep exploring: meet the rest of the forest in the wildlife guide, then birds, monkeys, sloths and coatis and raccoons. Plan your park day with the national park guide, learn to recognize the manzanillo tree in plants and rainforest, and read responsible wildlife watching before you go.
Came across an injured iguana, snake or turtle? Follow these steps and call the right people. For a snakebite or any human emergency, our health and safety guide keeps the numbers ready.
Arrive with everything ready
Come to watch iguanas basking on sun-warmed rocks; we will have the rest of your stay arranged before you land:
- Book your tours: a guided walk in the national park where a naturalist points out reptiles hidden in plain sight, or an afternoon of zip lines, rafting or a mangrove boat trip
- Reserve Jungle Spa: massages, couples treatments, facials and body rituals, and a chance to slow down like a lizard in the sun
- Airport transportation: a private transfer from San José, US$195 each way for up to 5 people, with time to rest before your first iguana encounter
- Concierge requests: dinners, celebrations or any special request, handled while you are out reptile-spotting
- Stay at ECOTICA: check dates and rates for our bungalows and suites and plan your days around the reptiles of the coast
Sources for our iguana and reptile guide
- SINAC – Manuel Antonio National Park (official English page: park overview for reptile watchers)
- SINAC – Parque Nacional Manuel Antonio (official Spanish page: hours and rules to plan a reptile walk)
- SINAC – Plan General de Manejo, Parque Nacional Manuel Antonio 2013–2018 (PDF; reptile and amphibian species recorded in the park)
- Animal Diversity Web (University of Michigan) – Green iguana (Iguana iguana): diet, behaviour and range
- Animal Diversity Web (University of Michigan) – Black spiny-tailed iguana (Ctenosaura similis): the garrobo seen on coastal rocks
Photos: G.isle px., Alexey Demidov, Alan Kotok, Gavin Fregona, William Warby, René Wechet / Pexels.
