Frogs, Butterflies & the Forest at Night
The monkeys and sloths get the headlines, but some of Manuel Antonio’s most unforgettable animals are small, brightly colored or only awake after dark. A blue morpho flashing through a sunbeam, a red-eyed tree frog clinging to a leaf by a pond, a kinkajou feeding in the canopy by flashlight: these are the moments people talk about at breakfast.
This guide introduces the frogs, butterflies, insects and night animals of the Central Pacific, and explains how to enjoy a night walk well.
The small and the nocturnal, in brief
| Quick facts | |
|---|---|
| Amphibians | 56 species recorded in Manuel Antonio National Park, about 30 percent of Costa Rica’s total; tree frogs (Hylidae) are the largest family with 14 species (park management plan) |
| Signature frogs | Red-eyed tree frog, eight glass frog species, green-and-black and granular poison dart frogs |
| Best frog season | The rainy season, about May to October (IMN), when ponds fill and frogs call and breed |
| Butterflies | Blue morpho, owl butterflies, glasswings and longwings in gardens and forest edges |
| Night mammals | Kinkajous, opossums, two-toed sloths, raccoons, pacas and around 57 bat species |
| Night walks | Guided walks start around dusk in private reserves; the park’s official guides offer them only in special seasons, November to April (SINAC) |
| Golden rules | Red or dimmed light, no touching, no flash, closed shoes |
Why Manuel Antonio is frog country
Frogs need moisture, warmth and still water to breed, and the Central Pacific offers all three. Manuel Antonio National Park has recorded 56 amphibian species from 13 families, roughly 30 percent of all the amphibians known in Costa Rica, in a park you can cross on foot in a morning (park management plan, SINAC). Tree frogs are the richest family, with 14 species, and most of the park’s amphibians depend on forest cover to survive. The list also includes salamanders and two caecilians, legless burrowing amphibians that few visitors ever see.
Three of the park’s amphibians are endemic to Costa Rica: the Golfo Dulce poison dart frog (Phyllobates vittatus), the toad Incilius aucoinae and the caecilian Dermophis occidentalis. That makes every frog you find here part of something rare.
The rainy season is frog season
On Costa Rica’s Pacific slope, the national weather service (IMN) describes a rainy season from May to October, with September and October the wettest months. For frogs, this is the moment everything happens. Ponds, puddles and water-filled tree holes appear, males call to attract females, and eggs are laid on leaves, in foam nests or in tiny pools. An evening after a warm afternoon shower is often the liveliest of all: the forest fills with whistles, clicks and trills.
The green season has other gifts too. Rain tends to fall in the afternoon and early evening on the Pacific side (IMN), the forest is at its most lush, and the trails are quieter. If you visit in the drier months, frogs are still here, sheltering in damp leaf litter, bromeliads and along streams, and a good guide knows exactly where to look. Our guide to the best time to visit explains each season in more detail.
Red-eyed tree frog (Agalychnis callidryas)
Bright green body, blue and yellow flanks, orange feet and those huge crimson eyes: the red-eyed tree frog is probably the most photographed frog in the world, and it is on the park’s list of forest-dependent amphibians (park management plan). In Costa Rica it is known as rana calzonuda, the frog in shorts, for the colored patches on its thighs.
A night creature
By day it sleeps flat against the underside of a leaf, eyes closed, legs tucked in and its bright colors hidden, so it looks like a small green bump. At night it wakes to hunt insects, climbing with sticky toe pads. If disturbed, it can suddenly open its red eyes and flash its colors, a surprise that may give a predator a moment’s pause.
Eggs that know when to run
Red-eyed tree frogs lay clutches of jelly-covered eggs on leaves hanging over water. When the tadpoles hatch, they drop straight into the pond below. Research led by Karen Warkentin of Boston University, much of it at the Smithsonian Tropical Research Institute, showed that embryos normally hatch after six to eight days but can hatch up to 30 percent earlier if a snake or wasp attacks the clutch. They tell the vibrations of an attack apart from the drumming of rain, and can break out of the egg within seconds.
Where and when to look
Ponds and slow streams with overhanging vegetation, on warm, humid nights, especially in the rainy season when they gather to breed. Look on leaves and stems a little above the water, and listen for a short “chuck” call. A guide’s trained eye makes all the difference: book a guided night walk and let an expert show you where they rest.
Glass frogs, rain frogs and the voices of the dark
Glass frogs
The park’s management plan lists eight glass frog species, including Fleischmann’s glass frog (Hyalinobatrachium fleischmanni), the reticulated glass frog (Hyalinobatrachium valerioi) and the emerald glass frog (Espadarana prosoblepon). Glass frogs are small and lime green from above, but their bellies are transparent: look from below and you can see the heart beating and the internal organs. They live along forest streams, where they lay their eggs on the underside of leaves overhanging the water. In several species the males guard the clutch, keeping the eggs moist and protecting them from wasps (Animal Diversity Web). Finding a glass frog sitting beside its eggs on a leaf is one of the great small thrills of a night walk.
Rain frogs
Rain frogs of the genera Craugastor and Pristimantis are the quiet, brown, leaf-litter frogs that guides often find on the forest floor or on low leaves. The park lists eight species. Many of them skip the tadpole stage entirely: their eggs, laid on land, hatch straight into tiny froglets, which frees them from needing ponds at all.
More voices to listen for
- Túngara frog (Engystomops pustulosus). A small frog that whips up foam nests in puddles. Its call, a falling whine followed by “chucks”, has been studied for decades at the Smithsonian Tropical Research Institute.
- Gladiator frog (Boana rosenbergi, listed in the plan as Hypsiboas). Males build small mud basins at the edge of streams and defend them fiercely; their call sounds like a hammer tapping.
- Milk frog (Trachycephalus). A big tree frog that releases a sticky, milky secretion when handled, one more reason to keep your hands to yourself.
- Smoky jungle frog (Leptodactylus savagei). One of the largest frogs in Central America, a powerful hunter of the forest floor.
- Cane toad (Rhinella marina). The big toad you may see on paths and lawns after dark.
Listening is half the joy. Stand still for a minute with your light off and let the sounds layer up around you: frogs, katydids, crickets and the occasional call of an owl.
Poison dart frogs of the Central Pacific
Unlike most frogs, poison dart frogs are active by day, and their bright colors are a warning to predators. Manuel Antonio’s management plan records three species, and a morning walk on a damp trail is the best time to meet them.
Green-and-black poison dart frog (Dendrobates auratus)
Glossy black with swirls of green or blue-green, this is the poison frog you are most likely to see in the Central Pacific lowlands. It hops through the leaf litter hunting tiny ants and mites. The males are devoted fathers: after the eggs hatch, they carry the tadpoles on their backs to small pools of water in tree holes or plants. The plan notes it tolerates some disturbance of its habitat, so it can turn up near forest edges as well as deep in the woods.
Granular poison frog (Oophaga granulifera)
A small, bumpy-skinned frog, usually bright red-orange on the back with green or blue-green legs. It lives only in the humid lowland forests of southwestern Costa Rica and adjacent Panama and is listed as Vulnerable by the IUCN. Its parenting is remarkable: the mother carries each tadpole to its own tiny pool in a leaf axil or bromeliad and returns to feed it with unfertilized eggs (AmphibiaWeb).
Golfo Dulce poison dart frog (Phyllobates vittatus)
Black with two bright orange-gold stripes down the back, this frog is endemic to Costa Rica, found in the wet lowlands of the southern Pacific, and the park lists it among its endemic species. It belongs to the same genus as the golden poison frog of Colombia, but is a far milder relative.
Admire without touching
Poison frogs get their toxins largely from the small insects they eat, so wild frogs can carry skin toxins. Simply enjoy them where they sit: never pick one up, and keep sunscreen and repellent off the leaves they rest on. A guided morning walk in the national park or a reserve is the easiest way to find them; see our wildlife and nature tours.
Blue morphos and the butterflies of Manuel Antonio
Blue morpho (Morpho peleides)
No sight says “rainforest” quite like a blue morpho drifting along a trail, flashing electric blue with every wingbeat and then vanishing as it lands. Its wingspan reaches about 5 to 8 inches (13 to 20 cm), according to the University of Florida’s entomology program. The blue is not pigment but structure: microscopic ridged scales reflect and amplify blue light, the Smithsonian explains. The undersides are brown with a row of eyespots, perfect camouflage when the wings close. Adults feed on fermenting fruit and tree sap rather than flower nectar, which is why they are often seen low over the forest floor or near fallen fruit.
Owl butterflies (Caligo)
Large, brown and quietly beautiful, with a huge eyespot on each hindwing that resembles an owl’s eye. They are most active around dawn and dusk, and like morphos they feed on rotting fruit. Look for them in shady gardens and along forest edges as the light fades.
Glasswings and longwings
- Glasswing butterfly (Greta oto). Its wings are clear like window glass, edged in dark brown, so it almost disappears in flight.
- Longwings (Heliconius). Slender, long-winged butterflies in orange, black, yellow or red. Unusually for butterflies, they can feed on pollen as well as nectar, which helps them live for months.
Where to see butterflies
Butterflies love sunny gaps, forest edges and flowering gardens, and they are most active on bright mornings. Many of the most colorful species visit flowering shrubs such as heliconias and lantanas. At ECOTICA, butterflies drift through the 10-acre rainforest gardens most days, along with toucans, scarlet macaws and many other birds, so a slow walk around the grounds after breakfast can be wonderfully rewarding. Our plants and rainforest guide explains the flowers they depend on, and our post on wildlife where you stay shares the best hours to look.
Leafcutter ants, tarantulas, stick insects and katydids
Leafcutter ants
Follow a moving green line across the trail and you will find leafcutter ants (Atta), each worker carrying a piece of leaf many times its own weight. The surprise is that they do not eat the leaves. Underground, the colony uses the leaf fragments to grow a fungus garden, and the fungus is what feeds them. Ants and fungus depend on each other completely, and the Smithsonian Tropical Research Institute notes that these ants first domesticated fungi nearly 60 million years ago. A large colony can hold millions of ants, and their highways stay busy by night as well as by day.
Tarantulas
Several tarantula species live in Costa Rica’s forests. They spend the day in silk-lined burrows in banks and tree roots and come to the entrance at dusk to wait for passing insects. A guide may show you a burrow and gently coax its owner to the doorway with a twig. Tarantulas are shy and slow to anger, but they can flick irritating hairs from their abdomen when bothered, so admire them without handling.
Stick insects
Stick insects are masters of disguise: long, thin and brown or green, they sway gently like a twig in the breeze. Most feed on leaves at night, which is when guides are most likely to spot one moving. Some are remarkably long, and once you see your first one, you start noticing them everywhere.
Katydids
Katydids are the relatives of grasshoppers that supply much of the forest’s night music. Some look exactly like a green leaf, complete with veins, brown “dead” patches and ragged edges that mimic insect damage. Others mimic lichen or moss. Their calls, made by rubbing their wings together, are part of the chorus you hear from your balcony at night.
Also look for
- Fireflies and click beetles glowing along forest edges on humid evenings.
- Golden orb weavers (Trichonephila), whose big webs shine gold in the morning light.
- Moths of every size and pattern drawn to porch lights, from tiny jewels to giant silk moths.
Children love this hidden world, and it is a wonderful way to spend a rainy evening. Book a family night walk through our concierge and we will arrange a guide who enjoys showing it to young explorers.
Kinkajous, bats and other night mammals
When the monkeys settle down for the night, a different cast takes over the forest. The national park’s species list includes many nocturnal mammals, and the forests around Manuel Antonio share most of them.
Kinkajou (Potos flavus)
Locally called martilla, the kinkajou is a golden-brown relative of raccoons and coatis that lives in the treetops. It is strictly nocturnal and arboreal, weighs about 2 to 4.6 kg and has a fully prehensile tail it uses to hang while feeding (Animal Diversity Web). Fruit, especially figs, makes up most of its diet, and it laps nectar with a long, extendable tongue, pollinating flowers and spreading seeds as it goes. Guides often find kinkajous by the shine of their eyes in a fruiting tree.
Bats: the park’s most diverse mammals
About 57 bat species have been recorded in Manuel Antonio National Park, more than half of all its mammal species (park management plan). They pollinate flowers, spread seeds and eat enormous numbers of insects. Look for:
- Spectral bat (Vampyrum spectrum). The largest bat in the Americas, with a wingspan of 76 to 91 cm and sometimes more than a meter. It hunts birds, rodents and other bats, and mated pairs share the care of their single young (Animal Diversity Web). It is listed in the park and rarely seen, a true prize.
- Greater fishing bat (Noctilio leporinus). Skims over calm water and rivers, catching small fish with its long, hooked feet.
- Tent-making bats (Uroderma bilobatum). Bite along the ribs of large leaves until they fold into a tent, then roost underneath. Our monkeys guide explains how squirrel monkeys have learned to check these tents.
- Proboscis bats (Rhynchonycteris naso). Tiny bats that roost in neat lines on tree trunks over water, often visible on mangrove and river trips.
More night mammals
- Hoffmann’s two-fingered sloth, whose activity spreads across day and night (The Sloth Conservation Foundation). See our sloth guide.
- Raccoons, mostly nocturnal and fond of places near water. Our coatis and raccoons guide tells them apart.
- Common opossum and Central American woolly opossum, both on the park’s list.
- Paca (tepezcuintle), a large, spotted rodent of the forest floor.
- Ocelot and margay, recorded in the park but seen far less often.
- Owls, including the spectacled owl and the black-and-white owl, both on the park’s list of forest-dependent birds.
Many of the area’s daytime animals live right on ECOTICA’s grounds too: all three monkey species, both sloths, coatis, agoutis, deer and reptiles are seen there, so the wildlife watching can carry on from your terrace long after the tour ends.
Who comes out at night
A quick guide to the animals you may meet after dark around Manuel Antonio. Sightings are never guaranteed, and that is part of the magic: every night walk is different.
| Animal | When | Where to look | Tip |
|---|---|---|---|
| Red-eyed tree frog | After dark, rainy season best | Leaves above ponds and slow streams | Listen for a short “chuck” |
| Glass frogs | After dark | Leaves over forest streams | Check the underside of leaves for eggs |
| Rain frogs | Dusk and night | Leaf litter and low leaves | Scan the ground slowly |
| Túngara frog | Night, after rain | Puddles and roadside pools | Look for white foam nests |
| Kinkajou | Night | Fruiting trees in the canopy | Look for eyeshine high up |
| Bats | From dusk | Over water, along trails, under leaf tents | Watch the sky at sunset |
| Two-fingered sloth | Day or night | Canopy and mid-level branches | Slow, deliberate movement |
| Tarantulas | Dusk and night | Burrows in banks and roots | Admire from outside the burrow |
| Stick insects and katydids | Night | Twigs and leaves at eye level | Look for a “leaf” that walks |
| Snakes such as snail-eaters (Sibon) | Night | Low vegetation | Your guide keeps a respectful distance |
| Owls | Dusk and night | Forest edges and tall trees | Listen for calls, then look |
Species from the national park’s management plan (SINAC). For snakes, lizards and the eyelash viper that sometimes rests on low branches, read our reptiles and iguanas guide. For the daytime rhythm of the forest, see Manuel Antonio wildlife hour by hour.
Night walks: what to expect, what to wear, how to do it well
What to expect
Most night walks begin around dusk and often last a couple of hours, moving slowly along forest trails with a naturalist guide and a small group. You will walk short distances, stop often and spend long minutes looking at a single leaf. Manuel Antonio National Park closes at 3:00 p.m., so most night walks take place on private reserves and forest near Manuel Antonio. According to SINAC, the park’s official guides run night walks at 5:30 p.m. on Wednesdays, Thursdays and Fridays only in special seasons, from November to April; our national park guide has their contact details.
How guides find animals
- Eyeshine. Many animals have a reflective layer behind the eye. A light held near the guide’s own eyes makes spiders, frogs, kinkajous and opossums glow back.
- Sound. Guides recognize frog calls by species and follow them to the caller.
- Knowledge. They know which ponds the tree frogs use this month, which bank holds a tarantula burrow and which tree is fruiting.
- Patience. A good guide scans every layer, from the leaf litter to the canopy, and lets the group take its time.
What to wear and bring
- Closed shoes with good grip, or rubber boots in the rainy season; trails can be muddy.
- Long, lightweight trousers and a light long-sleeved top.
- A light rain jacket from May to November.
- Insect repellent, applied before you set out and away from the leaves you touch.
- A small flashlight or headlamp, ideally with a red-light setting; many guides provide lights.
- A camera or phone that works in low light. Your guide will help you with lighting.
Ethics after dark
- Gentle light. Use red or dimmed light where possible, keep beams off animals’ eyes for long, and switch off when you are simply listening.
- No touching. Frogs absorb substances through their skin, and sunscreen, repellent or even the oils on our hands can harm them. Never pick up an animal, and never let a guide handle one for a photo.
- Turn off the flash. Flash startles animals that see well in the dark; your guide’s light is enough.
- Stay on the trail and step carefully. Look before you lean on a tree or put your hand on a railing.
- Keep voices low. Quiet groups see more, and you will hear the forest at its best.
Planning this ahead of time? Book a guided night walk with our concierge or ask us for details; see also our wildlife and nature tours. Back at ECOTICA, a nightcap at YOLO Social, with live music every night, is the perfect way to share the frogs you found.
Frogs, butterflies and night walks: questions and answers
Can I see red-eyed tree frogs in Manuel Antonio?
Yes, they are part of Manuel Antonio’s amphibian community, though they are active only at night and hide by day. A guided night walk near ponds or slow streams, especially in the rainy season, gives you the best chance.
Are there poison dart frogs near Manuel Antonio?
Yes. The national park records the green-and-black poison dart frog, the granular poison frog and the endemic Golfo Dulce poison dart frog. They are active by day, so look for them on morning walks, and never touch them.
What is the best season for frogs?
The rainy season, roughly May to October on the Pacific side, when ponds fill and frogs call and breed. Warm, humid evenings after an afternoon shower are often the liveliest.
Can I do a night tour inside Manuel Antonio National Park?
The park closes at 3:00 p.m. According to SINAC, its official guides offer night walks at 5:30 p.m. on Wednesdays, Thursdays and Fridays only in special seasons (November to April); at other times, night walks take place in private reserves nearby.
What should I wear on a night walk?
Closed shoes with good grip, long lightweight trousers, a light long-sleeved top and, in the rainy season, a light rain jacket. Bring insect repellent and a small flashlight, ideally with a red-light mode.
Are night walks suitable for children?
Yes, most children love them: the pace is slow, the distances are short and every leaf can hide a surprise. Ask our concierge to arrange a guide who enjoys working with families.
Where can I see blue morpho butterflies?
Along sunny trails, forest edges and gardens, especially on bright mornings; they often fly low near fallen fruit. Butterflies are part of daily life in ECOTICA’s rainforest gardens.
Why should I use a red light at night?
A dim or red light is gentler on animals’ night vision and helps them carry on behaving naturally, which also means better sightings for you. Keep beams off animals’ eyes and switch off when you are simply listening.
Are tarantulas and other night creatures dangerous?
Tarantulas are shy and rarely a concern when left alone, though they can flick irritating hairs if bothered. Follow your guide, look before you touch railings or trees, and admire every animal without handling it.
Can ECOTICA book a night walk for me?
Yes. Our concierge books guided night walks with experienced local naturalists. Send your dates through our tours form and we will take care of the rest.
Keep exploring
Keep exploring: our wildlife overview brings all the animals together, the ocean and marine life guide takes you out to the whales and dolphins, the birds guide covers toucans and macaws, and plants and rainforest explains the forest that shelters them all. Plan your days with our itineraries, then check dates and rates at ECOTICA.
Found an animal that needs help? Here is exactly what to do and who to call. For people, our health and safety guide keeps emergency numbers close at hand.
Arrive with everything ready
Tell us your dates and we will have the best of Manuel Antonio waiting for you before you land:
- Book your tours: Manuel Antonio National Park with a naturalist guide, boat trips, zip lines, rafting and more
- Reserve Jungle Spa: massages, couples treatments, facials and body rituals
- Airport transportation: a private transfer from San José, US$195 each way for up to 5 people
- Concierge requests: dinners, celebrations and anything special
- Stay at ECOTICA: check dates and rates for our bungalows and suites
Where our facts come from
- SINAC – Plan General de Manejo, Parque Nacional Manuel Antonio 2013–2018 (PDF; amphibian, bat and mammal lists)
- Boston University – How red-eyed treefrog embryos hatch early to escape predators (Warkentin lab)
- Animal Diversity Web (University of Michigan) – Kinkajou (Potos flavus)
- Animal Diversity Web (University of Michigan) – Spectral bat (Vampyrum spectrum)
- University of Florida IFAS – Blue morpho butterfly, Morpho peleides (EDIS IN1101)
Photos: Gabriel Rondina, Andres Campos, Erick Arce, Enrique Hidalgo, Karolina, cassius cardoso / Pexels.
