All 4 in 3 days here: ~50%
Ostional Wildlife Refuge
🇨🇷 Costa Rica
Nicoya Peninsula, Costa Rica 727 spp. recorded
Ostional Wildlife Refuge protects one of the two most important olive ridley turtle nesting beaches on Earth. During peak season (September–November), up to 500,000 turtles emerge from the Pacific in a single arribada — an ancient synchronized mass-nesting event that occurs in only a handful of places worldwide.
9.958° N 85.653° W
🦜 Nature
337 Species sighted
19,719 Verified sightings From 2019 to 2026
Oct Best month
⭐ Iconic Species
📊 Most Spotted
⭐ Iconic Species
📊 Most Spotted
📊 Most Spotted
⭐ Iconic Species
📊 Most Spotted
📊 Most Spotted
📊 Most Spotted
⭐ Iconic Species
🌙 Most active after dark
+ 471 more species with insufficient data
Challenges you can complete here
Recent sightings in Ostional Wildlife Refuge
LIVEiNaturalistSighting Calendar
How many species you'd see in a day
36Jan
41Feb
37Mar
32Apr
37May
38Jun
42Jul
36Aug
36Sep
43Oct
35Nov
40Dec
Sighting Zones
Warmer areas are where all species together are recorded most often.
-
Reserva Biológica Nosara (Lagarta)
Daily sight. prob.vs avg -
Albergue y Camping Refugio de Tortugas
Daily sight. prob.vs avg
Black Spiny-tailed Iguana>90%+10%
Green Iguana~90%+30%
Mantled Howler Monkey~80%≈
Variegated Squirrel~80%+10%
Köhler’s Vine Snake~60%+30%
Giant Marine Toad~60%≈
Black Vulture~60%-20%
Mexican Smilisca~50%+10%
Rose-bellied Lizard~50%+10%
Black-necked Centipede Snake~50%+30%
Blackbelly Racerunner~40%+20%
Common House Gecko~40%+10%
-
Bioparque Marcel Schaerer
Daily sight. prob.vs avg- Mantled Howler Monkey~90%≈
- Black Spiny-tailed Iguana~90%≈
- Giant Marine Toad~80%+20%
- Variegated Squirrel~70%+10%
White-nosed Coati~60%+10%
Central American White-faced Capuchin~60%+30%- Mexican Smilisca~60%+10%
Milk Frog~60%+30%- Green Iguana~50%-20%
Pacific Ridley~50%≈
Central American Lyresnake~50%+20%- Common House Gecko~50%+10%
-
North park edge
Daily sight. prob.vs avg- Black Spiny-tailed Iguana>90%+10%
- Giant Marine Toad~90%+30%
- Mantled Howler Monkey~80%≈
- Variegated Squirrel~70%≈
- Mexican Smilisca~70%+20%
- Rose-bellied Lizard~50%+10%
Rufous-backed Wren~50%-20%- Green Iguana~50%-20%
- Common House Gecko~50%+10%
- Pacific Ridley~40%≈
Dry Forest Toad~40%+20%
Black-headed Trogon~30%-20%
-
La Esperanza
Daily sight. prob.vs avg- Mantled Howler Monkey~90%+10%
- Black Spiny-tailed Iguana~90%+10%
- Variegated Squirrel~80%+10%
- White-nosed Coati~80%+30%
- Green Iguana~70%≈
- Rose-bellied Lizard~50%+10%
- Mexican Smilisca~50%≈
- Rufous-backed Wren~50%-20%
Great Kiskadee~40%-30%- Black Vulture~40%-30%
Hoffmann's Woodpecker~40%-20%
Great-tailed Grackle~40%-20%
🏕️ Experience
Essentials
Entrance
Paid
Tourism
Low
Typical stay
1–2
daysTrails
Moderate
World Heritage
No
Climate
Temp °C Rain mm
JanFebMarAprMayJunJulAugSepOctNovDec
0.0 Good
Wallace's Line Score
How good is this park for seeing wildlife? 🦜
Biodiversity
GoodHow rich is the wildlife?
3.5
Species by taxon
🦅 Birds 457
🐒 Mammals 166
🦎 Reptiles 82
🐸 Amphibians 22
727 Total Species
828 Global average across 316 parks
27 Threatened 62 Endemic
🔭
Sighting
Very goodHow likely to see animals?
3.6
🎯
Top-12 Avg Probability
67% 📊
Coverage (182 species at ≥5% of 727 in the inventory)
25% 🔀
Taxon variety in top 12 (7 bird, 2 reptile, 2 mammal, 1 amphibian)
80% 🔭
Species per 10 outings (distinct species a visitor would meet over 10 outings — effort held equal across parks)
109 🌟
Iconic-group species (≥15%) (every species from the 19 iconic groups — monkeys, cats, toucans, macaws, sloths, crocodilians… — not just the 4 highlighted above)
12 ⭐
High-prob species (>40%)
25 🏕️
Experience
Very goodHow easy and pleasant is the visit?
3.6
Climate Mixed Medium
Entrance Paid Low
Tourism Medium Medium
Trails Moderate Medium
World Heritage No —
What visitors say
During the four hours we saw an olive ridley as well as a green sea turtle (otherwise known as a black turtle in Costa Rica) which were trying to nest.
My group was incredibly lucky to see all 3 turtles spotted the first night of patrol and get to work on one within the first hour.
Wednesday night, we watched a video on sea turtles and egg harvesting at Ostional.
A few hours later, the numbers rose, and we found ourselves witnessing hundreds of Olive Ridley sea turtles crawling ashore was like nothing we’d ever seen.
Before you go
What animals can you see in Ostional Wildlife Refuge?
727 species
Ostional Wildlife Refuge has 727 recorded vertebrate species. The ones wildlife watchers report most often on a given day are Black Spiny-tailed Iguana (about 90%), Mantled Howler Monkey (about 80%), Black Vulture (about 80%), Great Kiskadee (about 70%) and Rufous-backed Wren (about 70%). Among amphibians, the most-seen is Giant Marine Toad (about 60%).
When is the best time to visit Ostional Wildlife Refuge for wildlife?
May and November
In those months the park's 12 most-seen species average about 70% on a given day, against about 60% in June–October and December–April.
Can you see a Pacific Ridley in Ostional Wildlife Refuge?
Yes
About 40% of wildlife watchers report a Pacific Ridley sighting in Ostional Wildlife Refuge on a given day, based on 157 verified sightings from GBIF citizen-science data from 2019 to 2026. The best time is July to September (about 60%).
Can you see a Mantled Howler Monkey in Ostional Wildlife Refuge?
Yes
About 80% of wildlife watchers report a Mantled Howler Monkey sighting in Ostional Wildlife Refuge on a given day, based on 265 verified sightings from GBIF citizen-science data from 2019 to 2026. The best time is January, April and June (about 90%).
Can you see a Black Spiny-tailed Iguana in Ostional Wildlife Refuge?
Yes
About 90% of wildlife watchers report a Black Spiny-tailed Iguana sighting in Ostional Wildlife Refuge on a given day, based on 308 verified sightings from GBIF citizen-science data from 2019 to 2026. The best time is July and August (about 90%).
Can you see a White-nosed Coati in Ostional Wildlife Refuge?
Yes
About 50% of wildlife watchers report a White-nosed Coati sighting in Ostional Wildlife Refuge on a given day, based on 62 verified sightings from GBIF citizen-science data from 2019 to 2026. The best time is April (about 80%).
Where in Ostional Wildlife Refuge is wildlife easiest to see?
Around Reserva Biológica Nosara (Lagarta)
The richest sighting zone is around Reserva Biológica Nosara (Lagarta), followed by Albergue y Camping Refugio de Tortugas and Bioparque Marcel Schaerer, ranked by how many of the park's headline animals visitors can expect to see in each. See the zones on the map.
Is Ostional Wildlife Refuge good for wildlife watching?
3.5 out of 5
On the Wallace's Line Score, Ostional Wildlife Refuge rates 3.5/5: 181st of 316 parks worldwide and 26th in Central America. 27 of its species are reported by about 40% or more of wildlife watchers on a given day.
