Hydrophylax gracilis
Silhouette: Michael Scroggie, from original photograph by John Bettaso, USFWS (original photograph in public domain). · PhyloPic
In 3 days ~60% in a week ~90%
Hydrophylax gracilis, also known as Gravenhorst's frog, Gravenhorst's golden-backed frog, and Sri Lanka wood frog, is a species of frog in the family Ranidae. It is endemic to Sri Lanka. Hydrophylax gracilis occurs in marshes, agricultural land, grassland, and bush forests at elevations below 600 m (2,000 ft). Adult frogs are semi-arboreal and semi-aquatic, whereas the tadpoles live in stagnant waters. H. gracilis is a common species that can be threatened by loss of its wetland habitats through wetland reclamation, urbanization, and aquatic agrochemical pollution. However, it is present in many protected areas. Wikipedia →
Recording0:37
Sri Lanka · 2026
© Deshan Dewmina · iNaturalist · CC BY-NC 4.0
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Sinharaja Forest Reserve | 🇱🇰 Sri Lanka | |
| 2 | Minneriya National Park | 🇱🇰 Sri Lanka |
Possible
About 30% of wildlife watchers report a Sri Lanka wood frog sighting in Sinharaja Forest Reserve on a given day, based on 15 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 10th most-seen of the 25 amphibians we can rate there. Over three days the chance rises to about 60%, and over a week to about 90%, if each day is a fresh chance.
August
In that month about 40% of wildlife watchers report a Sri Lanka wood frog in Sinharaja Forest Reserve on a given day, against under 5% in May–July, September and November, the lowest months.
Between 2 and 5 pm
Across all the parks we cover, that three-hour window holds the most Sri Lanka wood frog sightings with a recorded time, and about 7 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Yes
Of the 2 parks where we can rate Sri Lanka wood frog sightings, Sinharaja Forest Reserve has the highest daily chance: about 30%. Next come Minneriya National Park (Sri Lanka, about 20%).
GBIF citizen-science records
It is estimated from how often the Sri Lanka wood frog is recorded against all the amphibians logged in Sinharaja Forest Reserve (15 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
