Leptodactylus knudseni
Silhouette: Jose Carlos Arenas-Monroy · PhyloPic
In 3 days ~80% in a week >90%
Leptodactylus knudseni, known commonly as Knudsen's frog, is a species of frog in the family Leptodactylidae. It is found in the greater Amazon basin. The first description of the species was published by W. Ronald Heyer in 1972.
The specific name, knudseni, is in honor of Jens W. Knudsen, who Heyer called "the most important influence in my decision to become a professional biologist" and said "continues to encourage my research efforts." The holotype was a juvenile female, with Heyer stating that he found the frog so distinctive that he preferred to describe it immediately rather than waiting for an adult specimen. It was collected from a decaying log in August 1970 by Heyer and Keith A. Berven, at an elevation of 260 m (850 ft), in Napo, Ecuador.
Usual adult snout–vent lengths range between 94–170 mm (3.7–6.7 in) for males and 102.7–154 mm (4.04–6.06 in) for females. They have smooth bodies and wide heads, are orange-brown or greenish on top and have a white belly. They have triangular dark markings on their lips, light-colored lines above the lips, black lines from the nose going over each eye, markings between the eyes.The iris of... Wikipedia →
Recording0:14
French Guiana · 2024
© Arnaud Aury · XC952394 · CC BY-NC-SA 4.0
Recording0:51
Brazil · 1985
© M.S. Hoogmoed · XC882800 · CC BY 4.0
Recording0:18
Guyana · 2026
© Paul Prior · iNaturalist · CC BY 4.0
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Brownsberg Nature Park | 🇸🇷 Suriname | |
| 2 | Tambopata National Reserve | 🇵🇪 Peru | |
| 3 | Manu National Park | 🇵🇪 Peru |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Manaus | 🇧🇷 Brazil |
Likely
About 50% of wildlife watchers report a Knudsen's Thin-toed Frog sighting in Brownsberg Nature Park on a given day, based on 13 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 8th most-seen of the 18 amphibians we can rate there. Over three days the chance rises to about 80%, and over a week to over 90%, if each day is a fresh chance.
December
In that month about 70% of wildlife watchers report a Knudsen's Thin-toed Frog in Brownsberg Nature Park on a given day, against about 10% in July and October, the lowest months. June and August–September have too few records to rate.
Between 7 and 10 pm
Across all the parks we cover, that three-hour window holds the most Knudsen's Thin-toed Frog sightings with a recorded time, and about 9 in 10 of them come between 6 pm and 6 am: it is mostly seen at night.
Yes
Of the 3 parks where we can rate Knudsen's Thin-toed Frog sightings, Brownsberg Nature Park has the highest daily chance: about 50%. Next come Tambopata National Reserve (Peru, about 20%) and Manu National Park (Peru, about 10%).
Same genus: Leptodactylus
The closest relatives of the Knudsen's Thin-toed Frog that you can see in Brownsberg Nature Park (genus Leptodactylus, Neotropical Grass Frogs) are Guiana White-lipped Frog (about 40%), Loreto White-lipped Frog (about 40%) and Smoky Jungle Frog (about 40%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Knudsen's Thin-toed Frog is recorded against all the amphibians logged in Brownsberg Nature Park (13 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.
