Leptodactylus knudseni
Silhouette: Jose Carlos Arenas-Monroy · PhyloPic
In 3 days ~40% in a week ~70%
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 →
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French Guiana · 2024
© Arnaud Aury · XC952394 · CC BY-NC-SA 4.0
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Brazil · 1985
© M.S. Hoogmoed · XC882800 · CC BY 4.0
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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 |
Possible
About 20% of wildlife watchers report a Knudsen's Thin-toed Frog sighting in Manaus on a given day, based on 10 verified sightings from GBIF citizen-science data. It is the 3rd most-seen of the 7 amphibians we can rate there. Over three days the chance rises to about 40%, and over a week to about 70%, if each day is a fresh chance.
September
In that month about 40% of wildlife watchers report a Knudsen's Thin-toed Frog in Manaus on a given day, against under 5% in January, March, May–August and October–November, the lowest months. That is one of Manaus's driest months, with about 70 mm of rain against 270 mm in March.
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.
Only Manaus, in our data
Manaus is the only city on Wallace's Line with enough records to rate Knudsen's Thin-toed Frog sightings: about 20% of wildlife watchers there report one on a given day.
GBIF citizen-science records
It is estimated from how often the Knudsen's Thin-toed Frog is recorded against all the amphibians logged in Manaus (10 verified sightings), 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.
