Kaloula borealis
In 3 days ~30% in a week ~60%
The boreal digging frog (Kaloula borealis) is a species of microhylid, or "narrow-mouthed," frog found in Northeast Asia. Its range covers much of central and northeastern China, the Korean Peninsula, and Jeju Island. Adult boreal digging frogs are roughly 4.5 cm in length, round in shape with toad-like speckled skin. Tadpoles are up to 35 mm (1.4 in) in length.
The boreal digging frog is common across much of its range, but is listed as an "Endangered category II species" in South Korea. It inhabits cultivated fields, including rice paddies, and is often found in close proximity to humanity, at altitudes of 10 to 900 m.
Boreal digging frogs breed during the annual rainy season, around June and July. After the rainy season is over they dig burrows underground, emerging only at night to feed. The eggs are laid in batches of 15–20 in monsoonal pools, with the tadpoles maturing within 30 days, much faster than most other frogs in this area. Wikipedia →
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China · 2026
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China · 2025
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South Korea · 2026
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| # | Park | Country | Daily sighting probability |
|---|
More parks will be added in future updates.
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | Zoológico La Era de las aves | 🇪🇸 Spain |
With luck
About 10% of wildlife watchers report a Boreal Digging Frog sighting in Beijing on a given day, based on 74 verified sightings from GBIF citizen-science data. It is the 3rd most-seen of the 6 amphibians we can rate there. Over three days the chance rises to about 30%, and over a week to about 60%, if each day is a fresh chance.
July and August
In those months about 30% of wildlife watchers report a Boreal Digging Frog in Beijing on a given day, against under 5% in November to April, the lowest months. Those are among Beijing's wettest months, with about 130 mm of rain a month against almost none in January.
5th of 6
Of the 6 cities where we can rate Boreal Digging Frog sightings, Beijing ranks 5th at about 10%. The best odds are in Nanjing (China, about 20%), Daejeon (South Korea, about 20%) and Qingdao (China, about 20%).
Same order: Anura
The closest relatives of the Boreal Digging Frog that you can see in Beijing (order Anura, Frogs and Toads) are Asiatic Toad (about 30%), Black-spotted Frog (about 20%) and Oriental Fire-bellied Toad (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Boreal Digging Frog is recorded against all the amphibians logged in Beijing (74 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.
