The boreal digging frog (''Kaloula borealis'') is a species of

microhylid The Microhylidae, commonly known as narrow-mouthed frogs, are a geographically widespread family (biology), family of frogs. The 683 species are in 63 genera and 11 subfamilies, which is the largest number of genera of any frog family. Evolution ...

, or "narrow-mouthed," frog found in

Northeast Asia Northeast Asia or Northeastern Asia is a geographical subregion of Asia; its northeastern landmass and islands are bounded by the Pacific Ocean. The term Northeast Asia was popularized during the 1930s by American historian and political scienti ...

. Its range covers much of central and northeastern China, the

Korean Peninsula Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republic o ...

, and Jeju Island. Adult boreal digging frogs are roughly 4.5 cm in length, round in shape with toad-like speckled skin.

Tadpole A tadpole is the larval stage in the biological life cycle of an amphibian. Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial. Tadpoles have some fish-like features that may not be found i ...

s are up to 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 South Korea, officially the Republic of Korea (ROK), is a country in East Asia, constituting the southern part of the Korea, Korean Peninsula and sharing a Korean Demilitarized Zone, land border with North Korea. Its western border is formed ...

. 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 The rainy season is the time of year when most of a region's average annual rainfall occurs. Rainy Season may also refer to: * ''Rainy Season'' (short story), a 1989 short horror story by Stephen King * "Rainy Season", a 2018 song by Monni * ''T ...

, 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.

References

{{Taxonbar, from=Q1071723 Kaloula Amphibians of China Amphibians of Korea Amphibians described in 1908