CR

Stejneger's Button Frog

Cycloramphus stejnegeri

Unknown

Overview

Cycloramphus stejnegeri is a species of frog in the family Cycloramphidae. It is endemic to the Serra dos Órgãos in southeastern Brazil. The specific name stejnegeri honors Leonhard Stejneger, a Norwegian–American herpetologist and ornithologist. Common name Stejneger's button frog has been coined for this species.

Cycloramphus stejnegeri faces severe population decline primarily due to habitat destruction from urban expansion and agricultural conversion in Brazil's Atlantic Forest region. The species' extremely restricted range makes it particularly vulnerable to localized threats, with deforestation and infrastructure development fragmenting its remaining habitat. Water pollution from agricultural runoff and urban waste further degrades the stream environments essential for its reproduction.

Threat summary

Habitat

This critically endangered frog inhabits Atlantic Forest streams and adjacent riparian vegetation in southeastern Brazil. It requires clean, fast-flowing water with rocky substrates for breeding and forested areas with dense leaf litter for foraging.

Forest· major

Conservation measures underway

Species managementSpecies recoveryEx-situ conservation

Other threatened species in CYCLORAMPHIDAE

EN

Izecksohn's Button Frog

Cycloramphus izecksohni

Declining
CR

Carvalho's Button Frog

Cycloramphus heyeri

Declining
CR

Lutz's River Frog

Thoropa lutzi

Unknown
Brazilian Button FrogEN

Brazilian Button Frog

Cycloramphus brasiliensis

Declining

Frequently asked questions

Why is Stejneger's Button Frog classified as Critically Endangered?
Stejneger's Button Frog is classified as Critically Endangered — facing an extremely high risk of extinction in the wild — because population sizes are very small, declining sharply, or restricted to a tiny range. Cycloramphus stejnegeri faces severe population decline primarily due to habitat destruction from urban expansion and agricultural conversion in Brazil's Atlantic Forest region. The species' extremely restricted range makes it particularly vulnerable to localized threats, with deforestation and infrastructure development fragmenting its remaining habitat. Water pollution from agricultural runoff and urban waste further degrades the stream environments essential for its reproduction.
Where does Stejneger's Button Frog live?
Stejneger's Button Frog occurs in across multiple regions. Country-level distribution data is sourced from the IUCN Red List and cross-referenced with GBIF occurrences.
What are the main threats to Stejneger's Button Frog?
The main threats to Stejneger's Button Frog are 11.1, 8.1, 8.2, and ai-1. The full IUCN-classified threat record for this species is detailed on the species page.

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