What Makes Salamanders Face Higher Extinction Risk? Key Findings and Conservation Priorities

The second Global Amphibian Assessment (GAA2) found that among amphibians, Caudata (salamanders) is a highly threatened taxonomic group when compared with Anura and Gymnophiona. Estimates suggest that half of the more than 800 known extant salamander species are threatened. At least ~60% (457 species) of salamanders are experiencing population declines, indicating that the number of threatened species will probably continue to rise. Compared with 1980–2004, the rate of decline in salamanders has increased from 2004 to 2022 — evidence that current untargeted conservation measures are inadequate and ineffective for the conservation of salamanders.

What drives salamander extinction risk and population decline?

Processes underlying species declines are complex, and extinction risk is not equal among species. Both species traits and extrinsic factors influence the degree of threat a species faces. Understanding the key ecological characteristics and extrinsic factors associated with increased extinction risk is therefore crucial to preventing population decline and species loss through adequate management and conservation strategies.

The GAA2 assessed 8,011 amphibian species, including 759 species from nine families in the order Caudata. Using this global dataset, we compiled 7 intrinsic and 11 extrinsic variables from published literature and conducted the first systematic comparative analysis of salamander extinction risk. We analyzed 711 species (excluding 45 Data Deficient species and 3 Extinct species) worldwide to disentangle how species traits, climate, and human threats drive extinction risk and population decline. Our findings can help advance scientific understanding and support prioritized conservation actions for salamanders.

Key findings

Pattern of salamander extinction risk

According to the 2025 IUCN Red List:

• 217 species (28.59%) — Least Concern (LC)
• 68 species (8.96%) — Near Threatened (NT)
• 109 species (14.36%) — Vulnerable (VU)
• 184 species (24.24%) — Endangered (EN)
• 133 species (17.52%) — Critically Endangered (CR)
• 3 species (0.39%) — Extinct (EX)
• 45 species (5.93%) — Data Deficient (DD)

Overall, 429 species (56.52%) are threatened, making salamanders one of the most threatened vertebrate groups.

Nonrandom extinction risk across salamander families

Threatened salamanders are not evenly distributed among taxonomic families. Two families are clearly identified as the highest-risk groups:

• Cryptobranchidae (giant salamanders): all species are threatened
• Hynobiidae (Asian salamanders): more than 72% of species are threatened

These ancient, unique lineages are highly sensitive to habitat loss, overharvesting, and environmental change due to their specialized biological traits. Their extinction would mean the permanent loss of entire branches of salamander evolutionary history. In contrast, families such as Rhyacotritonidae and Amphiumidae show much lower extinction risk, largely because they benefit from strong legal protection and relatively stable habitats.

Key drivers of salamander extinction risk

We identified the strongest predictors of extinction risk in salamanders:

• Small geographic range size
• Terrestrial breeding strategy
• Occurrence at higher minimum elevations
• High human threat intensity
• Low protected area coverage
• Climatic stress — high temperatures and drought

Salamanders with terrestrial breeding are especially vulnerable. Their eggs and larvae lack the buffer of water and are highly sensitive to warming and drying. High-elevation species face a "hidden trap": as temperatures rise, they cannot move upward to find suitable conditions and become trapped in their native habitats.

Key drivers of salamander population declines

Human threat intensity is the strongest predictor of both extinction risk and population decline. Rising temperatures and intensifying drought directly trigger rapid population collapses. However, geographic range size has opposite effects on extinction risk and population decline:

• Small-ranged species: higher extinction risk
• Large-ranged species: higher risk of local population decline

This result reveals distinct mechanisms between species-level extinction and population-level decline. Small-ranged species face higher extinction risk due to strong habitat specialization, low abundance, and poor recovery ability, making them sensitive to environmental change. In contrast, wide-ranging species have lower global extinction risk but suffer more local declines — a pattern driven by larger body size, lower population density, stronger human pressure, and cross-border management inconsistency. This means salamander conservation requires action at both global and local scales.

Risk assessment for Data Deficient species

We integrated family-level extinction risk and species-level probability estimates to assess extinction risk in data-deficient salamanders, following Senior et al. (2022) and Chen et al. (2025). We identified 22 high-risk DD species that belong to high- or medium-risk families and have a predicted threat probability above 0.75.

Predicted high-risk Data Deficient salamanders identified by Wang et al. (2026).

Most of these species have small ranges, low population densities, occurrence at higher elevations, or face multiple threats including habitat loss, pollution, and climate change. Our results help identify potentially threatened but data-deficient species and support re-evaluation of their conservation status.

Conservation priorities

Priority 1 — Focus on the highest-risk families. Target Cryptobranchidae and Hynobiidae immediately, especially endemic species in China and across Asia. These evolutionarily distinct lineages face the most urgent extinction risk.

Priority 2 — Protect small-ranged, high-elevation, terrestrial-breeding salamanders. These species are most sensitive to climate and habitat loss. Actions needed:

• Expand protected area coverage
• Restore habitat connectivity and reduce fragmentation
• Monitor microclimate moisture and temperature over time

Priority 3 — Reduce local human threats. Human threat intensity is the strongest driver. Core actions:

• Strictly enforce bans on illegal harvest for food, traditional medicine, and the pet trade
• Control habitat destruction and water pollution
• Restore wetland and forest habitats

Priority 4 — Improve protected area effectiveness. Salamanders with low protected area coverage are significantly more likely to decline.

• Strengthen management in existing protected areas
• Create or protect ecological corridors to allow movement under climate change

Priority 5 — Adapt conservation for climate change. Drought and warming directly drive declines. Strategies must include:

• Identify and protect climate refugia (moist habitats)
• Consider assisted colonization for "trapped" high-elevation species
• Develop captive breeding programs for critically endangered species

Conclusion

Salamanders are facing an extinction crisis, but we now have the scientific evidence to act more precisely and effectively. Their extinction risk and population declines are driven by a combination of species traits, climate change, and human activity. By focusing on high-risk families, protecting small-ranged species, safeguarding high-elevation habitats, and reducing human pressures, we can prevent further salamander extinctions.

The underlying study

The findings summarized here come from Wang et al. (2026), "Relative importance of traits, climate, and threats to extinction risk in salamanders," published in Conservation Biology — also listed in this issue's From the journals section.