AmphibiaWeb provides information on amphibian declines, natural history, conservation, and taxonomy.

Species of the Week
Telmatobius marmoratus | Marbled Water Frog

Amphibian News
Do steep thermal gradients limit dispersal and promote species diversification? In his classic “mountains are higher in the tropics” hypothesis, Janzen proposed that dispersal across mountain passes should be more arduous for tropical organisms exposed to reduced temperature seasonality than for temperate organisms. Zuloaga and Kerr (2016) adapted this prediction and examined whether temperature overlap between sites located at both sides of mountains ranges was associated with differences in amphibian assemblages. Although sites with low thermal overlap were generally associated with high species turnover, particularly in the tropical Andes, the study also found low thermal overlap across mountains of North America around 60º N, where amphibian assemblages are much less diverse and species turnover is low. These findings are likely conservative, because dozens of new high-elevation tropical amphibians are described every year, reinforcing the study’s conclusion that additional factors, in addition to the strength of thermal barriers, must play important roles in amphibian diversification across mountain ranges.

Current number of amphibian species: 7,667 (May 25, 2017) Newly added species