Male tropical túngara frogs have evolved masses on their vocal cords that help them woo females with complex calls, show scientists working at the Smithsonian Tropical Research Institute (STRI) in Panama.

Better models of tropical forest dynamics are urgently needed to improve global change predictions. In hopes of modeling growth, mortality and size distributions of tropical trees, Helene Muller-Landau, University of Minnesota and colleagues from the Smithsonian's Center for Tropical Forest Science (CTFS) tested predictions based on the theory of metabolic ecology with data collected from tropical forests worldwide. The results -- no good fit and improved alternative models -- are published in two articles in Blackwell's Ecology Letters.

Deforestation and habitat loss are expected to lead to an extinction crisis among tropical forest species. Humans in rural settings contribute most to deforestation of extant tropical forests. However, "Trends such as slowing population growth and intense urbanization give reason to hope that deforestation will slow, regeneration will accelerate, and mass extinction of tropical forest species will be avoided," report S.J. Wright, Smithsonian Tropical Research Institute and H.C. Muller-Landau, University of Minnesota, in Biotropica online.