The various Ensatina salamanders of the Pacific coast all descended from a common ancestral population ... A well-studied example of a ring species is the salamander Ensatina escholtzii of ...

Fluctuations in population ... mutualistic species vary with the density of another mutualistic species (Holland et al. 2002, Thompson et al. 2006, Holland & DeAngelis 2010). For example, as ...

U.S. bird populations are experiencing alarming declines due to factors such as habitat loss and climate change, according to ...

The evidence is pieced together from details drawn from all over the world, but it adds up to a disturbing picture ... know that many more species are "living dead" -- populations so critically ...

Many US Bird Species Seen as Reaching Population 'Tipping Point' By Will ... and egrets that show some increases," Parr added. Some examples of common birds now in decline include the chimney ...