Thousands of scientists around the world sign a statement that warns the existence of 1,500 species will be imperiled if President Donald Trump’s wall is erected.

Researchers froze the fertilized eggs, taken from southern white rhinos, in hopes of preserving the near-extinct northern subspecies.

Assessments of species vulnerability provide crucial information for conservation efforts. But the science behind them is still evolving.

From the difficulty of tracking rare populations to the danger of poachers exploiting distribution data, the complications of studying endangered species require creative solutions from researchers.

To calculate the likelihood that organisms will be harmed by climate change, researchers estimate their exposure, sensitivity, and ability to adapt to new conditions.

Numbers of the wildcat, greater mouse-eared bat, and black rat have critically fallen in the U.K.  

Nutrient-rich water helped marine organisms reinhabit Chicxulub crater relatively quickly after the mass-extinction event.

A mass extinction event from an asteroid hitting Earth wiped out forests and, concurrently, tree-dwelling birds.  

The Chinese giant salamander is not one but five different species.