Why fewer monarch butterflies are surviving their winter migration to Mexico…

Researchers in Oregon's Willamette Valley found young native fish thriving in ditches that fill with water during the winter months. The unrecognized habitat meant farmers had been inadvertently raising fish in their fields, in addition to their intended crops, for…

In a highly anticipated decision, the Interior Department on Wednesday declared the polar bear "threatened" under the Endangered Species Act because of shrinking Arctic ice due to global warming. Two analysts consider the impact of the decision.