As temperatures drop, most creatures retreat to hunker down or hibernate.

What are crows saying when their loud cawing fills a dark winter’s evening? Despite the inescapable ruckus, nobody knows for sure. Birds congregate daily before and after sleep, and they make some noise, but what might be happening in those brains is a mystery.

Curious about these raucous exchanges, researchers at the University of Washington Bothell are listening in. They are placing equipment on the roof of their building — a meeting place for some of the thousands of crows that sleep in nearby campus trees — and using a sort of computerized eavesdropping to study the relationship between calls and the birds’ behavior.

Hundreds of marine turtles die every year after becoming entangled in rubbish in the oceans and on beaches,  including plastic ‘six pack’ holders and discarded fishing gear.  

Agriculture and domestic activities consume much of the Colorado River water that once flowed to the Colorado Delta and Northern Gulf of California. The nature and extent of impact of this fresh-water loss on the ecology and fisheries of the Colorado Delta and Gulf of California is controversial. A recent publication in the journal PeerJ reveals a previously unseen risk to the unique local biodiversity of the tidal portion of the Delta. 

Populations of cheetahs in southern Africa have declined as farming and other human activities push deeper into the free-roaming cats’ range, a new study co-led by Duke University doctoral student Varsha Vijay finds.

The Thomas Fire burning north of Los Angeles in Ventura County, California is now the state’s fifth-largest wildfire on record. Less than 15 percent contained and moving west quickly, the fire is being fueled by dry conditions and strong winds. It is one of five wildfirescurrently burning in southern California.

The federally endangered bird, the snail kite, was faced with an interesting dilemma: The island apple snail was good to eat, but about two to five times bigger than the native snail that the bird usually consumed. What’s a hungry bird to do? Evolve – quickly.

A study by a team of University of Florida researchers has found that in about 10 years, the snail kite has evolved to develop a larger beak as its new prey, the island apple snail, proliferated and became invasive. The study is published in Nature Ecology & Evolution.

A University of Central Florida biologist whose groundbreaking work tracking the movements of sea turtle yearlings in the North Atlantic Ocean attracted international attention has completed a similar study in the South Atlantic with surprising results.

Logging of the largest trees in the Sierra Nevada’s national forests ended in the early 1990s after agreements were struck to protect species’ habitat.

California Academy of Sciences team joins Malaysian colleagues to survey region’s rich biodiversity; data to support UNESCO nomination.