"Burmese pythons and other giant snakes imported as pets could endanger some of America's most important parks and wilderness areas if they are allowed to multiply, according to a report released on Tuesday."

"The government plans to aggressively sterilize wild horses and transplant thousands to new public preserves in the Midwest and East as a solution to the nearly 40-year-old problem of how to manage the exploding numbers of wild horses in the West, Interior Secretary Ken Salazar said Wednesday."

"Too many boats and technology that is too good mean that nations must cooperate to preserve tuna and other fish stocks."

"A government study found that a group of endangered beluga whales in Alaska is declining, raising concern that bolstered protection for the animals is not coming quickly enough."

"The Interior Department moved closer to establishing habitat protections for the polar bear yesterday by sending its proposed rule to the White House Office of Management and Budget for review."

"Twenty-six countries Friday issued a joint statement putting diplomatic pressure on Iceland to abandon whaling. Icelandic whalers have killed more than 200 whales so far since June, including endangered 125 fin whales and 79 smaller and more abundant minke whales."

"Here on the endlessly rolling and tussocky terrain of northwest Canada, where man has hunted caribou since the Stone Age, the vast antlered herds are fast growing thin. And it's not just here."

"Half a century after Pacific walruses began recovering from industrial-scale hunting, marine biologists are growing worried that they face a mounting threat from global warming."

"As kids, many of us come to see snakes as frightening, evil creatures. In some places, that ingrained fear has taken a toll on the snake population. ... Some folks ... are trying to improve one snake's image - before it disappears."

"More than 50 years after nearly being wiped out in eastern U.S. forests by a deadly imported fungus, the American chestnut may be on the comeback trail."