A U.S. law from the pick-and-shovel days of the Western frontier now threatens natural treasures including Grand Canyon National Park as mining claims on public lands proliferate, an environmental group said on Friday. The 1872 Mining Law, signed by President Ulysses S. Grant, allows mining companies — including foreign-owned ones — to take about $1 billion a year in gold and other metals from public lands without paying a royalty, according to a report by the nonprofit Pew Environment Group. “The law was enacted … to encourage the development of the West and … rewarded those people who trekked across the frontier and gave them the right to mine gold, silver, whatever other valuable metals they could find on public land in unlimited amounts for free,” said Pew’s Jane Danowitz.

Two of the most well-known penguin species in Antarctica — chinstraps and Adelies — are under pressure because a warmer climate has cut deeply into their main food source, shrimp-like creatures called krill. Fewer of the juvenile penguins survive what scientists call their “transition to independence” because there isn’t enough krill to go around, according to a study published on Monday in the Proceedings of the National Academic of Sciences. The study found only 10 percent of young penguins survive the first independent trip back to their colonies from their winter habitat, said lead author Wayne Trivelpiece, a sea bird expert at the National Oceanic and Atmospheric Administration’s Antarctic Ecosystem Research Division. When the study began, back in the mid-1970s, the chances that a two-to-four-year-old penguin would survive the trip was about 50 percent, Trivelpiece said in a telephone interview.