Six months after announcing that it would phase out antibiotics from the birds its chicken meat comes from, McDonald’s is making big changes on the egg side of its poultry supply chain: The chain is going cage-free. The change will take 10 years to complete and will apply to the U.S. and Canadian…

Female killer whales live long after they can no longer have children because their accumulated wisdom can be vital for their relatives’ survival. Previous studies have shown post-reproductive age females greatly increased their children and grandchildren’s life expectancy, but it was not known…