Homeland Security Secretary Janet Napolitano and Attorney General Eric Holder visit Mexico Thursday to meet with their counterparts.
Hillary Clinton arrives Wednesday with a new border security plan that signals greater cooperation between the two countries.
As lethal fungus spreads, captive amphibians are bred for eventual return to the wild.
It is bringing the technologies of tropical farming to other parts of Latin America, and to Africa and Asia.
Bolivia, Ecuador, and Venezuela push back on US operations.
More colleges are offering menus made from local foods.