Seabirds in the North Pacific eat more squid than they did a century ago, a change of diet that has helped them maintain their willowy figures despite changes in the ocean ecosystem and humans’ steady depletion of their fishing grounds, a Monterey Bay Aquarium study found.

A chemical analysis of the feathers of eight seabird species — collected in museums over the past 127 years — determined that the avians had feasted on heartier fish in the late 19th century, but began settling for squid and other creatures lower in the food chain to cope with ecosystem shifts over the decades. Read more.

Three thousand years ago, dense old-growth rainforests covered most of central Africa. But around 2,600 years ago, an event that ecologists call the Late Holocene Rainforest Crisis occurred, and the forests suddenly gave way to savannas dotted with islands of trees. Six hundred years later, the forests grew back almost as swiftly as they had vanished. Read more.

Methane gas is the most important greenhouse gas that may affect climate change after carbon dioxide. Livestock production is a significant source of methane gas emissions and climate effects worldwide. However, the impact of methane emissions from dairy and beef production in the U.S. is far more limited. According to EPA's most recent summaries, methane emissions from livestock production in the U.S. are about 2.5 percent of the total greenhouse gas emissions. About 8 percent of total greenhouse gas emissions in the U.S. come from agriculture, and the other 92 percent are from production and use of fossil fuel. Read more.