This September 1 is the 100th anniversary of a landmark event in the history of biodiversity. On that day in 1914, at about one o'clock in the afternoon, Martha - the last surviving passenger pigeon - died at the Cincinnati Zoo. It is extraordinary to know with virtual certainty the day and hour when a species ceases to be a living entity. And it was a stunning development because less than half a century earlier, the passenger pigeon had been the most abundant bird in North America, if not the world. As late as the 1860s, passenger pigeons had likely numbered in the billions, and their population was neither evenly distributed across the landscape nor in any way subtle. These birds had a propensity for forming huge aggregations that are difficult to imagine today. John James Audubon, America's best-known student of birds, recorded a flight of passenger pigeons along the Ohio River in Kentucky that eclipsed the sun for three days. Other accounts, written over the course of three centuries and in several languages, testify to the birds darkening the sky for hours at a time over the major cities of the eastern third of the United States and Canada.

Agricultural pests - viruses, bacteria, fungi, blights, mildews, rusts, beetles, nematodes, flies, mites, spiders and caterpillars - are spreading thanks to trade, travel and global warming, writes Tim Radford. The world faces a dire future of increased crop losses and growing insecurity. Coming soon to a farm near you: just about every possible type of pest that could take advantage of the ripening harvest in the nearby fields.

Until recently, little has been known about what genetic changes transform wild animals into domesticated ones. An international team of scientists, one of whom is a University of Montana assistant professor, has made a breakthrough by showing that genes controlling the development of the brain and the nervous system were particularly important for rabbit domestication. The study was published Aug. 28 in Science and gives answers to many genetic questions.

I can't help but smile when I see a puffin, and I know I'm not alone. Thousands of people board tour boats each summer in Maine to get a glimpse of these charming seabirds with their tuxedo plumage and rainbow beaks. But what's in those beaks is serious business. The forage fish that puffin parents bring back to their island nests mean the difference between life and death for the chicks, and the past few years offer stark evidence of what happens when those fish become scarce.

As monarch butterflies are beginning their epic migration from Canada and the U.S. to Mexico for the winter, concerns about the drastic rate at which they're disappearing from the landscape have led environmental and health organizations to petition the government for federal protection. This week, the Center for Biological Diversity, Center for Food Safety, Xerces Society and monarch scientist Dr. Lincoln Brower filed a legal petition with the U.S. Fish and Wildlife Service seeking protection for monarchs under the Endangered Species Act.

A yawn is defined as a reflex act of opening one's mouth and inhaling deeply. We yawn most often when we are tired or when we're bored. But we also always yawn when we see someone else doing it. Why? People say we can't help it - it's contagious! But what really triggers this involuntary tendency? According to studies, yawning when others do is a sign of empathy and a form of social bonding. And believe it or not, we're not the only species to exhibit these contagious behaviors. A new study published today in the journal PLOS ONE shows that wolves may also be susceptible to yawn contagion.

A new 'State of the World's Rivers' database shows how the world's rivers have been impoverished by dams and their ecosystems devastated - and provides a valuable resource to help save river basins that remain in good health. International Rivers has launched 'The State of the World's Rivers', an interactive online database that illustrates the role that dams have played in impoverishing the health of the world's river basins.

Ever wonder how lizards like Geckos can walk up walls and even across the ceiling? Is it sticky feet, anti-gravity, or what? Researchers at Oregon State University have developed a model that explains how geckos, as well as spiders and some insects, can run up and down walls, cling to ceilings, and seemingly defy gravity with such effortless grace. This ability, outlined today in the Journal of Applied Physics, is a remarkable mechanism in the toes of geckos that uses tiny, branched hairs called "seta" that can instantly turn their stickiness on and off, and even "unstick" their feet without using any energy.

Researchers in India say they have developed a prototype of an energy-harvesting device from the cocoons of a domesticated species of silk moth. They hope to put the technology to practical use while also tackling waste materials from the silk processing industry.

In Italy, a man foraging for mushrooms was attacked when he happened upon a mother bear and her cubs. Part of a reintroduction and conservation program in Italy's northern Dolomites, the bear, named Daniza, was ordered to be captured and possibly killed. This has sparked social media outrage, prompting those on twitter to hashtag #iostocondanzia (I'm with Danzia). The outrage stems from a revelation that when mauling victim Daniele Maturi happened upon the bear, he did not immediately leave, but rather hid behind a tree to watch him. It is said the bear only charged when it spotted him watching from behind a tree (like a predator would do, thus provoking the bear).