BACK (YARD) TO NATURE: As spring continues springing across the United States, millions of homeowners are enjoying watching a variety of wildlife bustle around their back yards again, from robins and rabbits to hummingbirds and herons. But for a select 128,000 U.S. back yards, the local wildlife isn't just nervously stopping in for a few bites of birdseed or leaves — it actually lives there, too. These homes are part of a program by the National Wildlife Federation that turns back yards into "Certified Wildlife Habitats," which must meet five basic needs of native wildlife to be certified: providing food, water, cover, a place to raise their young, and freedom from chemical treatments such as pesticides. While the program has been around for 37 years, its popularity has been surging in recent years, with enrollment growing by 400 percent since 2003. Doug Inkley, a senior NWF scientist, says backyard habitats are more important than ever due to encroaching development and shrinking natural habitats. "Many [species] have been in decline," he tells USA Today. "Providing a place for them is extremely educational, it provides good habitat, and it can be a safe endeavor." It's not necessarily always safe, however — if the habitat is inviting enough, a small gathering for local fauna could escalate into a neighborhood block party. "You should understand that you're not only going to attract songbirds and squirrels," says Clemson University wildlife ecologist Greg Yarrow, "but some wildlife that you may not be interested in, like a bear or raccoon or skunk." (Sources: USA Today, National Wildlife Federation)

OIL ON TROUBLED WATERS: As hopes fade for finding 11 offshore workers who disappeared in an oil-rig explosion Tuesday night, oil giant BP is scrambling to avert an environmental disaster after the damaged rig sank into the Gulf of Mexico Thursday. A one-by-five-mile oil slick quickly covered the area, and BP's vice president for Gulf of Mexico exploration said in a news conference that it "certainly has the potential to be a major spill." While 115 of the rig's workers survived Tuesday's explosion, 11 remain unaccounted for, spurring a search-and-rescue effort by the U.S. Coast Guard that entered its third day Friday morning. Coast Guard helicopters, planes and patrol boats have been scouring the rig's vicinity to no avail, and while the search continues, many survivors have said the 11 missing may have been near the site of the explosion when it occurred. "Based upon reports from crew members we met as they came in last night, at the time of the incident, they believe [the missing workers] may have been aboard the rig and not able to evacuate," says an official with Transocean Ltd., which leased the rig from BP. In addition to the missing workers and the surface oil slick, the sea-floor oil well itself is also a big concern, since there's no way to know yet whether oil is still spilling out of it. Plus, the sunken rig also contains 700,000 gallons of diesel fuel, and while there's no sign any of that has begun leaking out, Coast Guard Rear Adm. Mary Landry points out that "we don't know what's going on below the surface of the water." (Sources: Houston Chronicle, New York Times, Associated Press)

WHALE WARS: The International Whaling Commission proposed a controversial compromise on Thursday, offering to legalize commercial whaling in exchange for a cutback in the number of whales killed each year. Whaling was outlawed worldwide in 1986, but three countries — Japan, Norway and Iceland — took that more as a suggestion than a rule. The whale-hungry trio has been killing about 1,700 whales annually in recent years, and since they're ignoring the law anyway, the United States and other anti-whaling nations have been trying to strike a deal to allow some commercial whaling in hopes of bringing down the overall death count. Under the new proposal, gradually shrinking limits would be attached to certain whale species — 400 Antarctic minke whales could initially be killed each year, for example, while that number would drop to 200 over the next decade. "Some whaling will be the price to pay for the reduction in the number of whales killed," IWC Chairman Cristian Maquieira tells the Washington Post. "I don't think anybody will be happy with the numbers, but what I'm trying to achieve is a situation where everybody is willing to sit down at the table because they see something there that otherwise they would be unable to obtain." Critics argue the proposal amounts to a police force ceding defeat to criminals: "Saying you are opposed to commercial whaling, but supporting quotas to kill whales is disingenuous and merely political posturing towards Japan," says Greenpeace oceans campaigner Phil Kline. " It is also a less than auspicious way to mark the 40th anniversary of Earth Day." (Sources: Washington Post, BBC News, AP)

ENEMY MINE: Friday's New York Times takes an in-depth, five-page look at the coal-mine explosion that killed 29 West Virginia miners earlier this month, comparing the mine's embattled owner with another mining company that has a much cleaner safety record. Massey Energy, which runs the Upper Big Branch mine, has been plagued by safety violations and deadly accidents for years at various mines, but some of the pre-explosion warning signs at Upper Big Branch were especially dramatic. The mine has a longstanding problem with methane buildup, which had already required four evacuations this year alone, and rather than properly sealing an old coal shaft that let the gas into the mine, a former Massey foreman says workers used rags and garbage to create a makeshift sealant. The Times examines Massey's safety record in contrast with that of the TECO Coal Corporation, which has suffered just a fraction of Massey's disasters and infractions, and fosters a culture of openness that's a stark difference from Massey's famously insular style. At TECO's E3-1 mine in Kentucky, for example, there are fewer employees and higher methane levels than at Upper Big Branch, yet E3-1 hasn't had an underground fatality since it opened in 2004, and has nowhere near Upper Big Branch's number of safety violations. "The mine has to be ventilated," a TECO executive says. "Otherwise, it will destroy the company. I don't think TECO Coal could have an accident like Massey's and survive." (Source: New York Times)

FUNGUS AMONG US: A newly discovered type of airborne fungus has already killed several people in Oregon, and scientists are now worried it could spread outward into California and other nearby states. The fungus's mortality rate so far is about 25 percent out of 21 U.S. cases that have been analyzed, compared with a mortality rate of 8.7 percent among 218 cases north of the Canadian border. Cryptococcus gattii is related to the more common Cryptococcus neoformans (pictured), but is drastically more virulent and is spurring serious warnings from Duke University researchers who have been studying it. "This novel fungus is worrisome because it appears to be a threat to otherwise healthy people," says one of the researchers. "Typically, we see this fungal disease associated with transplant recipients and HIV-infected patients, but that is not what we are seeing." C. gatti symptoms may appear two or more months after exposure, and can include a cough that persists for weeks, sharp chest pains, shortness of breath, headache, fever, nighttime sweats and weight loss. In animals, it causes a runny nose, breathing trouble, nervous system problems and raised bumps under the skin. It can be treated but not prevented, since there's no vaccine. The Duke researchers are studying C. gatti along with its broader family tree in hopes of understanding how such aggressive fungi evolve. "We are trying to put together the evolutionary story of where these types come from by closely studying the genetics of all samples possible," says one of the project's research associates. (Source: e! Science News)

Russell McLendon

Want to receive the day's eco-news in your inbox? Click here to sign up for the Daily Briefing newsletter.

Photo (birds on birdfeeder): Rennett Stowe/Flickr

Photo (Deepwater Horizon oil-rig fire on April 21): ZUMA Press

Photo (humpback whale tail): National Oceanic and Atmospheric Administration

Photo (sign near Upper Big Branch coal mine in Montcoal, W.Va.): Jeff Gentner/AP

Photo (C. neoformans): U.S. Centers for Disease Control and Prevention

Russell McLendon ( @russmclendon ) writes about humans and other wildlife.