by Russell McLendon, Mother Nature Network
Heidi, the cross-eyed opossum
2011 was the Year of the Rabbit, but it wasn't very lucky for this earless bunny, born near Japan's Fukushima Daiichi nuclear power plant in May. The plant has leaked large amounts of radiation after being damaged by the March 11 earthquake and tsunami, but it's unclear whether that caused this rabbit's mutation.
The disaster at Fukushima was one of the year's biggest news events, including its effects on local pets and wildlife. But lots of other big animal-related stories also unfolded over the past 12 months. We've collected 11 of the most intriguing ones here.
1. Beebe blackbirds
2011 got off to an eerie start, as a rash of mass animal deaths made global news in January. First came the demise of 4,000 red-winged blackbirds in Beebe, Ark. (pictured), followed days later by 500 blackbirds in Louisiana and up to 100 crows in Sweden. Meanwhile, millions of dead fish washed up in Maryland, and piles of dead crabs dotted beaches in the U.K.
The incidents weren't related, although several bird die-offs were attributed to panicked flying amid New Year's Eve fireworks. And while such events are rare, they're not unheard of - 1,500 grebes died in Utah on Dec. 12, for example, possibly disoriented by city lights.
2. Decorah eagles
The year may have started with bad news about birds, but thanks to the Iowa nonprofit Raptor Resource Project, it didn't stay that way. The RRP, which set up the Internet's first "birdcam" in 1998, enjoyed unprecedented popularity in early 2011 when its webcam feed of a bald eagle nest in Decorah, Iowa, went viral.
The pair of eagle parents in Decorah laid three eggs in February and March, and watched all three hatch in April. The trio of chicks then fledged in June. Along the way, more than 200 million people tuned in to watch online.
3. Knut the polar bear
Knut was arguably the most famous polar bear on Earth during his short life, which began on Dec. 5, 2006, and abruptly ended on March 19, 2011. He had been rejected by his mother shortly after birth, and was instead hand-reared at the Berlin Zoo by keeper Thomas Doerflein. While there, Knut became an international celebrity, reportedly earning millions for the zoo in merchandising and admissions. He even appeared on the cover of Vanity Fair in 2007.
A postmortem CAT scan concluded that Knut suffered an epileptic seizure, possibly due to encephelitis (although the cause of death was drowning, since he collapsed into his pool during the seizure). The zoo plans to build a monument, but its idea of stuffing Knut's body for display has been met with outrage by some fans.
[ Related: 13 bizarre animals of the Arctic ]
4. Heidi the opossum
Heidi had humble origins, found as an orphan in 2008 and taken to a North Carolina wildlife shelter with her sister, Naira. They were raised there until 2010, when Germany's Leipzig Zoo acquired them for a new exhibit. Both had eye problems, but Heidi was especially cross-eyed - and that would be her ticket to fame.
When the German press got its first glimpse of the "squinting opossum" in late 2010, a star was born. Heidi collected 300,000 Facebook fans, inspired YouTube tributes (see below) and even appeared on "Jimmy Kimmel Live!", where she correctly picked two of three Oscar winners.
Heidi died in September, but unlike Knut, her death wasn't premature. At 3.5 years old, she was considered elderly for a Virginia opossum, which only live to about 4 or 5.
5. Bronx Zoo cobra
For six days this spring, New York and the world were mesmerized by "Mia," an Egyptian cobra that escaped her enclosure at the Bronx Zoo. Egyptian cobras are poisonous, so the zoo closed its reptile house while hunting for the snake. Meanwhile, Mia earned an online fanbase thanks to a Twitter account detailing her fictitious antics. She had 200,000 followers within a week, and even an endorsement deal, but was finally found at the zoo on March 31.
Here are a few of @BronxZoosCobra's tweets:
• "City may not sleep, but I'm ready to. Ooh a chimney! I bet you bragged to your friends about having a working fireplace in NYC. Hi roomie."
• "If you see a bag of peanuts inexplicably moving along the ground at Yankee Stadium today. Just ignore it. It's probably nothing."
• "Leaving Wall Street. These guys make my skin crawl."
[ Related: Hairy Houdinis: 6 great animal escape artists ]
6. Military dogs
Dogs have a long history in the U.S. military, but they were especially prevalent in 2011. Perhaps the year's top canine soldier was the unidentified dog that joined Navy SEAL Team Six on its raid of Osama bin Laden's compound in May.
2011 also featured several other big stories about heroic dogs, including:
• Loyal dog 'Hawkeye' mourns fallen Navy SEAL
• Military dogs suffer from PTSD
• Navy dogs use titanium teeth, body armor
• Hero Dog Awards honor exceptional canines
[ Related: 6 green things the military is doing ]
7. Happy Feet the penguin
For the first time in 44 years, an emperor penguin showed up in New Zealand this June - about 2,500 miles away from home. The chick was clearly lost, trying to eat wet sand instead of snow for hydration. He was named "Happy Feet" after the 2006 movie about dancing penguins.
Officials were reluctant to intervene at first, but eventually heeded public calls to help. Happy Feet was taken to the Wellington Zoo, where vets removed several pounds of sand from his stomach and nursed him back to health. He was released to the wild in September, but his GPS tracker has been silent since Sept. 9. That could be bad news, or it could just mean the transmitter fell off underwater.
8. Cross-country cougar
In March 2011, the U.S. Fish and Wildlife Service declared the eastern cougar - aka mountain lion or puma - officially extinct. Three months later, a car struck and killed a cougar in Connecticut.
But as it turns out, the FWS wasn't exactly wrong. Based on DNA tests and other evidence, scientists realized it was actually a western cougar - one that had inexplicably wandered 1,500 miles across the country. Its genes matched the DNA of cougars in South Dakota, and photos from motion-sensing wildlife cameras revealed it had passed through Minnesota and Wisconsin in 2009 and 2010. It was Connecticut's first confirmed cougar in 100 years, although no one is sure why it embarked on such a long, lonely journey.
9. Willow the cat
Cougars aren't the only cats capable of slinking across America. A housecat named Willow completed an even longer trek in September, showing up in New York City five years after she vanished from her family's home in Colorado, which is about 1,800 miles away. Unlike the cougar, though, Willow likely had help.
"The cat was in very good condition, clean, a little chunky," a spokesman for Animal Care & Control of New York told Reuters. "So obviously someone was taking care of her." Still, if Willow can make it in New York - not to mention to New York - surely she can make it anywhere.
[ Related: 10 cats made famous by YouTube ]
10. Exotic animals in Ohio
When 56 exotic animals escaped from a private zoo in Ohio this October, it was like Noah's Ark had shipwrecked in the Buckeye State. The escapees included two wolves, eight bears, 17 lions and 18 tigers, all of which were kept in subpar conditions at the zoo by 62-year-old Terry Thompson, who apparently committed suicide. Thompson was found dead at his home on Oct. 18 with many of the animals' cages left open.
Police spent days tracking down all the animals, and ended up killing 49 of them for fear of public safety. Ohio is known for its lax pet laws, but in November a task force advised the state to ban the sale and ownership of exotic animals.
11. Great ape escape
Medical research on chimpanzees is losing favor around the world, as seen most recently when the U.S. agreed to limit the use of chimps in medical studies. And when a group of chimps were released by a research lab in Austria earlier this year - marking the first time some had been outdoors in 30 years - they drew an outpouring of sympathy from the Internet.
The liberated chimps were taken to an animal sanctuary near Salzburg, where German TV station RTL filmed them timidly marveling at their new surroundings. "They hugged, they laughed," the sanctuary's founder told RTL. "Imagine, one is 30 years imprisoned in an elevator, and then suddenly the door opens."
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