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By the Numbers: The Billions of Animals Killed by Cats

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By Chris Gayomali/The Week

The internet loves cats. And why not? They're cute, endlessly entertaining and, unlike dogs, don't require constant attention. But what do cats do when they're not curling up in your lap? According to biologists, they're off killing other animals — billions of 'em. Scientists from the Smithsonian Conservation Biology Institute and the Fish and Wildlife Service estimate that each year, apparently bloodthirsty felines are preying on billions of birds and small mammals like indigenous chipmunks, shrews, and meadow voles. "When we ran the model, we didn't know what to expect," researcher Dr. Peter Marra told the New York Times. "We were absolutely stunned by the results." The model, which crunches numbers from 21 existing studies, is the first of its kind in the United States, and follows on the heels of a controversial plan in New Zealand to eliminate the nation's cats. Here's a look at our killer cats, by the numbers:

84 million

House cats in the United States

4 to 18

Birds killed by a typical house cat every year

8 to 21

Small mammals killed by a typical house cat every year

30 million to 80 million

Free-roaming, feral cats estimated to be living in the United States. They either survive alone or live in colonies. In Washington, D.C., for example, there are estimated to be some 300 outdoor cat colonies.

23 to 46

Birds killed by each feral cat every year

129 to 338

Small mammals killed by each feral cat every year

1.4 billion to 3.7 billion

Total birds killed by America's cats every year

15

Percentage of all bird deaths estimated to come at the hands — er, paws — of cats

6.9 billion to 20.7 billion

Total small mammals killed by cats every year

2 to 4

Factor by which these newly estimated kill rates are higher than mortality figures previously suggested. "Our findings suggest that free-ranging cats cause substantially greater wildlife mortality than previously thought and are likely the single greatest source of anthropogenic mortality for U.S. birds and mammals," the study's authors conclude. "Scientifically sound conservation and policy intervention is needed to reduce this impact."

Sources: LiveScience, New York TimesUSA Today

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London's Sewer-Blocking 'Fatbergs' Are Going to Be Turned Into Biodiesel
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UK officials can't exactly transform the Whitechapel fatberg—a 143-ton trash mass lurking in London's sewer system—into treasure, but they can turn it into fuel. As The Guardian reports, Scottish biodiesel producer Argent Energy plans to convert parts of the noxious blockage into an environmentally friendly energy source.

For the uninitiated, fatbergs (which get their names from a portmanteau of "fat" and "icebergs") are giant, solid blobs of congealed fat, oil, grease, wet wipes, and sanitary products. They form in sewers when people dump cooking byproducts down drains, or in oceans when ships release waste products like palm oil. These sticky substances combine with floating litter to form what could be described as garbage heaps on steroids.

Fatbergs wash up on beaches, muck up city infrastructures, and are sometimes even removed with cranes from sewer pipes as a last resort. Few—if any—fatbergs, however, appear to be as potentially lethal as the one workers recently discovered under London's Whitechapel neighborhood. In a news release, private utility company Thames Water described the toxic mass as "one of the largest ever found, with the extreme rock-solid mass of wet wipes, nappies, fat and oil weighing the same as 11 double-decker buses."

Ick factor aside, the Whitechapel fatberg currently blocks a stretch of Victorian sewer more than twice the length of two fields from London's Wembley Stadium. Engineers with jet hoses are working seven days a week to break up the fatberg before sucking it out with tankers. But even with high-pressure streams, the job is still akin to "trying to break up concrete," says Matt Rimmer, Thames Water's head of waste networks.

The project is slated to end in October. But instead of simply disposing of the Whitechapel fatberg, officials want to make use of it. Argent Energy—which has in the past relied on sources like rancid mayonnaise and old soup stock—plans to process fatberg sludge into more than 2600 gallons of biodiesel, creating "enough environmentally friendly energy to power 350 double-decker Routemaster buses for a day," according to Thames Water.

"Even though they are our worst enemy, and we want them dead completely, bringing fatbergs back to life when we do find them in the form of biodiesel is a far better solution for everyone," said company official Alex Saunders.

In addition to powering buses, the Whitechapel fatberg may also become an unlikely cultural touchstone: The Museum of London is working with Thames Water to acquire a chunk of the fatberg, according to BBC News. The waste exhibit will represent just one of the many challenges facing cities, and remind visitors that they are ultimately responsible for the fatberg phenomenon.

"When it comes to preventing fatbergs, everyone has a role to play," Rimmer says. "Yes, a lot of the fat comes from food outlets, but the wipes and sanitary items are far more likely to be from domestic properties. The sewers are not an abyss for household rubbish."

[h/t The Guardian]

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Great Britain's Last Snow Patch Is About to Disappear Completely for the First Time in a Decade

Until recently, it was easy to find snow in Great Britain at any time of the year—you just had to know where to look. In previous Septembers, the island has been home to as many as 678 snow patches, residual pockets of snow and ice whose climates and topographies keep them frozen through the summer. This year, though, only two of Britain's snow patches have survived the summer. And the island is now on track to be completely snowless by the end of the season, Atlas Obscura reports.

Snow patches vary in size and durability, with some melting completely by late summer and others remaining a permanent fixture of the landscape. Garbh Choire Mor—a steep glacial depression on top of Scotland's third-highest mountain, Braeriach—contains two of the oldest snow patches in Britain, known as the Pinnacles and the Sphinx. The Pinnacles snow patch dissolved into a puddle earlier this month, and the Sphinx snow patch, the last surviving snow patch in Great Britain, is expected to do the same in the next few days.

Scotland experienced uncharacteristically hot weather this summer, with temperatures creeping into the low 90s as early as May. But more significant than the sweltering summer was the dry winter that preceded it. Below-average snowfall last year meant this year's snow patches were already smaller than usual when temperatures started heating up. If the Sphinx snow patch does vanish before winter arrives, it will mark the first time in over a decade and just the sixth time in the last 300 years that England, Scotland, and Wales are without a single patch of snow.

The Sphinx snow patch, though currently a measly version of its previous self, is still visible for now. But Iain Cameron, a veteran "snow patcher" who writes an annual report on snow for the UK's Royal Meteorological Society, says it could be gone as soon as Wednesday, September 20.

He's currently camped out on Garbh Choire Mor, waiting to document the patch's final moments. You can follow his updates on Twitter.

[h/t Atlas Obscura]

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