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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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environment
To Encourage Responsible Trash Disposal, a Startup in Nigeria Pays People for their Waste
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Nigeria is home to more than 180 million people, who produce more than 32 million tons of waste per year and just 20 to 30 percent of this garbage is collected, according to one estimate. To provide Nigerians with incentive to dispose of their trash responsibly, Junks, a Nigerian waste management startup, provides people with the chance to exchange their trash for cash, according to Konbini.

The company offers to pay for items and materials like discarded electronics, glass, plastic, aluminum, books, and clothes. Once purchased, these materials are re-sold to wholesalers and recycling companies, according to Techpoint. Potential users who want to sell their trash are required to register on the startup's website, Junks.ng, and fill out a form with a description of the trash they're selling, along with their asking price and contact information. Once this information is received, representatives from Junks are sent to pick up and pay for the waste.

Computer programmer Bradley Yarrow founded Junks.ng in August 2017. Based in Port Harcourt, the capital of Rivers State, Nigeria, the company currently has just three employees, in addition to Yarrow. That said, the tiny startup appears to be doing big business, judging from a growing list of sold junk—which includes laminating machines, old laptops, and scrap car parts—already listed on Junks.ng.

[h/t Konbini]

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architecture
High-Tech Skyscrapers Could be Built with Low-Tech Wood
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When we think of wood construction, we often think of log cabins, tree houses, or the framework of residential properties. But if a new start-up has its way, we might soon be gazing up at 12-story buildings made almost entirely out of Douglas firs.

In a report for CityLab, journalist Amanda Kolson Hurley profiled Portland, Oregon's Lever Architecture, a firm attempting to revitalize wood-based towers that reduce the carbon footprints of conventional buildings. Their offices are located in a four-story property made from wood; their next major project, titled Framework, is expected to be 12 stories and slated to debut in Portland in 2019.

Part of Lever’s goal is to reduce concerns over wooden structures—namely, that they’re prone to fire hazards or might not be structurally sound in an earthquake. Developers use a building material called mass timber, a special type of strengthened wood in which timber panels are glued together to make beams and cross-set layers for walls and floors. Fire tests have shown the mass timber doesn’t ignite easily: It chars, which can insulate the rest of the panel from the heat. Strength testing has shown the layers aren’t easily jostled by outside forces.

Lever’s architects hope that wooden buildings will lessen the environmental impact of commercial towers that use concrete and steel, which are responsible for 10 percent of greenhouse gas emissions during their manufacturing.

Other firms have designs on taller buildings, including one 35-story tower in Paris and a 24-story building in Vienna.

[h/t CityLab]

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