your science briefing for 02.05.2025

Why your cat is the planet's deadliest predator, how to get people to eat less meat, the tricky question of why Americans say they prefer urban sprawl, and more...

Cats are Earth’s perfect killers. Oh, this isn’t a setup to a joke, it’s the result of a study which found that outdoor cats are killing over 390 million animals per year in Australia alone. If they do bring a kill home, there are probably another five or six victims left in the wild. And that’s just the pet cats. Feral strays routinely kill more than three billion. Reptiles, birds, rodents, it doesn’t matter. They’re all in grave danger, so much so that researchers are pleading with you to please, for the good of the native fauna, lock up your fluffy, adorable little killing machine indoors… (University of Sydney)

Environmental activists and health advocates want people to eat less meat. The latter look at studies tying too much red meat to heart disease and gut cancers, and urge us to try more plant based alternatives. The former worry about the heavy tolls of factory farming, so much so they want to grow meat in labs. People, on the other hand, have little interest in giving up meat. Unless… the plant based alternatives are tasty, filling, and cost significantly less. Then, they’re a lot more open minded… (PhysOrg)

Let’s talk about you and me, let’s talk about sperm count baby. Or, more specifically, the worrying decline in sperm counts seen across the world. While one of the major reasons for falling fertility is the near total elimination of teen pregnancy in developed nations, the other may be industrial pollution and the impact of modern lifestyles full of stress and processed food instead of healthy diets and exercise on sperm counts, motility, and vigor… (New Scientist)

People whose life motto is “420 blaze it” or for whom “wake and bake” is a way of life aren’t exactly known for having terrific short term memory. As more and more states and nations legalize or turn a blind eye to cannabis products, researchers want to get a better understanding of not just its benefits, but also its risks. In the largest study to date, scientists found that smoking weed over a thousand times has a very real effect on working memory. So, if you need to really tax your brain to do something, maybe a little moderation is in order… (University of Colorado)

Americans claim that they slightly prefer suburban sprawl, but researchers wonder if the reason why is half a century of zoning for single family housing and furious NIMBY opposition to the very idea of walkability and density, and the fact that to living a more walkable neighborhoods is more expensive because they’re so rare compared to vast, sprawling suburban blah-scapes… (Yale Climate)