See our four favorite innovations this month

Sniffing out poachers

Texas hounds are revolutionizing anti-poaching work in South Africa. By some estimates, 4,000 rhinos were killed in the Kruger National Park area during the past decade; how many remain there is debated, with claims ranging from 5,000 to 9,000. Since May 2018, the hounds, raised by Texas rancher Joe Braman, have contributed to a 24 percent drop in rhino poaching in the park and a 54 percent increase in apprehensions of poachers, authorities say.

In the past, law enforcement teams that used individual lead dogs to track poachers on foot struggled to keep up. Staff at the Southern African Wildlife College, a training facility outside Kruger, were eager to test free-running dogs in the area. After visiting, Braman, a passionate houndman and part-time cop, offered to train a team of his own dogs back in Texas and ship them to South Africa. In live operations, the hounds, wearing GPS collars, track a poacher’s scent, with helicopters and rangers close behind. By charging and biting en masse, the dogs keep their quarry at bay, Braman says: “If a dog starts attacking you, the first thing you’re gonna do is throw the gun and climb a tree.” —Paul Steyn

Read more about the Texas hounds chasing down rhino poachers in South Africa.

A sparkling way to cut microplastics

All that glitters is not green: Most glitters are plastic based and take hundreds of years to break down. Enter Bioglitter, created with cellulose from eucalyptus trees. In nature, the glitter biodegrades into harmless specks, says the U.K. firm that makes it. —Annie Roth

A lab the size and cost of a stamp

Diagnosing patients’ ills often means sending samples to testing laboratories. For areas that lack such resources, Harvard’s George Whitesides has spent years developing a “lab” on a stamp-size filter paper square. When this low-cost, easy-to-use device absorbs a drop of blood or urine, dots of chemical reagent change color to indicate various conditions, such as an abundance of protein. —AR

Fine-tuned fish sense

Note the thin black stripe down this mackerel’s side. That’s the lateral line, part of a valuable system that reads water motion and pressure. Tiny sensors along the line, called neuromasts, allow fish to identify movement very precisely—helping them hunt prey, avoid obstacles, and swim in schools, even in the dark. —Theresa Machemer