Veterinarians in Chile have found an unlikely fix for injured penguins: snug red vests woven with copper and zinc thread — the same wound-care fabric already used to treat cats and dogs.

  • 63% drop in active Humboldt penguin nests recorded across major breeding colonies between recent surveys three years apart
  • Two metals do the work: copper and zinc, woven directly into the fabric
  • First fitted and tested at Buin Zoo, on the outskirts of Santiago
  • Humboldt penguins are officially listed as a vulnerable species

Humboldt penguins are named for the cold Pacific current that runs along Chile and Peru, the only places they breed in the wild. Chile holds the largest concentration of the species, spread across a handful of protected coastal colonies — which makes conditions there a bellwether for how the whole species is doing.

Borrowed from the vet clinic

The idea didn't start with penguins. Copper- and zinc-infused microfiber vests have been used for years on injured dogs and cats, where veterinarians found the metals sped up healing of skin wounds. Researchers at Buin Zoo wondered whether the same fabric could work on a very different kind of patient.

"For years, vests with microfibers containing elements like copper and zinc have been tested on pets, particularly dogs and cats, and have greatly helped in the recovery of skin wounds," said Ignacio Idalsoaga, the zoo's director. "We began to wonder — why can't this be used on penguins?"

Staff took body measurements from penguins at the zoo to design the first bodysuits, snug enough to stay in place on a swimming, waddling bird without restricting its movement.

Why penguins need help now

The timing matters. Chilean and international researchers surveying the country's major Humboldt penguin breeding colonies in 2024 and 2025 recorded a 63% drop in active nests compared with the same sites three years earlier. The birds already face entanglement in fishing nets, plastic pollution, disease outbreaks, and competition with commercial fisheries for food.

El Niño is compounding the problem. The weather pattern pushes unusually warm water into the Pacific, driving away the cold-water fish Humboldt penguins depend on. Hungry parents are forced to travel farther for food, sometimes leaving nests and chicks behind for longer stretches — and the birds that do make it back often carry fresh injuries from the harder trips.

"Especially now, with all the problems caused by El Niño, we're likely to see many abandoned chicks in the coming weeks, with injuries they suffer in the environment," Idalsoaga said.

Estefanía Guidotti, marketing manager at Kimba, the pet-apparel company producing the vests, said copper and zinc help prevent bacteria, fungi, and mites from colonizing a wound during recovery, while zinc also encourages the formation of new blood vessels — speeding the healing of damaged tissue. For a species that spends most of its life in and out of saltwater, keeping a wound clean while it heals is unusually difficult, which is exactly the gap the vests are designed to close.

If the early trials hold up, Buin Zoo and partner rehabilitation centers plan to expand the vest program to other rescued seabirds along Chile's coast, giving rescuers one more low-tech tool against a very modern set of threats.

Read more from the Associated Press on the vest trials, or see the BirdLife DataZone species factsheet for more on Humboldt penguin conservation status.