OIA, Spain — Since medieval times, the people of Galicia have ritually rounded up the horses that roam wild in the green forests and hills of northwestern Spain.
At least once a year, during the Rapa das Bestas, or Capture of the Beasts, the short and sturdy Galician mountain horses are corralled.
Ranchers, who let their horses roam free for most of the year, track them down to cut their manes and tails, which were once sold to stuff mattresses and shoulder pads. Nowadays, the ranchers disinfect the horses, and sometimes vaccinate them. New foals are branded before being returned to the wild.
Some ranchers also earn a small income by selling their animals for meat, even though few Spaniards eat horses.
The roundup “is a way of continuing what our fathers and grandfathers always did,” said Gerra González Alonso, 54, who tracked down four of his horses. “Some people love to hunt animals, but I prefer to search for my horses.”
But like many traditions, the roundup is colliding with modern rules and sensibilities that challenge its practices and threaten its longevity. Animal rights activists condemn the ritual as mistreatment of horses.
Galicia’s roundups differ in their timing, their scale and the methods that ranchers use to capture and handle their horses.
The roundup in Oia takes place in the hills above a monastery. The practice of keeping Galicia’s horses in the wild has a historical link with the Catholic Church, which allowed the clergy to own horses but not look after them.
According to legend, Galicia’s main roundup — 70 miles away in Sabucedo — started after horses were donated to the parish to thank the patron saint for sparing residents from the plague.
The ranchers consider putting their horses to pasture in the woods the most efficient way to manage the undergrowth in a region that is otherwise prone to wildfires.
“Horses are the best forest cleaners,” Mr. González Alonso said. “A cow will only eat grass, but a horse will go for anything around the trees.”
But tougher and more expensive insurance and identification rules have forced many ranchers to abandon keeping horses in the wild.
Over all, the number of horses kept in the wild has fallen to about 11,000 from 20,000 over the last 15 years, according to Xosé Henrique Bazal, the president of the roundup association in Sabucedo.
Over four days each July, Sabucedo’s ranchers round up horses and then overpower them by hand. It is a sellout spectacle that is officially recognized as a tourism fiesta and draws about 4,500 spectators.
Unlike Sabucedo’s paying event, Oia’s roundup is a low-key affair, attended only by ranchers and local spectators. Some arrive early to admire the horses, as they gradually emerge from the woods and are then corralled by ranchers on horseback.
“Everything they do is pure artistry,” said José Manuel Costas, a retired shipbuilder who has watched roundups for 70 years, since he was a small boy.
Rather than finding any evidence of animal mistreatment, he said, “I see here people who love animals and nature.”
Still, Oia’s event circumvents Spanish legislation that forbids the transport and slaughter of animals without full certification.
“Everything here has been going on in the same way for so long that the authorities turn a blind eye,” said Manuel Fernández González, a retired butcher.
Horse meat aficionados swear by the quality of the product. “It’s probably the healthiest meat you could eat, coming from a horse that’s really part of a natural forest ecosystem,” said Xabier Fernández, who buys a foal every year.
The ranchers, too, deny any mistreatment. Instead, they say activists unfairly lump their roundups in with their broader campaign to ban animal fiestas in Spain, particularly traditional bullfights.
The activism and tougher government regulations do little to protect horses and much to destroy an ancient way of life, they say.
The ranchers have held protests against Spanish legislation forcing horses to have identity chips, saying they are unnecessary.
“I can identify a horse by looking at it, without needing a chip that also requires investing in an electronic reader,” said Ignacio Español, a rancher. “We’re being pushed to abandon our horses because of all the regulations.”
The ranchers sued to be exempted from the regulation, but the Supreme Court ruled against them in July.
Mr. Español said he planned to insert the compulsory chip, but also continue using the traditional hot iron method to brand his foals.
Government officials say a chip and an insurance policy are essential to establish accident liability, in particular when horses leave the woods and run onto a road.
Three years ago, one of Mr. Español’s horses died after being hit by a car while crossing the coastal road that links Galicia to Portugal.
But the ranchers believe that the problem is mostly irresponsible drivers, who speed along country roads and “just don’t respect the horses,” said José Fernández Martínez, the president of an association of ranchers.
“Modern society is losing a way of life that has kept us and animals in harmony,” he said.
Laura Duarte, an official from Pacma, a political party promoting animal rights, said that checking on the health of horses was laudable, but that other aspects of the roundup were unjustifiable.
“We don’t criticize what’s being done, but how it’s been done,” she said, “because it causes terrible stress to animals that live in the wild and aren’t used to human contact.”
“To brand a horse with hot iron can only cause huge suffering,” she said.
Even if a roundup cannot be compared to bullfighting in terms of cruelty, Ms. Duarte added, “the argument in its defense is the same, which is to evoke tradition.”
“Any tradition that harms animals must be reviewed,” she said, “and doing something for a very long time doesn’t mean it shouldn’t now be adapted to our times.”