A beloved Jacksonville Zoo and Gardens resident — a capybara named Theo — has died at age 13.

The life expectancy of a capybara in human care is typically 10 to 12 years. The zoo celebrated Theo’s latest milestone birthday on St. Patrick’s Day, but her health was declining, according to the zoo.

“Our dedicated team of veterinarians and animal care staff had been monitoring her for age-related health issues that could no longer be managed without significantly impacting her quality of life,” the zoo said in a Facebook post. “The difficult decision was made to humanely euthanize her. We are heartbroken.”

Jacksonville Zoo euthanizes Theo the capybara after health decline

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Theo the capybara eats a snack at the Jacksonville Zoo and Gardens. She died recently at age 13.

Theo was not born in Jacksonville, but lived at the local zoo “most of her life,” spokeswoman Emuily Long said. She had no offspring and, with her death, there are none of her species at the zoo.

Theo was not just popular with zoo staff, as dozens of people commented on the loss, many of them saying they sought her out on visits there. She was sweet and made them smile, they said.

“I’m am so sad … and I’m just a zoo regular. I can’t imagine how the staff is feeling,” commented Jill Matejcek. “They must be heartbroken.”

On zoo visits, Matejcek said she always stopped to see Theo and “sang the capybara song to her.” The viral TikTok song was created by a 22-year-old Russian blogger, according to news reports.

Theo, a 13-year-old capybara, was humanely euthanized at the Jacksonville Zoo and Gardens due age-related health issues.

Theo, a 13-year-old capybara, was humanely euthanized at the Jacksonville Zoo and Gardens due age-related health issues.

“Cheesy I know,” Matejcek said. “But I loved seeing her and am actually crying tears at my office right now.”

Zoo staff said Theo was known for her love of snacks, scratches and taking afternoon dips in the pool on warm days.

“With her sweet, easygoing personality, Theo brought joy to all who had the privilege of caring for her and visiting her,” the zoo said. “We are grateful for the many happy memories she created throughout her long life.”

What are capybaras?

Capybaras are semi-aquatic mammals and the biggest rodents on Earth, according to National Geographic. They are about 4.6 feet long, up to 2 feet high at shoulders and weigh from 77 to 143 pounds, according to the magazine.

The zoo’s description: “Brown-gray fur, with a hint of reddish coloring. The back legs are longer, and feet have four webbed-like toes. The front legs are shorter, with feet having only three toes. On the top of the cylinder-shaped head are the eyes, ears and nostrils.”

Capybara’s are native to Central and South America from Panama south to northern Argentina and Uruguay in tropical rain forests, grasslands, rivers and lakes. In Jacksonville, Theo lived in the zoo’s Range of the Jaguar exhibit.

Theo the capybara snacks at the Jacksonville Zoo and Gardens.

Theo the capybara snacks at the Jacksonville Zoo and Gardens.

In the wild, their life expectancy is about seven years.

10 Best Zoos

The zoo recently finished fourth in the 10 Best Zoos in the US poll, behind the Henry Doorly Zoo and Aquarium in Nebraska, the Cheyenne Mountain Zoo in Colorado and the Cincinnati Zoo & Botanical Garden in Ohio. The zoo finished in the same position in last year’s poll.

The Brevard Zoo in Melbourne is the only other Florida facility to make the list, finishing fifth.

bcravey@jacksonville.com, (904) 359-4109

This article originally appeared on Florida Times-Union: ‘Sweet, easygoing’ Jacksonville Zoo capybara Theo dies at 13