A black-and-white ruffed lemur enjoys a watermelon treat at the San Francisco Zoo on Independence Day. (Photo courtesy of Zan Francisco Zoo)

Human beings weren’t the only creatures celebrating July 4 this week. The lemurs of the San Francisco Zoo got a heaping helping of watermelon in celebration of Independence Day.

As part of a four-day Fourth of July event at the San Francisco Zoo & Gardens in the city’s outer Sunset District, watermelon slices were presented to the ring-tailed lemurs at 11 a.m. as zoo patrons watched in delight.

“Watermelon is considered a special treat offered one day a year and it happened to be today,” zoo spokeswoman Nancy Chan said. “Actually, their favorite food item is figs, but watermelon comes in a close second.”

The zoo has 19 lemurs but only 17, which are in the Lipman Family Lemur Forest, received watermelon.

Chan said lemurs are the most endangered mammals in the world. They are only found on the island of Madagascar, off the coast of Africa.

There, 113 known species of lemurs exist and the San Francisco Zoo has the largest mixed group of them outside of Madagascar.