A 19-month-old red panda went missing from the Virginia Zoo this week — and officials say she may be roaming to find a mate.

Sunny the red panda was last seen in her enclosure in the “Asia — Trail of the Tiger” exhibit at the Norfolk zoo at 5 p.m. Monday. Zookeepers noticed she was missing during the first check of the animal habitats and launched a search of the grounds, where zoo staffers are hopeful she remains. But she also may have fallen victim to the stresses of mating season.

“It is red panda breeding season,” according to a post on the zoo’s website. “The animals become more agitated and could display a little abnormal and hyperactive behavior. Monday night it was rainy and windy. Sunny may have been on a slippery branch while Thomas, the male red panda, was pursuing her and caused her to slip and fall.”

Zoo officials and volunteers have searched nearby St. Mary’s Cemetery, Lafayette Park and neighborhoods of Lindenwood, Villa Heights and Riverview for the missing mammal — but as of early Thursday, she remains on the loose.

“We encourage the community to continue their search efforts by throughout looking in the trees in their backyards and neighborhoods located within a mile of the zoo,” the post continued, suggesting that people scan the tree canopy from a distance rather than looking at individual tree branches. “She will likely position herself to be able to people watch from a mid to high point in a tree or other climbable structure.”

While typically not aggressive, red pandas are wild animals and can be unpredictable, especially during mating season. Anyone who believes they’ve spotted the panda is asked to call the Virginia Zoo at (757) 777-7899 and not to touch, feed or try to capture Sunny.

The Norfolk Police Department on Tuesday used an infrared camera to search the zoo, but the reddish-brown panda — about the size of a raccoon — could not be found.

Red pandas, which are listed by the World Wildlife Federation as an endangered species, are native to China and the eastern Himalayas.

“Red pandas are very skillful and acrobatic animals that predominantly stay in trees,” according to a WWF website on the animals, which number fewer than 10,000 worldwide. “Almost 50 percent of the red panda’s habitat is in the Eastern Himalayas. They use their long, bushy tails for balance and to cover themselves in winter, presumably for warmth.”

Sunny came to the zoo in May from the Smithsonian’s Conservation Biology Institute, the Virginian-Pilot reports.

Red pandas apparently don’t like being caged, with several documented escapes, the newspaper reports. In 2007, a 1-year-old red panda named Yin slipped out of her enclosure at the Virginia Zoo twice in two months, but was found both times. The animals have also escaped from zoos in Washington, DC, the United Kingdom, the Netherlands and Germany.