An investigation determined Rusty the red panda likely climbed out through the trees in his exhibit. Now the limbs have been cut back, and the zoo has two cameras aimed at the red panda yard around the clock.
According to a zoo report on the escape obtained by The Associated Press following a public records request, the zoo has been investigating and observing Rusty ever since he was found in a nearby Washington neighborhood June 24. The report was filed with the Association of Zoos and Aquariums, an accrediting body.
The zoo's investigation found Rusty likely escaped late June 23 or early June 24 through tree limbs hanging low in his exhibit after a rain. No red panda tracks were found outside the exhibit, the report noted, so the exact route of his escape couldn't be determined.
Animal keepers have kept watch on Rusty's activity by day and night as an extra precaution. He returned to his public exhibit July 9 and spent the night outside for the first time Monday night with two keepers on duty to observe his behavior. Nothing seemed out of the ordinary, a spokeswoman said.
"We identified and solved the problem that allowed Rusty to get out," the report noted. As of July 1, "we are confident that the exhibit can contain him."
The incident prompted the zoo to begin regular checks of all vegetation around enclosures to ensure animal containment is secure. There has been increased trimming throughout the zoo, said spokeswoman Pamela Baker-Masson.
The U.S. Department of Agriculture sent an inspector to the zoo following the escape, and a copy of the brief inspection report was provided to the AP. On June 27, veterinarian Gloria McFadden found "an appropriate corrective action plan" had been developed following the escape.
Rusty was born in July 2012 at the Lincoln Children's Zoo in Lincoln, Neb. He was transferred to the National Zoo in April under breeding recommendations from the zoos association. He was moved into his exhibit in June after time in quarantine.
Less than a month later, the young, curious male was found exploring his new city in the Adams Morgan neighborhood. Residents snapped pictures of him along sidewalks and homes before zoo keepers cornered him in a tree and snagged him a net nearly ¾ of a mile from the zoo.
Following the escape, the zoo has removed bamboo — a favorite food for red pandas — around the red panda exhibit. The plants had grown high and likely helped create a "vegetative bridge" out of the enclosure. The idea of a snack may have drawn Rusty out for a treat, the report noted.
"Horticulture staff regularly trim vegetation in animal habitats to make sure containment is not compromised," said Baker-Masson, the zoo's spokeswoman. "In this case, zoo staff underestimated the growth brought about by perfect weather conditions (weeks of consistent rain)."
Hotwire lines that carry an electric current in the enclosure also were assessed and upgraded. A new visitor wall was added to create more tree-free space.
According to the Association of Zoos and Aquariums guidelines for red pandas, enclosures must be created with the species' mobility in mind.
"Red pandas are excellent climbers, but poor jumpers, so dry-moated enclosures contain them well," according to an excerpt from the association's manual in the zoo's report. "Do not let the branches of climbing trees overhang the boundary fence."
It hasn't been determined if hotwire is an effective barrier, but it is sometimes used to keep wildlife from entering the exhibit. Hotwire should be considered a secondary barrier, according to the zoo association.
The National Zoo uses hotwire throughout the zoo as a deterrent in conjunction with walls, fences or other barriers, Baker-Masson said.
Unlike giant pandas, red pandas are not members of the bear family. They are slightly larger than a domestic cat and look similar to a raccoon. Red pandas are vulnerable in the wild and are native to Asia. Scientists believe about 10,000 of them remain.
National Zoo: http://nationalzoo.si.edu/
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Copyright 2013 The Associated Press.