(CNN) -- So how did he get out?
Rusty the red panda caused a stir in Washington and on social media when he was reported missing from his enclosure at the National Zoo on Monday. His absence was noted just before 8 a.m., and he remained on the lam for hours until a Washingtonian tweeted a photo of him hiding out in the Adams Morgan neighborhood, nearly a mile from home.
Rusty was recovered by zoo officials about 2:30 p.m., no worse for the wear.
His intrepid escape initially baffled zoo officials, who said Rusty's enclosure previously had a strong track record. The exhibit has housed red pandas for several years without issue. And Rusty's companion, 5-year-old Shama, remained in the zoo habitat even as Rusty made his escape.
In the days since the escape, the zoo convened a "multidisciplinary team of zoo experts" to investigate the enclosure, recent photos and security footage in order to come to a tentative verdict:
According to zoo officials, "It is highly likely that Rusty left his enclosure ... through the tree canopy in his exhibit."
The canopy was made all the more accessible due to rain, the zoo officials conclude, lowering tree limbs to within reach of the edge of Rusty's enclosure. Additionally, perimeter bamboo may have sagged, creating a bridge. It appears that Rusty, who the zoo says possesses "climbing ability and agility," slipped out and didn't look back.
The zoo says no panda tracks were found, so his exact route will remain a mystery. But in the wake of Rusty's cell break, zoo officials say they plan to trim plants and create additional barriers to ensure another 30 inches of bamboo- and tree-free space.
As of Friday, Rusty, who is just shy of 1 year old, continues to do well. Zoo veterinarians have administered a rabies booster vaccination. And, while he remains at the hospital, zoo officials expect him to return to exhibit by July Fourth.
And so, the only remaining mystery is why.
CNN's Margaret Perry contributed to this report.