Cautiously, Dimitri, a nearly two-year-old Amur tiger, placed a paw into an elevated tunnel and was greeted by a roar of applause from humans below.
Soon, Dimitri's twin brother Wiz joined him in romping through their new open-air pathway, which both tigers clearly enjoyed. The two brothers nuzzled and pawed each other as onlookers cheered and snapped cell phone photographs.
This was the scene after the Philadelphia Zoo's Big Cat Crossing was officially opened by Gov. Tom Corbett's young grandson Liam on Wednesday morning.
"You are leading not the nation but the world in how we treat animals in our zoos," Corbett declared at the opening, noting the Philadelphia Zoo's commitment to treating animals humanely and respectfully goes back to its founding in 1874.
Corbett said that while most adults take in zoos calmly, he wonders if it is because they have lost their "sense of wonder."
But the faces of children seeing the zoo for the first time are always "bright with wonder ... with eyes wide open and smiles across their faces," Corbett said, thanks to attractions like Big Cat Crossing.
Big Cat Crossing is the third tunnel in the zoo to allow animals to "run, swing and roam from their usual homes to distant places across the zoo," said the zoo's board chairman Jay Calvert, as part of the zoo's signature "Zoo360" system.
The Big Cat Crossing is designed to integrate into the pre-existing Big Cat Canyon zoo area, with the new pathways leading directly out of the big cats' areas.
It will open to public visitors to the zoo on Saturday, May 10.
Dangerous but endangered
Dimitri, born June 28, 2012, (just before midnight) and Whiz, born June 29, just after midnight, both hail from Columbus, Ohio.
Zoo president Vikram Dewan said the Philadelphia Zoo is dedicated to protecting rare species from extinction due to deforestation by palm oil manufacturers in places like Sumatra.
Dewan urged visitors to only buy deforestation-free palm oil.