We have lift off.

The endangered piping plover chicks — whose presence helped torpedo a major music festival at Montrose Beach that was scheduled to take place later this month — have begun to fly.

The two chicks were observed over the weekend flapping into the air — allowing them to evade threats and significantly increasing their chances of survival.

“Their job now will be to eat as much as they can to get strong so they can begin their southward migration, which will probably begin in a couple weeks,” according to Louise Clemency, field supervisor for the Chicago office of the U.S. Fish and Wildlife Service.

Their nesting area at the south end of the beach — which remains a refuge for the birds during busy beach hours — will remain roped off as long as the birds seek safety there, Clemency said.

The birds’ presence on the beach — they apparently arrived in May — drew gushing bird-lovers and set off a battle with organizers of the Mamby on the Beach music festival that was scheduled to be held on the beach later this summer.

Eventually, on July 19, two days after the chicks began to hatch, came the announcement that the festival — set for Aug. 23 and 24 — would be canceled.

A Herculean effort has gone into saving the birds.

An online petition collected nearly 7,000 signatures urging the concert’s cancellation.

Volunteers from the birding community stood guard by their nest during daytime hours. The Chicago Park District removed several volleyball courts that abutted their sandy nesting ground.

And just days before the birds took flight, Brad Semel, a biologist with the Illinois Department of Natural Resources, ran to their aid as two peregrine falcons — possibly looking to make a meal of the plovers — soared overhead.

“It was one of the more alarming moments with the plovers,” Clemency said.

“The chicks’ dad was giving just a continuous and urgent alarm call. It was a piping sound, almost like a flute noise, indicating to the chicks there’s danger up above and to flatten themselves down in the sand and become practically invisible.”

The father is still with the chicks. Their mother flew south recently.

One of the chicks’ siblings died late last month, despite an effort to hurry the lethargic bird to the Lincoln Park Zoo for care. Another never hatched.

A fifty percent survival rate is about average among piping plover chicks.

A previous batch of four eggs from the same plover parents at Montrose Beach were transported in June to a hatching facility in Northern Michigan because rising lake waters threatened their nest. None of the eggs hatched.

Birding enthusiasts were elated the plovers chose to stick around, move to higher ground and give it another go. Some were moved to tears when the birds took flight.

“I’m choking up right now,” Tamima Itani, treasurer of the Illinois Ornithological Society, said. “So many people said it was just too difficult on Montrose Beach for them to survive.”

The hope among bird lovers is that piping plovers will continue to mate and raise chicks on Chicago beaches.

“There are more and more busy beaches and fewer and fewer remote beaches,” Clemency said. “Perhaps they’ll be comfortable on our beaches and help turn around the population.”