Nadya, a Siberian tiger at Six Flags Wild Safari in Jackson, New Jersey, gave birth last month to a rare litter of five cubs – equivalent to 1% of the Siberian tiger population.

One female cub was under the typical birth weight and received “around-the-clock bottle feedings until she began to thrive,” according to Six Flags.

“Without human intervention, she would not have survived,” said Six Flags Veterinarian Dr. Ken Keiffer, in prepared remarks. He says the birth survival rate of wild tigers is 50%.

The other cubs, three females and a male, each weighed a steady 6 lbs. at birth.

Visitors to the park will be able to see Nadya and her cubs in the coming weeks.