However, in recent years, science has come to the rescue of exhausted researchers by way of the aforementioned reproductive hormone testing.

They no longer have to rely on their instincts and experience alone to determine the brief window of time for mating.

Once the hormones of the pandas are set to change, the center will collect urine samples and gradually increase the sampling frequency, says Zhao Pengpeng, a senior veterinarian.

"It is like a race against time when multiple pandas enter their rutting periods during the peak season. It is often the case that their previous urine samples are still being tested when the latest urine samples are collected and sent to us," says Shen Jiena, an assistant engineer there.

"Every single minute or second matters, since the best mating period may only last several hours. Once you miss the window, you have to wait for the following year," she adds.

After identifying the best mating time, the center will then help giant pandas conduct breeding activities through natural mating or assisted reproduction.

In 2020, four giant pandas were born at the center, the world's third-largest breeding base for the animal.

"We spare no effort to help every female panda that is suitable for breeding to have cubs. When they give birth to new cubs, it is a happy moment for us as well," Zhang says.