12/06/2012 03:21 EST | Updated 02/05/2013 05:12 EST

Testing reveals Canada-bound pandas were both female

After discovering that both pandas slated to visit Canada next year were female, China is replacing one of them with a male.

The Toronto Zoo was set to receive two giant pandas, known as Er Shun and Ji Li, in the spring of next year.

But the zoo’s colleagues in China have advised that both Er Shun and Ji Li are female.

The Toronto Zoo issued a news release Thursday explaining the situation and advising the public that a male panda named Da Mao will be coming in place of Ji Li.

"With younger giant pandas it is more difficult to determine the sex and this is confirmed through genetic testing techniques," said Dr. William Rapley, the Toronto Zoo’s executive director of conservation, education and wildlife.

"We are appreciative of the fact that the Chinese Association of Zoological Gardens conducted the studies so that the situation can be rectified and we can continue to move forward in smoothly handling this important conservation breeding loan."

Da Mao was born at the Chengdu Research Base of Giant Panda Breeding on Sept. 1, 2008.

The plan to bring the pandas to Canada was announced earlier this year by Prime Minister Stephen Harper at the close of an official visit to China.

"It is a tremendous honour for Canada to be entrusted with two of China’s national treasures," Harper said at the time.

The pandas will spend five years at the Toronto Zoo, before moving to the Calgary Zoo for another five years.