Da Mao, a 4-year-old male panda from the Chengdu research base, is ready for express delivery to Canada on Monday at Shuangliu airport in Chengdu. [Cui Kai / For China Daily]

Two giant pandas left Chengdu, capital of Sichuan province, for Canada on Monday.

Da Mao, a 4-year-old male from the Chengdu Research Base of Giant PandaBreeding in Sichuan, and Er Shun, a 5-year-old female from Chongqing Zoo, will stayin Canada for 10 years under a conservation agreement between the two countries.

"The duo will spend five years at Toronto Zoo followed immediately by another fiveyears at Calgary Zoo," said Zhang Zhihe, chief of the Chengdu panda base.

Zhang said visitors to Toronto Zoo will be able to see the two pandas after amonthlong quarantine.

"The program will allow the Toronto and Calgary zoos to contribute to ongoinginternational efforts to increase the population of endangered giant pandas. Currently,fewer than 2,000 pandas remain in the wild," he said.

Toronto and Calgary have waited for about 20 years to see pandas at their zoosagain.

The Chinese tradition of sending the animals overseas dates to when the EmpressWu Zetian gave pandas to the Japanese emperor in 658.

On three occasions in the 1980s, Toronto, Calgary and Winnipeg zoos hostedChinese pandas for short-term visits.

"Qing Qing and Quan Quan's 100-day stay in Toronto in 1985 drew hundreds ofthousands of visitors. On the first two days, there were 35,000," Zhang said.

Oliver Claffey was one of the keepers who looked after the pandas in Toronto in 1985.He thinks this visit will be even more successful than the first one because the pandaswill be in the zoo for five years.

"This time, it's a long-term loan and I suspect that with the knowledge and staff wehave at Toronto Zoo, the pandas will breed and that's the idea," he told the CanadianBroadcasting Corporation.

FedEx, which has handled transportation for Da Mao and Er Shun to Canada, packedplenty of bamboo, bamboo shoots and apples for their more than 15 hour, 12,875 kmjourney.

Veterinarians from the Chengdu panda base and the Chongqing and Toronto zoostraveled with them.

Li Mingxi, a panda expert from the Chengdu base, said he will stay in Canada for sixmonths to help Da Mao adapt to the new environment.

"Initially, we had arranged for Ji Li, a female panda, to head for Canada because theChengdu panda base had been asked to supply a female, and Chongqing Zoo toprovide a male. But because Chongqing Zoo had mistaken Er Shun for a male anddiscovered her gender very late, we had to let Da Mao take the place of Ji Li," Zhangsaid.

With younger pandas it is more difficult to determine their sex and this is confirmedthrough genetic testing techniques, said William Rapley, Toronto Zoo's executivedirector of conservation, education and wildlife.

Tang Jiagui, a panda expert at Chongqing Zoo, said of Er Shun, "We did not find shewas a female until an all-round examination in late November."

News of the pandas' 10-year stay in Canada was announced by Canadian PrimeMinister Stephen Harper when he visited China last year.

"It is a tremendous honor for Canada to be entrusted with two of China's nationaltreasures," he said.