A pair of Chinese mergansers return to a river in Zunyi, Guizhou province, in February. [Photo/China Daily]

Chinese merganser released into wild after being first in nation to be artificially incubated

After living at the wildlife rescue station of the Changbai Mountain Nature Conservation Management Center for nearly three months, a Chinese merganser and a mallard were released into the Toudao River in Jilin province on Aug 13.

Wading into the river, they embarked on a journey to find a new home in nature.

The Chinese merganser was the first in China to be successfully artificially incubated and raised in the Changbai Mountain region, according to an expert.

Both male and female mergansers have gray, scaly patterns on their bodies with long, reddish-brown crown feathers. The main difference between the two is that the male's neck is dark green, while the female's is brown.

The rare, beautiful waterfowl species has existed for over 10 million years, which is why the birds are often referred to as "living fossils with wings".

It is estimated that 2,400 to 4,500 wild Chinese mergansers are left in the world, according to the center. The species has been on the Red List of Threatened Species of the International Union for Conservation of Nature, and it's also under first-grade State protection in China.

A juvenile Chinese merganser is seen at the wildlife rescue station of the Changbai Mountain Nature Conservation Management Center in Jilin. [Photo/China Daily]

Its presence in a wetland is indicative of the area's ecological health, as the birds require a clean aquatic environment and generally choose to live near unpolluted bodies of water and in nature reserves.

"During the daily observation of the Chinese mergansers along the Toudao River on May 17, our staff members saw a mother leading her newborn chicks to jump from the nest on the tree to the ground," said Cui Xiucheng, a veterinarian of the station. "Seven baby birds and another three unhatched duck eggs were found — two in the nest and one on the ground."

The workers took the three eggs back to the rescue station for artificial incubation. On the way, they kept the eggs warm by placing them inside their clothing. "The temperature needs for the incubation of the Chinese merganser are quite high," Cui said. "We made several incubation attempts in past years, but were unsuccessful."

Cui put the three eggs in an incubator consisting of a styrofoam box, an electric hot plate and an instrument used to control the temperature. "I developed the incubator about a year ago and tried to incubate at different temperatures," he said. "This time, I set the temperature at 38.2 C."

He also put a hot water bottle in the box to help maintain the ideal temperature.

"Every four hours, we would turn the eggs to ensure that the heat could penetrate evenly," he said. "We also sprayed warm water twice every 24 hours on the eggshells to keep them moist."

Ten days later, a Chinese merganser and a mallard finally hatched on the early morning of May 27, the latter of which hatched from the egg found on the ground.

A juvenile Chinese merganser is banded before being released into the wild. [Photo/China Daily]

The birds were put under observation for 24 hours, and then Cui began to feed them egg yolks and glucose powder using a small syringe.

"Four days later, the birds could be fed small live fish and shrimp," he said. "We also had to pay a lot of attention to their health by monitoring their weight."

The weight of the Chinese merganser had climbed from about 75 grams when it was born to more than 800 grams when it was released at the river, Cui said.

"As far as I know, there had been no successful artificial incubation of the Chinese merganser in the Changbai Mountain region or even across the country," he said. "Now we have gained more experience with artificial incubation and are fully prepared for such situations in the future, which also provides hope for the survival of these abandoned duck eggs."

Located in the Changbai Mountain Nature Reserve, the Toudao River is one of the most important habitats for the mergansers.

"Every year around March 10, a group of Chinese mergansers migrate from the southern regions to the river to reproduce," said Luan Jian, a staff member at the management center. "We have placed great emphasis on employing a series of methods to provide the birds with a more comfortable habitat, including building artificial bird nests, adding new fish fry and increasing daily monitoring.

"Data shows that this year, 16 pairs of Chinese mergansers have built their nests in the Toudao River area, and 140 eggs have been incubated," he added.