Two national second-class protected animals, a red-footed booby (Sula sula) and a Malayan night heron (Gorsachius melanolophus), were released back to nature at Xichong beach and Shatoujiao, respectively, Tuesday with the help from professional workers, according to Shenzhen Evening News.

A research team from Shenzhen University (SZU) equipped them with a GPS tracking device that meets international standards to facilitate collection of research data.

The two precious birds had “sought help” from citizens, according to the News.

A worker releases a red-footed booby to the wild on the shores of Xichong beach in Dapeng New District on Tuesday. Li Jingchuan

Shenzhen nature reserve management center received a report Aug. 20 that an unknown bird flew to a home at a residential compound in Nanwan Subdistrict in Longgang District. The bird could not fly due to some physical problems.

Xu Jianyong, a staff member of the center, rushed to the property management center after receiving the report and found that the bird is a rare juvenile Malayan night heron. Before this, Shenzhen had no successful cases rescuing Malayan night herons.

A Malayan night heron being released to the wild at Wutong Mountain on Tuesday.

Veterinarian Xiao Lichun carefully checked the bird, finding it only weighed 407 grams. The nature reserve management center then worked out a plan to increase its nutrition, and SZU’s College of Life Sciences and Oceanography and its ecology research team also sent a research team to participate in the rescue work.

With joint efforts, the bird’s weight reached 512 grams, meeting an appropriate physical condition to survive in the wild.

On Aug. 22, the center got another call from citizens who spotted a red-footed booby on a fishing boat. Citizens later sent the bird to the center.

The red-footed booby was found very weak, with obvious keel protrusions and severe atrophy of both its pectoral muscles. Moreover, it weighed only 462 grams and was diagnosed with excessive hunger and malnutrition.

The bird’s situation improved after being fed a nutrient solution for four days and it gained its ability to fly.

Two bird-watching enthusiasts went to the scene to observe the release activity Tuesday. Zhang Jie, one of the enthusiasts, called for more news reports on animal rescue cases to inform citizens about wildlife rescue and suggested that citizens be invited to join rescue work.