Desert oasis a lifeline for migratory birds

Satellite tracking

Restoration, however, is only part of the effort. Conservation workers also need to know how birds are using the wetlands and where they go after leaving.

The reserve has monitored birds since 2014, Shan said.

Since 2022, conservation workers have used breeding observations, behavioral studies and satellite tracking to monitor black storks and other rare birds.

So far, 39 black storks have been fitted with satellite trackers, mainly to study the migratory routes of birds that breed in Zhangye, when they leave, where they stop and where they spend the winter.

The tracking revealed a regular migratory route for the Zhangye population.

The birds generally leave in mid-to-late October, cross the Qilian Mountains and stop at wetlands in places including Qinghai province and Zoige Grassland before continuing through Yunnan province to Myanmar, where they spend the winter.

They return along roughly the same route the following year, Shan said.

The value of the monitoring was demonstrated in March 2026, when tracking data showed that a black stork fitted with a satellite device in September 2025 had returned to Zhengyi Gorge. Field checks later confirmed that it had successfully bred there.

"It was a significant finding for our research into the breeding habits and migration patterns of black storks," Shan said, adding that such findings help researchers develop more targeted protection measures.

During the 2026 breeding season, workers conducted three rounds of full-coverage surveys. They recorded 23 black stork chicks hatching, with 19 becoming fledglings.

The longer-term monitoring also offers a more cautious way of reading changes in bird numbers.

A synchronized survey in 2024 recorded 675 black storks in the reserve, while a subsequent survey in 2025 recorded 455. Shan said year-to-year differences do not necessarily indicate a change in the quality of the wetland environment.

Bird monitoring is a long-term process and comparisons are generally more meaningful over periods of about five years, he said. Annual numbers can be affected by random or temporary factors, so a decline in one year does not necessarily mean that the wetland has deteriorated.

"Over a longer period, such as 10 years, bird numbers have shown an overall upward trend," Shan said. "That suggests the environment is gradually improving."