For the past decade, China has been reintroducing captive-bred crested ibises into the wild as part of its efforts to save the once-threatened species.
In 2013, following the release of a group of 32 crested ibises near the Ju River in Tongchuan City, Shaanxi Province, northwest China, 16 locals offered to work as part-time observers to help record the birds' daily activities.
"We record how long they stay in their nests and how many times they catch food. The most important thing is to monitor their living habits. We record any place crested ibises appear, including where they live at night and where they look for food," said Yang Gangqi, one of the part-time crested Ibis observers.
Over the past 10 years, crested ibises released into the wild in Tongchuan have flown to other cities across Shaanxi Province, which has established at least five groups of such ibises.
"Throughout history, the crested ibis was a migratory bird species. After its habitat was narrowed to Yangxian County, it became a resident bird. By releasing the crested ibis in Tongchuan, Baoji and other locations across China, we are trying to help restore their seasonal migrations," said Chang Xiuyun, a senior engineer at Shaanxi Forestry Bureau.
The crested ibis used to be designated as "critically endangered" on the International Union for Conservation of Nature's red list due to its extremely low population in the 1980s.
The population of crested ibis has expanded greatly since then. As a result, restoring its historical distribution became a critical conservation strategy at the time.
Apart from strengthening protection methods, Shaanxi has also attempted artificial breeding since the 1990s. According to data from the National Forestry and Grassland Administration, a total of 202 crested ibises have been released into the wild in Tongchuan in the past decade.