Crested ibises fly in the sky in Zhaigou Village, Ningshan County of northwest China's Shaanxi Province, Oct. 10, 2022. In recent years, Ningshan County has made great efforts in ecological protection and green development, with the local forest coverage rate reaching 96.24 percent and the population of crested ibises, giant pandas, and golden snub-nosed monkeys growing. (Photo/Xinhua)
Sampling air to detect the presence of crested ibises represents a groundbreaking application of environmental DNA (eDNA) technology in monitoring this species in China. This innovation opens an unprecedented new perspective for studying their distribution and ecological status, China Central Television (CCTV) News reported on Sunday.
At the Weihe River estuary wetland in Xianyang, Northwest China's Shaanxi Province, monitoring personnel used an environmental air DNA sampler to collect air samples in search of crested ibis traces.
The device traps DNA from crested ibises present in the ambient air onto a membrane. This membrane is then taken back to the laboratory for extraction and analysis to confirm the bird's presence, according to the CCTV report.
To detect crested ibis DNA amid samples contaminated by human and other bird DNA, a local research team developed a targeted monitoring technology specifically for the species, according to CCTV News.
Using a real-time quantitative polymerase chain reaction (qPCR) monitoring method, the device can detect even a single DNA molecule in the environment, said Luo Yining, deputy director of the ecological quality monitoring office at the Shaanxi Provincial Environmental Monitoring Center, CCTV News reported.
This technology enables monitoring animal presence without the need for capture, said Zhang Cuirong, deputy director of the analysis and testing center at Xianyang Environmental Monitoring Station.
As the technology is refined, it will support monitoring of crested ibis population and distribution, she said, adding that in the future, this technology can also be applied to monitor other rare species.
Since detection of crested ibis traces in air requires comparison against a database, establishing a genetic database for this species is critical, the report stated.
The research team has also compiled genomic data for crested ibises from more than three cities, covering birds of different ages, sexes, and geographical populations. This provides a precise standard for the comparison of environmental DNA in future studies.
Shaanxi Province is home to more than 7,700 crested ibises, accounting for 80 percent of China's total and over 71 percent of the global population, Science and Technology Daily reported.
