Zoologist Li Dong prepares to release a bird back into the wild near Nanning's airport. [Photo provided to China Daily]

Li Dong grows plants to ensure the safety of aircraft.

The 33-year-old hopes that planting Wedelia trilobata, a low-growing species with yellow flowers and a special smell, will keep birds away from the Nanning Wuxu International Airport since there is no food or nesting space for them.

As there are more flights than before and China's ecology is improving, birds are a major problem in civil aviation. Collisions often occur during takeoffs, the initial climbs and landings, and pose a significant threat to aircraft safety.

"It's like tackling a problem at its source. If we can successfully change the habitats of birds, they won't frequent the airport and such collisions won't happen," says Li, who works at the airport in Nanning, capital of the Guangxi Zhuang autonomous region.

"It will greatly reduce our workloads and economic input, and it's environmentally friendly."

Originally from the Americas, the plant is often cultivated as an ornamental ground cover. It grows quickly and doesn't need much labor to maintain.

Li has spent several years on her ongoing experiment. It will produce results in the next year or so.

In the coming spring, she plans to grow the plant on a 6.67-hectare plot near the airport for her final research.

"As long as the land area is large enough, it will be easier to see its effects and I will get solid academic results via a larger sample," she says.

"I'm really looking forward to it. If it succeeds, it's possible to adopt the method to prevent bird hazards here and promote it to other airports as well."

The common methods of bird strike prevention all over the world are to scare birds away, using gas guns and ultrasonic devices. Some areas also spray pesticide to reduce insects, a food resource of birds.

Li did her postgraduate studies at Guangxi University, where she studied wildlife protection.

She began to work at the Nanning airport in 2011 and was responsible for bird-strike prevention.

This was the first time that airports under the management of Central and Southern Regional Administration of the Civil Aviation Administration of China recruited someone specialized in zoology.

Last year, she transferred to the engineering management department, but she still advises her colleagues about bird-strike prevention.

According to a report released by authorities in December 2016, 3,816 cases of bird hits were reported in China in 2015, 185 of which became flight incidents. And it is estimated that the economic losses they caused that year totaled about 120 million yuan ($17.4 million).

The report showed that bird strikes often happened in spring, summer and autumn. The peak months were September and October, which coincide with bird breeding and migrations in China.

"At first, it was really hard for me to adjust to the work environment. While I was supposed to protect wildlife with my knowledge, my duty at work was to keep birds away from the airport," Li says.

"I took the job by chance. But after struggling for a while, I decided that I'd use my expertise to prove my ability."

The turning point came when an idea suddenly struck her a year later. She found a vacant lot about half the size of a soccer field and started to sow seeds and irrigate the land.

She happened to choose the summer to grow the plant. So, she had to wear a straw hat and carry buckets of water under the hot sun. Luckily, her colleagues lent a hand.

"Many people have tried to grow plants to drive the birds away. But what matters most is whether the vegetation can survive in competition with weeds," she says.

It turns out that the plant is suited to the poor soil at the airport. So, she continued her experiment. It lasted for more than three years, with each stage taking about one year.

In the second stage, she started to figure out how to speed up its growth by using different cultivation methods. In the third stage, her focus was to research the effects of large-scale growth.

Her efforts received attention in 2016. A professor from the China Academy of Civil Aviation Science and Technology showed interest in the program and offered her research funding after visiting the site.

In 2017, she won the National May 1 Labor Medal in the civil aviation industry. The honor was awarded by the All-China Federation of Trade Unions.

"Many people don't take bird-strike prevention seriously and think we set off firecrackers to scare birds away," she says.

"It's supposed to be a 9-to-5 job. But I follow the birds' daily schedule. So, I wake up at dawn, take a nap at noon and continue to observe birds until dusk."

At first, she often patrolled the area to become familiar with the environment.

She then observed the birds flying into the area and figured out their numbers, the heights at which they flew, their behaviors and whether there were nocturnal species.

She later started to visit the surrounding areas to find out why birds were attracted to the airport.

"Data counts in research. So I recorded my observations in a notebook－a habit formed in my postgraduate studies," she says.

"Many people may think it's tiring to observe birds all day long. But I like to be in nature. I also enjoy doing data analyses－it allows me to be by myself and get to the crux of the problem."

She's now able to estimate when a specific species will appear, so her colleagues can prepare to scare the birds away.