On a cool summer night, Jiang Yao, a senior student at Nanjing Agricultural University in Jiangsu province, finished his day as an intern at Nanjing Hongshan Forest Zoo.

As he walked through the zoo alone, a group of fireflies flew around him. Standing amid their glow, Jiang knew immediately that this was where he belonged.

"As one particular firefly circled around me, everything seemed to be in perfect harmony. At that moment in 2019, I decided to work at the zoo," said Jiang, now 25.

After graduating from the university with a bachelor's degree in biotechnology in 2020, Jiang started work as a keeper at the forest zoo, which is home to more than 3,000 animals from 260 species.

Born and raised in a rural area of Jiangsu, he has loved animals and watched documentaries about them since childhood.

During his job interview at the zoo, when Jiang was asked if he had any experience in saving animals, he said the first one he helped rescue was a small turtle his father found in a river near his village.

"I was just a little boy when I saw my father take the turtle home, where he offered it to me as a pet. I immediately turned the offer down, telling him that a turtle is not a pet and I didn't want to treat it like a toy. My father was very supportive of me, and we returned to the river to release the creature. I was so happy for the turtle," Jiang said.

Jiang formed the idea of becoming a zoo keeper when he was a student. During his fieldwork on Huangshan Mountain, Anhui province, he once met a graduate student who researched short-tailed macaques. Jiang was highly impressed by the knowledge of these creatures that the student shared with him.

"The student named each macaque and could tell the differences between them, just like parents spotting differences between twins. His passion for animals touched me deeply, and I wanted to follow in his footsteps," Jiang said.

On his first day at Nanjing Hongshan Forest Zoo, Jiang cleaned the birdhouses — a task he tried to perform without disturbing the birds, which he also spent many hours observing. Next, he was assigned to the animal rescue center, and now he mainly works as an amphibian keeper at the zoo.

Some of the animals arrived at the zoo via the rescue center after being saved by local people, Jiang said. A small number of rescued animals are released back into the wild after receiving medical treatment, but 90 percent of them remain at the zoo.

Due to the illegal trade in animals, many of those that are rescued are alien species, meaning they have spread to areas outside their natural range and dispersal potential. Many of the animals that Jiang cares for are protected species confiscated from owners who bought them illegally.

The sulcata tortoise, also known as the African spurred tortoise, which is one of the largest tortoise species in the world, requires special care from Jiang. Housing these adult tortoises indoors can be difficult due to their size, but they need to be provided with a warm living area.

"The tortoises require hot temperatures to remain healthy and active. Nanjing usually starts to get cooler in September, so the tortoises need to be taken care of indoors, where they are placed in a heated shed equipped with purifiers to circulate the air," Jiang said.

"There are detailed duties and responsibilities for an animal keeper, and the job is far different from what I expected," Jiang said.

"I need to prioritize the health and welfare of the animals in my care, which means I must devote a significant amount of time to continuous learning."

Jiang said that as he is shy and not good at communicating with other people, his job as a keeper seems perfect for him. When the COVID-19 pandemic emerged, the zoo closed temporarily, and he stayed there for more than a week to take care of the animals.

"There were no visitors, so I did nothing but look after the animals. I never felt bored, and had a very happy time with them," he said.

Young visitors

Dating to the 1920s, Nanjing Hongshan Forest Zoo is one of the most popular in China, and due to its daily livestreaming programs, the number of its followers has risen significantly.

Shen Zhijun, head of the zoo, said it welcomed about 6.7 million visitors last year. Some 60 percent of them were in the 20-30 age group, and 60 percent came from outside Nanjing.

More young people such as Jiang are joining the zoo as keepers, Shen said. Of the 140 keepers at the zoo, 40 percent of them were born after 1995, and 20 of the keepers were born after 2000.

Jia Tianci, 28, takes care of some 20 wolves at the zoo, where he started work in 2020 after graduating from Nanjing Agricultural University with a bachelor's degree in veterinary medicine.

One of the animals in his care is Stanley, a gray wolf that arrived at the zoo in 2021.

"Stanley arrived in Nanjing from Beijing as part of our work with the reproductive management of the animals, so it was vital to find him a mate to conserve genetic diversity and ensure the long-term viability and sustainability of the breed. For me, it was just like being a father worried about his son's marriage," Jia said.

Stanley and his mate now have six cubs at the zoo, where Jia enjoys watching over them each day.

"Being a wolf keeper is a magical job. Wolves have a clear social structure. Each pack has dominant individuals as well as those who rank lower in the hierarchy, just like different positions in a business such as CEO, team leader and basic employees. I work for the animals, just like an employee," Jia said.

Born and raised in Nanjing, Jia dreamed of becoming a vet. His parents didn't understand his decision to become a keeper until they saw him take care of the wolves.

"I feel content when the wolves are mentally and physically healthy. Although they obviously cannot speak like humans, I can tell from changes in their excrement, such as its color, consistency and smell, whether they are healthy," Jia said.

In addition to acting as a keeper, Jia escorts and chats with visitors to the zoo.

"I remember my visit to a zoo during my childhood. I loved watching the monkeys and feeding them cookies. However, after becoming a keeper, I realized that this type of behavior was totally wrong," Jia said. "People love interacting with animals, but the first thing we tell visitors is not to disturb them. Behavior such as banging things, shouting at the animals and feeding them, are harmful."

The question of whether zoos are good or bad for animals is a delicate issue that has caused heated discussion. In modern society, zoos play a vital role in wildlife conservation, public education, and scientific research. However, some people insist that zoos do more harm than good.

Jia said: "At Nanjing Hongshan Forest Zoo, the old steel-bar enclosures and concrete cages have gone. We now use natural-looking barriers to separate the animals from the public, with habitats resembling the animals' living environment in the wild."

He added that a key task for the zoo's keepers is to implement enrichment programs to stimulate animals' natural instincts. Such programs include creating conditions for animals to hunt, forage and also stimulate them mentally and physically.

"We encourage visitors to respect the animals, which is also the first rule for staff members at the zoo," Jia said.

Shen, the zoo's head, said: "Traditionally, breeding programs at zoos have been regarded as relatively simple. However, this view fails to take into account the diverse environmental requirements of individual species."

Demanding work

In 2013, Nanjing Hongshan Forest Zoo started to recruit young keepers who have master's degrees. Shen said that certain people considered the recruitment of graduates with such degrees to be a total waste of talent.

"Taking care of wildlife, especially endangered and vulnerable species, is a highly demanding job that requires continuous study," Shen said. "Working at a zoo also calls for a broad knowledge of subjects such as biology, zoology and environmentalism."

Shen, who is in his 50s, said that during interviews at the zoo with job applicants, he notes the attitude they show toward animals.

"Many applicants tell me they have loved animals since childhood. They have cats or dogs at home, but we need more from them than that. We require people with qualities such as independence, stability, persistence and practicality," Shen said.

Dubbed "King of the Animals" on social media, Shen is one of the best-known zoo heads in China.

As a child, he dreamed of being a physician. He studied landscape architecture at university, and in 2008, started work at Nanjing Hongshan Forest Zoo, becoming the nation's youngest zoo director at that time. Since then, Shen has observed the animals at the zoo every day.

In 2021, when the zoo faced difficulties due to the pandemic, Shen took to the internet to introduce a 65-hectare wildlife park located in hillside forests north of Nanjing, with the idea of transforming the zoo from a traditional venue to one that values wildlife conservation.

Supporters were impressed by the efforts made by Shen and his team over the course of a decade, which changed the zoo's landscape and put an end to its animal shows — the financial lifeblood for many zoos.

Shen said: "People love coming to our zoo because they experience positive emotional connections with the animals. For example, when parents bring their children to see koalas, they love to see the koalas holding their joeys (babies).

"Visitors also remain very quiet and spend a long time watching the koalas sleeping. We try our best to enrich the animals' living environment so that they behave naturally. As a result, they are happy and confident, and our visitors can sense this."

Shen said he was inspired by his son to make changes to Nanjing Hongshan Forest Zoo. Around 2008, Shen offered to take his son, who was 10 at the time, to the zoo, but the boy said he did not want to go.

"He told me zoos were for smaller kids and he didn't think they provided enough fun for him," Shen said. "I then realized that to attract visitors, the first thing was to make the animals happy.

"Now, my son is in his 20s and loves talking about the zoo with his friends, which makes me very proud."

Wang Zhiqiang, producer of Tiny Cuties Great Events, a six-episode documentary series produced by Bilibili, the leading video community for young generation in China, said: "Many people first encounter animals on visits to zoos. According to zoo architect Zhang Enquan, over 600 million people in the world make such visits annually, and thanks to zoos, we have the chance to get a glimpse of wildlife."

Making the series, which premiered on Dec 29, took the creative team to nearly all the popular zoos in China from the middle of 2021 to autumn last year. Destinations included Nanjing Hongshan Forest Zoo, Shanghai Zoo and Xining Wildlife Park, Qinghai province.

Besides zoos, the team also visited animal rescue centers, including Longqiao Black Bear Care Center in the suburbs of Chengdu, Sichuan province, and Beijing Raptor Rescue Center.

The series focuses on issues such as natural and artificial breeding, and animal rescue and release by featuring the daily work of staff members at zoos and animal rescue centers. The concept of modern zoos, reimagining spaces for zoo animals, and the use of nature to help stage exhibitions at zoos are also explored in the documentary.

Wang said: "Making the series allowed us to better understand the relationship between animals and humans. We saw numerous young keepers who are passionate about their work. Many of them are highly educated and have returned to China after studying abroad.

"They take care of the animals and are also affected by them. The young keepers and the animals they look after can be quite similar in their behavior. For example, those who tend to amphibians are extremely quiet, while those who look after primates are very lively," Wang added.