Li Zhisai (left) and Zhang Shuai, raptor rehabilitators from Beijing Raptor Rescue Center, release a rescued short-toed snake eagle into the wild at Wild Duck Lake Wetland in Beijing's Yanqing district on Oct 17. [Photo provided to China Daily]
On the afternoon of Oct 17, under a canopy of gray clouds and intermittent drizzle, a team of rehabilitators from Beijing Raptor Rescue Center ventured to a patch of grassland nestled within Wild Duck Lake Wetland in Beijing's Yanqing district.
Nearly 100 kilometers north of downtown Beijing, the park served as the backdrop for the release of a rescued short-toed snake eagle (Circaetus gallicus) back into the wild.
Li Zhisai, a raptor rehabilitator at the center, and her colleagues released the raptor — which had a pale colored underside and a dark brown head. Being outside a cage for the first time since May last year, the eagle soon flew away into the cloudy sky.
The release of the snake eagle marked yet another milestone for the center. Established in December 2001 through a collaborative effort between Beijing Normal University and the International Fund for Animal Welfare, the institution stands as the country's first facility dedicated to the rescue and rehabilitation of birds of prey. Over the years, it has received and treated over 6,000 raptors and organized more than 1,000 wildlife conservation and environmental education activities, according to Zheng Zhishan, manager at the center.
Among the many successful rescue stories, the bond forged with this short-toed snake eagle holds a special place in the hearts of Zheng and her team. This remarkable bird represented the 40th raptor species to find refuge at the center in its 23-year history.
Identified as No 230501 within the center, the eagle became a focal point of the team's efforts, requiring over a year of dedicated care and innovative treatments, including the intricate procedure of feather grafting.
"Compared to the many raptors we've nurtured back to health, No 230501 demanded an extraordinary amount of our time and expertise," Zheng said.
Chance sighting
In the early morning of May 1 last year, wildlife photographer Zhang Ge, while bird-watching on the north shore of Guanting Reservoir, which is near Wild Duck Lake, noticed a raptor on the ground behaving unusually, surrounded by a congregation of magpies.
Zhang told Beijing Youth Daily that with 15 years of bird-watching experience he immediately recognized the bird as a short-toed snake eagle, a raptor comparatively rare in Beijing. Despite magpies typically driving away raptors, the eagle, with disheveled feathers, did not take flight during the confrontation but instead hopped around on the ground, seeking refuge in nearby reeds.
Approaching cautiously, Zhang managed to scare off the magpies and found the eagle lying on the ground, unable to fly due to injuries. Wearing gloves, he covered the eagle's eyes with a cloth bag, gently picked it up and placed it in his car.
The eagle showed no resistance during the encounter, indicating its weakened state. By around 10 am, Zhang arrived at the center in Beijing Normal University and handed the eagle over to the rehabilitator, Zhou Lei.
In the past, Zhang had encountered injured birds of prey and tried to send them to rescue centers, but the birds died on the way. This was his first close encounter with a raptor that was rescued successfully, and he hoped that through professional care, the eagle would soar once again.
In China, raptors are classified as first or second-class wildlife under State protection, playing a crucial role in maintaining ecological balance. Beijing serves as both a habitat for raptors and an important stopover site on their migration routes.
The short-toed snake eagle, also known as the short-toed eagle, is a medium-sized raptor that can be found in Europe, Asia and Africa. It is a rare migratory bird in Beijing. It typically inhabits hilly areas, open grasslands or areas with sparse trees, feeding mainly on reptiles such as snakes, lizards and frogs, occasionally preying on small rodents such as wild rabbits and mice.
"When I saw the eagle, my heart sank — it was barely moving, with very weak vital signs," Zhou recalled. "Thankfully, its eyes were open, and although its claws were slightly shorter than those of similar-sized raptors, it could still move slightly."
Zhou and her colleagues immediately gave the bird a comprehensive health check. Upon examination, they found that the eagle was malnourished, with underdeveloped chest muscles and several soft tissue injuries. Its beak was unusually long, indicating possible previous human captivity.
"Most concerning were the few remaining primary flight feathers — only about one and a half primary feathers were left out of the original 20," Zhou said, adding that some feathers were broken at the base, while others were broken in the middle, rendering it unable to fly and hunt effectively.
On the first day, they treated the bird's injuries on its breast and a toe, and cut short an unusually long part of its beak.
Many difficulties
With very few of its primary flight feathers remaining, the bird needed molting to facilitate the growth of new feathers. As a result, the rehabilitators initially decided just to provide enough nutrients to promote feather growth.
However, they soon met the first challenge — the bird refused to eat.
"We offered the bird a variety of food such as rats, mice, bullfrogs and chicken meat, trying to provide as rich a diet as possible," Zhou said. "But it refused to eat any of it."
To sustain its life, she and her colleagues gave infusion treatments and force-fed the bird, and gave it drugs with each feeding to improve digestion. Despite their efforts, the bird's weight dropped from its initial 1,454 grams upon arrival to a low of 1,274 grams. The situation persisted for over 20 days, during which it only very occasionally ate voluntarily until the issue was significantly improved on May 27.
Just as its eating habits were starting to improve, a second new issue arose. Twenty days after arriving at the center, its blood test showed a sudden increase in its white blood cell count.
Since its injury on the keel bonea major bone running along the front of its chest — had not yet healed, the rehabilitators treated the bird with antibiotics. A week later, its white blood cell count dropped to the normal level.
Over the following month, they continued to monitor its blood tests, during which time its wound healed, and its blood stabilized.
During a health check on June 26 last year, a new feather began to grow, pushing out the old feather, a process known as molting. The new feather that emerges is called a blood feather.
After resolving the first two issues, Zhou said, the biggest problem for the eagle was feather damage. Extensive feather damage can only be resolved through natural molting, and the appearance of blood feathers indicated that the eagle had started molting.
By October last year, the bird's flight and tail feathers had mostly been replaced.
However, before Zhou and her colleagues could celebrate, its newly grown feathers began to deteriorate in November last year, and this damage continued until the end of last year, with its feathers essentially reverting to their condition when it arrived at the center.
Due to the significant loss of flight feathers, Zhou explained, the new feathers grew out alone, lacking the protection of other feathers, making them prone to breakage.
"Any raptor unable to grow and maintain normal flight feathers cannot be released back into the wild," Zhou said. "We found ourselves in a dilemma where, aside from providing it with adequate nutritional support, we were unsure of what else we could do. Our only hope lay in its next molting season."
Feather grafting
Just when they felt helpless, a turning point arrived.
In March, Neil Forbes, a British veterinary expert, visited the center for a tour. The rehabilitators consulted him regarding the feather issue with the eagle, and he proposed a treatment plan: first, to perform protective feather grafting, where grafted feathers would protect the new growing feathers; second, to regularly add vitamin H to its food to promote feather growth.
With a solution in hand, they immediately took action.
As it was the first short-toed eagle received at the center, their "feather bank", where they collect feathers from raptors that couldn't be saved in order to graft them onto other birds, did not have short-toed snake-eagle feathers.
As a result, they used feathers from owls, falcons, buzzards and large raptors for the grafting operation and regularly added vitamin H to its diet.
In March, they performed "protective feather grafting" for the eagle, attaching six feathers to its left wing and nine feathers to its right wing, Zhou said. After the feather grafting, the eagle initially showed some discomfort in the enclosure and even broke off a newly grafted feather shortly after. "But it quickly regained its composure," she said.
As expected, during this year's molting season, the grafted feathers helped the new feathers grow in good condition. In August, Zhou told Beijing Youth Daily that the eagle had grown 15 new flight feathers, most of which were growing well. The eagle could fly within the enclosure. As the new feathers gradually filled in, only about three old feathers remained grafted.
"The process of new feathers replacing the old is somewhat akin to humans shedding baby teeth and growing adult teeth," Zhou said.
The bird's weight reached 1,778 grams on Sept 26.
Zheng said: "The autumn wind is blowing and it is right during the migration season for birds. The Wild Duck Lake area teems with diverse wildlife and offers an ideal environment for the bird to readjust to life in the wild. We hope it can soon catch the wind to embark on its journey."
