Endangered species secured in zoos
Endangered animals’ best chances of survival and saving them from extinction are in the zoos. The South China tiger is one such example.
Ex situ conservation is possibly the last measure to conserve endangered species, saving the animals from extinction within a short period of time while helping the population to grow, and eventually reintroducing them in the wild.
“The first and foremost condition in ex situ conservation is to ensure the animal’s survival. We have a lot of work to do, including reducing stress, creating proper environment and the right food and nutrition as well as medical support,” said Pei Enle, director of Shanghai Zoo, who was previously the director of Shanghai Wildlife Conservation Management Station.
For endangered animals that still have wild habitats, in situ conservation is carried out to help their population to grow.
Helping the wild animals to adapt to a lifestyle in zoo is not an easy task. Besides feeding them correctly, zoos must enrich their experiences to ensure they are healthy without strange and stiff behavior that normally occurs in captivity.
Artificial breeding technology is the key in ex situ conservation. Scientists must solve the problems of difficulty in pregnancies and low breeding rate while keeping the cubs alive in artificial environment.
For example, pandas usually can only breed one cub in the wild and have pretty low odds of survival. But when they are in captivity and get help from humans, twins are more likely and also have better changes to survive.
“Zoos also have the job to educate everyone on not using wildlife related products and the reasons behind their endangered status, which will help the habitat conservation works because people will understand better,” said Pei.
The final goal of ex situ conservation is not keeping the animals alive in zoos, but releasing them back to their home in the wild, so they will grow naturally.
Pei Enle, director of Shanghai Zoo.
South China tiger
The South China tiger used to reside in regions south of the Yangtze River. In the 1970s, they were regarded as vermin because of their aggressive nature, and the population soon died out in the wild.
Zoos in China started to keep the South China tigers in the 1950s. In 1995, there were 47 tigers of two pedigrees, one Shanghai and one Guiyang.
Shanghai Zoo led the conservation project to protect the South China tiger. DNA analysis was done on the 47 tigers to determine the purity of pedigree. All the zoos that housed the tigers across China joined the project and followed the strict rules in managing the population.
“According to ecology including the demographic information of the tigers as well as genetic characteristics, we started to make plans for pairing and relocating them every year, trying our best to avoid inbreeding and help the species survive longer,” Pei said.
They invited experts from the US to conduct health checks and sperm analysis of the tigers as well as impart trainings on animal nutrition.
In the beginning, there was a serious imbalance of gender and age among the 47 tigers. With 22 years of hard work, now the age pyramid has been restored, and the sex ratio has reached 1:1.
“Work is still being done to prepare the possible return of tigers in the wild or protect them in the wild on a larger scale. That’s the ultimate hope,” said Pei.
After 22 years of ex situ conservation project that was led by Shanghai Zoo, the number of South China tiger in captivity has grown from 47 to 184.
Oriental stork
This large, white bird with black feathers became an endangered species due to loss of its habitat and hunting. Their population was almost extinct in the wild and now breeds mostly in captivity.
In 1982, Shanghai Zoo successfully bred oriental stork for the first time. A research project to improve the reproductive rate of the bird was carried out, even winning the second prize at the Shanghai Advanced Science and Technology award in 1996.
“The oriental stork is a determinate layer like chickens, which means the females usually produce a fixed number of eggs in the clutch. So we can take away the eggs and hatch them artificially,” Pei said.
The oriental storks usually lay two eggs in a clutch. In order to increase the numbers of eggs for artificial incubation, the staff takes away one egg, forcing the bird to produce another one.
The zoo usually repeats this process to get four eggs to hatch artificially, while let the bird hatch two naturally, taking the total number of eggs to six.
The artificial incubation is not an easy task as well. There’s specific humidity, temperature and length involved in it.
When the hatchlings arrive, they must be fed the same way their parents would — that is the predigested fish. So the feedstuff must be adjusted to imitate that process.
The fears about the oriental stork’s extinction is now gone. The zoo is now controlling the population in captivity, and they can be trained before they are released in the wild.
“Every animal in the zoo — protected species or otherwise — has a role, whether it’s for continuing the species, exchange with other zoos or educating the public,” said Pei.
The oriental stork is a large-sized bird that was endangered in the wild.
