Summary of the Core Content
This news article reports on the successful reintroduction of the Shanghai-native spotless rain frog (formerly known as “Yugagua”) into the wild after more than 20 years of disappearance. On May 31, 2025, 120 frogs were released into their natural habitat as part of an experimental program. The article not only discusses the unique significance of this species and the reasons for its decline but also details the efforts made by conservationists to prepare for the release, including the transformation of an ecological farm, the selection of safe pesticides, and the use of artificial breeding methods. It also covers the plans and challenges involved in reestablishing the frog population.
I. The Unique “Yugagua” from Shanghai: Why Did It Disappear for Over 20 Years?
The spotless rain frog is the only amphibian species native to Shanghai that has been scientifically identified and named. It was once abundant in the rural rice fields, with villagers saying they could catch enough frogs to feed ducks in a single night. However, it suddenly disappeared around two or three decades ago due to several factors:
1. Habitat destruction: Urban expansion has led to the loss of wetlands and farmland, and waterways have been hardened with concrete, leaving no suitable places for the frogs to overwinter.
2. Changes in agriculture: Small farms have merged into larger plots, with a shift towards monoculture (such as rice or fruit trees), eliminating the mixed environments that the frogs preferred (rice fields, grasslands, and bamboo forests).
3. Excessive use of pesticides and fertilizers: Pesticides and fertilizers have contaminated the water and soil, harming the frogs.
4. Other threats: Climate change, competition from invasive species like the black-spotted frog, and the frog being traded as a pet have also contributed to its decline.
II. The 120 Frogs Returning to the Rice Fields: Ten Years of Preparation for the Reintroduction Experiment
This release was not a casual decision; the team had been preparing for ten years:
- Raising frog offspring: In 2023, tadpoles were obtained from Chuzhou, Anhui, and raised in both laboratory and outdoor enclosures.
- Transforming the ecological farm: A traditional pesticide farm in Fengxian was converted into a “frog paradise” by planting native plants and converting dry land back into rice fields while preserving existing waterways, slopes, and forests.
- Testing safe pesticides: Commonly used pesticides in Shanghai were tested to identify those that are harmless to the frogs.
- Monitoring reproduction: The team has been observing the frogs’ mating behavior and collecting eggs from the wild for breeding in the laboratory (since survival rates in the wild are low).
On the day of the release, more than 80 nature enthusiasts and children helped return the frogs to their natural habitat. Some frogs immediately jumped into the water, while others climbed onto the banks; the children eagerly took photos to document the event.
III. The Ecological Farm Designed for the Frogs: What Changes Were Made?
This 100-acre farm is designed specifically to support the rain frogs:
- Mixed environments: It includes rice fields (essential for reproduction), as well as dry land, waterways, slopes, and forests, providing the perfect habitat for the frogs to hide during the day and hunt at night.
- Safe pesticides: Only harmless pesticides are used to minimize harm to the frogs.
- Native plants: These plants attract insects, which are a food source for the frogs, and also provide them with shelter.
- Gradual transition: The frogs are first raised in enclosures to acclimatize before being released into the wild, increasing their chances of survival.
Now, various frog calls can be heard on the farm at dusk, indicating that the environment has indeed improved.
IV. Can the Rain Frogs Re-establish a Population in Shanghai? And What Are the Challenges?
The team is optimistic about the future, but there are still several challenges:
- Survival rate: Not all of the 120 released frogs may survive, but the team has mastered artificial breeding techniques to continuously supply new individuals.
- Expanding the release effort: More frogs will be released this autumn.
- Community involvement: Farmers need to reduce the use of pesticides and fertilizers; more people should join the conservation efforts (for example, by using eco-friendly farming methods that benefit both crops and the frogs).
- Long-term monitoring: It is necessary to track the survival of the released frogs and adjust conservation strategies accordingly.
Guo Taoran, a conservation expert, stated, “After ten years of effort, we have finally taken this step toward reintroducing the rain frogs. In the next few years, it is very likely that they will be able to establish a population in Shanghai again.”
This news story is not just about the rain frogs; it also raises the question of how cities can coexist with nature. Protecting a small species is a testament to the need for ecological restoration and a reflection on our lifestyle. Hopefully, these adorable “Yugagua” will indeed return to the rice fields of Shanghai, and their calls will once again fill the air at night.