Some Observations on Anurans in China
Stephen
Aldridge
May, 1999
Scientists recognize the presence and health of frogs and toads as an important indicator of the overall health of an ecosystem. For the last several years all kinds of volunteer groups have been organized for the purpose of monitoring frog populations in countries all over the world. Mutant frogs with disfigured bodies, missing or extra limbs have been in the news of late with much speculation on the cause of the mutations.
With frogs as an indicator of the health of the environment borne in mind, a search for frogs, toads, and other amphibians was made on hikes in over 10 cities and counties in China in May of 1999. The text that follows is divided into two parts, the first of which might be more favorably regarded by real herpetologists, although written by a dilettante, an amateur, one who “takes delight in” frogs. The second paragraphs, the city section, are limited in that only one species was positively identified.
The first group of frogs (Pelobatidae) were found at 9000 ft on Paoma Shan above Kangding in Sichuan about 260 miles to the west of the capital of Sichuan at Chengdu. A cluster of mating Scutiger ruginosus was found in a catch-basis. Nearby, in a tank that had become a place to throw trash, but otherwise an ideal place to collect rain water, were piles of mating Scutiger, building the classic “frog pyramids” and hooting at one another. The fact that this species can live and thrive with no visible deformities in such an aesthetically unpleasing environment points to the robustness of the species but also to a frequent assault to aesthetic sensibilities to lovers of pristine forests and clean ponds. All over China and including Tibetan areas the environment is frequently trashed. One can walk for several hours on a clean, quiet and utterly delightful forest trail, past rhododendrons and other plants in bloom, and then come upon a popular picnic spot to find it littered with paper, plastic bottles, wrappers. The concept of “pack it in, pack it out” has yet to be impressed on the Chinese popular environmental imagination. A true environmental movement has not set in China yet. However, the presence of frequent TV commercials against discarding tissues or soda cans is a hopeful sign. With sadness at the fact that a new bunch of frogs would grow up in trash, the search continued.
Scutiger ruginosus at Paoma Shan
At 12,300 feet at Dzogchen in Dege County, the same species of frog was found. Also found was Scutiger mammatus. This species has very small rows of spots along the sides of its back and may be what the “spotted Dege frog” referred to by several writers. The latter looks more “frog-like” than its cousin which many people would call a toad because of its bumpy skin. This second sighting was in a clean environment. The streams were fed right off the Chola Glacier 2000 feet above the Rudam Kyitram valley. A visit to caves below the glacier revealed more catch basins and small ponds with plenty of tadpoles. The presence of frogs in the area has been noted by Patrul Rinpoche (1807-87) who lived in the area and wrote his Zunzang Lamei Zhalung, translated into English as Words of My Perfect Teacher while living in one of the caves right above one of the larger frog ponds.
In the town of Dege, over the Chola Mountain range and down 1000 feet, a search was made for frogs or toads of any kind. Many children and wandering religious mendicants attested to the existence of frogs in the Zi-chu River below the town and in streams in valleys leading into town from the south, but no frogs were found. The non-discovery of any frogs in Dege must be tempered by the fact that only 6 miles of two riparian systems were followed upstream from the town of Dege. The frog habitat has undoubtedly been disturbed by gold mining in the Zi-chu river, although the old sand sifting technique is used, not mercury extraction methods. There is a lot of digging and movement of earth in the riverbeds. Not finding frogs at Dege was a disappointment to this writer as the “spotted Dege frog” has been mentioned in several books as a particularly fun frog to play with. It is the opinion of the writer that the underlying problem in Dege is the destruction of the frog habitat by sewage and trash in the central feeder stream running down from the south.
The conclusion for observations of frog health in Kham is that frogs seem to be doing ok the farther away from civilization one goes. The more severe the dumping of trash and sewage into the river or stream, the greater the impact on at least the two species observed. Critical to the Scutiger is absence of disturbance of the eggs and adequate still, clean water for the tadpoles to reach maturity. At Dzogchen, the gentler the slow, meandering side stream, the more tads, and the same for any pond. If too many yaks or other animals got into a pond and the pond was the primary catch basin in an area, animal excrement would invariably result in a dead pond, supporting no frogs.
In general, however, far fewer frogs were found in environments that would normally be suitable for them. The impact of mining, garbage, and sewage are obvious contributing factors in the decline of frog populations. Other factors mentioned by biologists would include destruction of forest habitat and loss of biodiversity in previously heavily forested areas. With the recently mandated order to cease timber cutting in Garze Prefecture, perhaps the frogs in that part of Kham will have a better chance at survival.
Across China, in a second exploration of nature, in Jiangsu Province, in the forests above Nanjing, an unidentified wood frog was found and lots of tad poles in streams and public parks.
In Guangzhou, the American bullfrog (Rana catesbeiana) was seen in the animal street market. One specimen was in fact observed hopping his way down the street. Smaller frogs that used to be sold by the basketful were not seen at all. The only species was the plain old, dumb American bullfrog. It may well be that the introduction of this frog, and I am conjecturing that they came from big commercial frog farm operations in Taiwan, which, incidentally, supply most of the frogs selling for $3.69 per pound in Oakland and San Francisco at the moment, has contributed to the demise of the smaller species. Rana catesbeiana is notorious for its cannibalistic personality. This writer, a lover of frogs since childhood, has been forced to recognize the extremely harmful results of the introduction of rana catesbeiana on the native California red-legged and other species of frog throughout the Northwest. The American bullfrog does not appear to ever be in the mood for compromise. Philosophically speaking, the only solution to the problems caused by this species seems to rest in eating the source.