Tuesday 28 June 2022

The Critically Endangered Chinese Pond or Yellow Terrapin. Hong Kong in the 1960s

I noted when I reviewed the new book on the freshwater chelonians of Hong Kong that the Chinese Pond Terrapin, Mauremys mutica does not appear. Those that were once found there were classified as Introduced because Hong Kong was said not to be within its known range. However, that is clearly not now the case, judging by the distribution map shown in the IUCN Red List (where it is called the Yellow Pond Turtle). I suspect that it should be considered as having been extirpated in Hong Kong by collection and habitat loss but occasionally restored if not sustainably by the release of captive specimens from the food markets.

In the wild this species has suffered a catastrophic decline in numbers over the past few decades. An 80% fall in three generations across Vietnam and China was IUCN’s estimate in 2018. It is now marked Critically Endangered. The Wikipedia article (which has a dreadful photograph of a stuffed specimen in Japan) provides a list of references which illustrate both the complexity of what might not be a single species and of difficulties of conservation through captive breeding and release of stock from farms. The species, along with many others, is farmed in China and there are examples of all sorts of weird hybrids turning up in captivity and in feral populations.

Mauremys mutica (then known as Clemmys mutica) was a regular in the wet markets of Hong Kong in the 1960s. The one I show here (photographed on the roof of the now-demolished Northcote Science Building of the University of Hong Kong) was bought in a Kowloon market by a lecturer, whose name I am still trying to remember, at what was then Hong Kong Baptist College, in 1966 or early 1967. She then released it in the wild in the New Territories.

The account in Karsen, Lau and Bogadek’s second edition of Hong Kong Amphibians and Reptiles published in 1998 described what was then known:

May be regarded as introduced. As an indirect result of the pet trade and traditional medicine trade, occasional specimens escape or are released. One specimen was found on Cheung Chau, having almost certainly escaped from a nearby temple where numerous species of terrapins were kept. Additional specimens were found in the vicinity of Shing Mun and Tai Tam Reservoirs, Sai Kung and Shek Kong areas. It is doubtful whether this species is part of Hong Kong's native fauna since these records lie outside the historic range, and there has been a recent surge in records in areas frequently visited by people.

All sorts of questions spring to mind. Did the ones released ever breed? Have they now all gone? It is perhaps worth noting that in the areas mentioned, Red-eared Sliders, the ubiquitous pet terrapin and also farmed in China for the human food market, are now commonplace. Have they outcompeted these as well as other native-to-China if not native-to-Hong Kong species?

Dire straits is the only description I can think of for status of the chelonian populations of China.

Sunday 26 June 2022

A Field Guide to the Turtles of Hong Kong by Adam Francis. 2022, ISBN978-988-74587-2-2

A welcome package from Hong Kong arrived. It contained the new, short (75-page) book on the freshwater chelonians of Hong Kong. This volume, written and self-published by Adam Francis, complements his earlier volume on the snakes of Hong Kong which appeared in 2021.

The book is aimed at helping and encouraging those who look for reptiles in the wild—an increasingly popular activity in Hong Kong, with both books spin-outs from the author’s YouTube channel SnakeID TV, a must watch for anybody interested in Hong Kong wildlife, and its associated website, hongkongsnakeID.com. Like the book on snakes this one is lavishly illustrated even if the printing of the photographs is, to my eyes, too dark.

The book is a leap forward from the nearly 25-year old second edition of Hong Kong Amphibians and Reptiles by Karsen, Lau and Bogadek. There are two reasons for this. The first is the vastly increased number of field observations and photographs. The second is that it covers the increasing numbers of introduced species that have appeared in the wild.

One example of the leap forward in knowledge is the case of Mauremys (formerly Ocadia) sinensis - the Chinese Stripe-necked Terrapin. The standard story (in the Karsen, Lau & Bogadek book) stated that the only specimen known from Hong Kong was a single individual dug up from a dried-out pond in Stanley Internment Camp during the  Second World War. There was also a possible sighting in the wild in 1980. By contrast, Francis writes that they are found all over Hong Kong in nearly every freshwater environment. However, I have re-read Geoffrey Herklots’s account in which he described and drew the individual found in Stanley and I suspect his story has been misinterpreted because he actually wrote of this species as ‘less common’ than Reeves’s Terrapin. In other words it was known from Hong Kong before the one from Stanley turned up to feed a hungry internee in Stanley.

Throughout, Mauremy sinensis has been considered an Introduced species in Hong Kong, a classification maintained by Francis. However, Hong Kong is within its known range and the IUCN Red List has it tagged as ‘Extant and Introduced’ in Hong Kong. My best guess is that it is native to Hong Kong but was reduced to very low numbers by collection for human consumption.

The problem of deciding what species are native to Hong Kong is an old one. That is because there is a long history of live freshwater chelonians being imported for human food and for traditional Chinese medicine. Some of these, as well as some individuals caught locally, escaped or were released. The trade in China has been boosted by farming but, overall along with severe loss of habitats, has done so much damage that a number of species are now classified as Critically Endangered or Endangered. In more recent years, there has also been trade in pet chelonians, with the late 20th century worldwide boom in ‘baby turtles’ from the USA being evident from the presence of large numbers of Red-eared Sliders in the ponds and lakes of public parks and reservoirs. A walk down the fish and pet shops on Choi Tung Street in Kowloon, presents a bewildering display of young chelonians of many different species from all parts of the world and it is hardly surprising that adults are released into bodies of freshwater, or in the case of tortoises, to the forests and parks. Some surprising additions to the Hong Kong fauna have appeared; the Elongated Tortoise (Indotestudo elongata) is one example.

Adam Francis provides information for the identification of 17 species. Of these he marks 11 as Introduced (including Mauremys sinensis, mentioned above). including 3 from North America, and 1 from Africa. Of the native (or at least those in which Hong Kong would be included as part of their natural range or forming a relatively small extension) 6 by Francis’s reckoning, 7 by mine. 4 are classified by IUCN as Critically Endangered, 2 as Endangered and 1 as Vulnerable. What an enormous decrease in wild populations there has been in the past 50 years. In the 1960s, all the native species were for sale in large numbers in the markets of Hong Kong.

One species that does not get a mention in the book is Mauremys mutica or Chinese Pond Terrapin. Although recorded in earlier years and sold in the live food markets, it was regarded, again, as Introduced. However, the current distribution map in the IUCN Red List shows that Hong Kong is well within its natural range. Has it now disappeared (even if from Introduced individuals) from Hong Kong? It has declined throughout its range to the extent it is now also classified as Critically Endangered.

In recommending this book to anybody interested in Hong Kong reptiles or chelonians in general, it does come with a few problems for the British English-speaking world. The title, A Field Guide to the Turtles of Hong Kong, would suggest it concerns marine chelonians. ‘Freshwater Turtles’ would signify its coverage even if freshwater turtles to Brits are terrapins (ironically an Algonquin word adopted in British usage for ‘water-tortoises’). In the book, the common names used for some species include ‘terrapin’ while others include ‘turtle’, for example, Chinese Striped Terrapin; Beale’s Four-eyed Turtle.

One real error is the eponymous Reeves’s Terrapin which is shown throughout as ‘Reeve’s Terrapin’. John Reeves (1774-1856) who sent the specimens to London and worked largely in Macau as Inspector of Tea for the East India Company, might be be rotating in his grave.

The arrangement of the book also seems rather strange. The plates come first while the ‘introduction’ (which includes a section on poaching and protection) is at the end. It would also have been useful to have a list of synonyms which would make looking for or cross-referencing earlier publications easier.

The book costs HKD 220 (approximately £23). I have only seen it for sale by booksellers in Hong Kong and the author’s website (with the latter restricted to batches of ten).

Herklots GAC. 1951. The Hong Kong Countryside. Hong Kong: South China Morning Post.

Karsen SJ, Lau M W-N, Bogadek A. 1998. Hong Kong Amphibians and Reptiles. Second Edition. Hong Kong: Provisional Urban Council. ISBN 962-7849-05-7