Occurrence of the Endangered Keeled Box Turtle, Cuora mouhotii, in Southern Vietnam
Abstract
The keeled box turtle, Cuora mouhotii, is documented in southern Vietnam for the first time, extending the range of the species approximately 300 km southward. The southern population is morphologically similar to the subspecies C. m. obsti and occurs in sympatry with Cuora picturata, a species recently discovered in the wild for the first time. As C. mouhotii is known to hybridize with the closest living relatives of C. picturata (Cuora galbinifrons and Cuora bourreti), this finding allows for the possibility, on the basis of geography, that C. mouhotii and C. picturata may also hybridize in the wild.
Little is known about the turtle fauna of the Langbian Plateau of southern Vietnam. An early herpetological expedition to this area reported no information on turtles (Smith 1921). No turtle-focused field survey had been conducted there until the recent report of the Vietnamese box turtle Cuora picturata Lehr, Fritz and Obst, 1998 in the wild (Ly et al. 2011). Few records are available of wild turtles in Vietnam (Hendrie 2000; Stuart and Platt 2004), as most records are based on specimens found in trade and therefore have uncertain provenance (Stuart and Parham 2004; Fong et al. 2007).
The keeled box turtle, Cuora mouhotii Gray, 1862, is known to occur from northeastern India across southern China and southward through the Truong Son ( = Annamite) Mountains of Laos and Vietnam, as far south as Quang Nam Province in central Vietnam (Smith 1931; Bourret 1941; Iverson 1992; Fritz et al. 1998; Stuart and Platt 2004; Nguyen et al. 2009). Cuora mouhotii contains 2 described subspecies, C. m. mouhotii, occurring as far south as the northern Truong Son Mountains, and C. m. obsti Fritz, Andreas and Lehr, 1998 in central Vietnam (Fritz et al. 1998). The species is listed as Endangered in the IUCN Red List of Threatened Species due to overexploitation (IUCN 2012). Cuora mouhotii is harvested across its range for local consumption and sale for food, traditional medicine, and pets (Hendrie 2000; Stuart and Timmins 2000; Cheung and Dudgeon 2006; Chen et al. 2009; Gong et al. 2009).
Field surveys for wild C. picturata were carried out by one of us (T.L.), 3 local villagers, and 3 hunting dogs on the Langbian Plateau at Deo Ca Protected Forest, Phu Yen Province, Vietnam during 6–10 January 2011 (Ly et al. 2011) and at Vong Phu Mountains, Dak Lak Province, Vietnam during 31 August–7 September 2011. At Deo Ca on 7 January 2011, we encountered a live, wild, female individual of C. mouhotii approximately 550 m from 2 wild C. picturata (Ly et al. 2011). The C. mouhotii was found at 1245 hrs, in a rock den in a moist evergreen forest at lat 12°51′09.35″N, long 109°18′48.86″E (WGS 84 datum), at 452 m elevation (Fig. 1). It was 240 g in weight, 119 mm in carapace length, and 92 mm in carapace width. The turtle was photographed (Fig. 2) and released at the site of capture. On the previous day, we also saw 7 live C. mouhotii in the possession of a local hunting group at lat 12°51′32.51″N, long 109°18′37.37″E during our field survey within the Deo Ca Protected Forest, but these were not photographed or measured. At Vong Phu, we also observed, measured, and photographed 1 male C. mouhotii on 2 September 2011 and 1 female C. picturata on 3 September 2011 in the possession of local hunters encountered in the forest near lat 12°44′0.95″N, long 108°56′29.52″E (Figs. 1 and 3).
Citation: Chelonian Conservation and Biology 12, 1; 10.2744/CCB-0964.1
Citation: Chelonian Conservation and Biology 12, 1; 10.2744/CCB-0964.1
Citation: Chelonian Conservation and Biology 12, 1; 10.2744/CCB-0964.1
The discovery of C. mouhotii on the Langbian Plateau extends the known range of this species approximately 300 km southward from Quang Nam Province, Vietnam (Nguyen et al. 2009). Elsewhere, male C. mouhotii are known to hybridize with females of Cuora galbinifrons and Cuora bourreti (Parham et al. 2001; Stuart and Parham 2004; Shi et al. 2005) and produce hybrid turtles that were originally named as a new species, Cuora serrata Iverson and McCord, 1992 (Iverson and McCord 1992). No hybrids of C. mouhotii and C. picturata have been reported (Parham et al. 2001; Stuart and Parham 2004). However, by extending the known distribution of C. mouhotii southward into the newly discovered range of C. picturata (see Ly et al. 2011), where the 2 species occur in syntopy, we show that the wild hybridization of these 2 species on the Langbian Plateau of southern Vietnam is at least possible on the basis of geography. The record of C. picturata at Vong Phu also provides a fourth locality for this species (Ly et al. 2011), although it was found there in the possession of local hunters in the forest and not seen in the wild.
Morphologically, the new population in southern Vietnam resembles the subspecies C. m. obsti from central Vietnam by having a rounder shell, a plastron with a radiating black pattern on each scale, and reticulating lines on the head (Fritz et al. 1998), and we tentatively refer the new population to this subspecies. Although there are no apparent differences in morphology between the new population and C. m. obsti based on our limited field observations, morphological and genetic studies in the laboratory may reveal more. Cuora mouhotii has a concordant geographic distribution with the C. galbinifrons species complex in Vietnam, with C. m. mouhotii and C. galbinifrons Bourret, 1939 occurring in the north, C. m. obsti and C. bourreti Obst and Reimann, 1994 (Obst and Reimann 1994) in the center, and the new population of C. mouhotii and C. picturata in the south (Stuart and Parham 2004; Ly et al. 2011). This suggests that the southern population of C. mouhotii might prove to be a distinct evolutionary lineage if C. mouhotii has responded to the same diversification factors in the landscape that has generated 3 evolutionary lineages in the C. galbinifrons species complex. Further study on morphological and genetic variation in C. mouhotii is warranted.
The discovery of a new population of C. mouhotii provides a new opportunity to conserve this endangered species in the wild. Unfortunately, C. mouhotii is threatened in southern Vietnam by deforestation and overharvesting for sale into the wildlife trade. Although Deo Ca and Vong Phu are protected by law, large areas of primary moist evergreen forest in the vicinity of these localities are being converted into tree farms that are unsuitable for wildlife, and local communities still hunt within Deo Ca and Vong Phu. Turtles have been harvested and sold by these communities as a livelihood activity for decades. Effective in situ conservation management of C. mouhotii will require enforcement against wildlife poaching and trading, as well as economic incentives for the local communities to protect the forest and wildlife.
Map illustrating turtle localities at Deo Ca Protected Forest, Phu Yen Province (white circle), and Vong Phu Mountains, Dak Lak Province, Vietnam (black circle).
Cuora mouhotii found in the wild at Deo Ca Protected Forest, Phu Yen Province, Vietnam. (A) In situ in microhabitat, (B) lateral view, (C) dorsal view, and (D) ventral view. Photographs by Tri Ly.
Cuora mouhotii and Cuora at Vong Phu Mountains, Dak Lak Province, Vietnam. (A) Dorsal and (B) ventral view of C. mouhotii, and (C) dorsal and (D) ventral view of C. picturata. Photographs by Tri Ly.
