The Conservation Status of Gibbons in Vietnam - Gibbon Research ...

The Conservation Status of Gibbons in Vietnam6.2 Summary of Status and Distribution in Vietnam6.2.1 Change in Status Since 2000Considerable new information on the taxonomy, distribution and ecology of N. siki in Vietnam hasbeen documented since the first Vietnam status review of gibbons (Geissmann et al. 2000).Nomascus siki was previously thought to occur in five provinces of north-central Vietnam, withnorthern and southern distribution limits thought to be the Ca River (Nghe An Province) and BachMa National Park (Thua Thien Hue Province) respectively (Dao Van Tien 1983; Geissmann et al.2000; Pham Nhat 2002). However, as a result of its elevation to species status and the splitting of anew central Vietnamese form (N. annamensis), its national distribution has been reduced to asmall region from Ha Tinh Province in the north to approximately the Thach Han River in thesouth (Van Ngoc Thinh et al. 2010c). The northern distributional limit of N. siki in Vietnam isunknown; the boundary region between N. siki and N. leucogenys appears to lie near Khe NetProposed Nature Reserve (Quang Binh Province) and Ke Go Nature Reserve (Ha Tinh Province),but the taxonomic status of the gibbon populations in these sites has not yet been determined(Van Ngoc Thinh et al. 2010a; Van Ngoc Thinh et al. 2010e).Since 2000, surveys for N. siki have been conducted in all sites in Vietnam where the species isknown to occur. Despite this, few conservation activities to protect remaining populations havebeen initiated. There is currently no dedicated protection or monitoring of N. siki in any site inVietnam. Uncontrolled hunting and habitat loss remain the greatest threats to N. siki. The speciesis in decline throughout its national range and there are no clear instances of conservationsuccess, either directly or as part of other biodiversity initiatives. Populations in Phong Nha-KeBang National Park may be stable, but this is unclear as baseline data for some parts of the parkhave only become available in recent years.6.2.2 Key Sites for ConservationTwo large forest complexes, the Phong Nha-Ke Bang National Park-Truong Son State ForestEnterprise and Khe Giua State Forest Enterprise-Bac Huong Hoa Nature Reserve complexes,support most of the known N. siki population in Vietnam. Collectively these sites extend betweenQuang Binh and Quang Tri Provinces, and are contiguous with forest in Laos where N. siki occursincluding Hin Nam No NPA. Other populations comprise scattered and isolated groups indesignated and proposed nature reserves. Khe Ve and Giang Man Proposed Nature Reservessupport small populations, but they are isolated by rural development and cultivation.6.2.3 ThreatsHunting continues to be the principle threat to N. siki in Vietnam and is resulting in the gradualextirpation of the species in some sites. There is no data on the numbers of individuals huntedover time and trends in hunting of this species (stable, increasing or decreasing) are unknown. It isclear that efforts over the past decade to control the hunting of gibbons (and much other wildlife)in Vietnam have largely failed. In most sites, the impact of hunting has been compounded byongoing loss and degradation of forest habitats, as well as the very small size and isolation ofmost populations. Remnant gibbon groups are vulnerable to genetic depression due to lownumbers of individuals and stochastic events such as disease and extreme weather events.6.2.4 Ongoing Conservation ActionsConservation efforts of the Forest Protection Department to manage forests and reduce illegalhunting/trade of wildlife has contributed important (but unquantifiable) aid for the survival of N.siki, however, to date, most N. siki populations receive little protection and continue to be hunted.Relatively extensive primate conservation efforts in Phong Nha-Ke Bang National Park includingconservation awareness, primate rescue and research have been supported by severalinternational organizations (Cologne Zoo, Frankfurt Zoological Society, FFI, KfW and WWF).57