Civette d'Owston

The total population of Owston's Civet will always have been much smaller than that of most other mainland South-east Asian civets because it has such a small geographic range. There is insufficient baseline information to define the precise range and even the general abundance in the era before trade-driven hunting began to accelerate steeply in the 1980s with the increasingly wide deployment of cable-snares in long lines linked by brushwood drift fences. Therefore, its population trend needs to be inferred from trends in habitat and in hunting (types, distributions and intensities), based on a hypothesised geographic and ecological distribution, itself inferred from habitat (from which the known precisely located records come) and distributions of ecologically restricted co-occurring species.

Severe declines probably started in the early 1990s, Around this time, evidence suggests other ground-dwelling, now much-declined, Annamite-centred species such as Saola Pseudoryx nghetinhensis, Large-antlered Muntjac Muntiacus vuquangensis and Edwards’s Pheasant Lophura edwardsii were, by today’s standards, still common in accessible Viet Namese forests. Camera-trapping in the late 1990s in Pu Mat Nature Reserve and in Huong Son district (SFNC 2000, Timmins and Trinh 2001) suggested that the species was still relatively common in mid-elevation forests where hunting pressure was already relatively intense. The number of animals in trade in the 1990s (e.g., at Ban Lak-20 (= Ban Lak Xao) in Lao PDR; received by the Owston’s Civet Project at Cuc Phuong National Park, Viet Nam; and observed in trade near Phong Nha-Ke Bang National Park and as stuffed specimens along route 1, both Viet Nam) all suggest the species was frequent thereabouts, presumably in the mid-elevation forest where the bulk of snaring was then taking place. There is no pointer, when the difficulties of detecting this species by typical pre-camera-trap surveys are accounted for, to suggest that Owston’s Civet was not a common species throughout mid-elevation Vietnamese wet evergreen forest (see 'Habitats and ecology' section), prior to the advent of intensive snaring.

Within its range, it evidently reached, and locally still reaches, high densities within favoured habitat. Bourret (1944) considered it to be the most common civet between the Fansipan mountains and the Black river in northern Viet Nam. Two camera-trapping surveys in Viet Nam around the turn of the century, one in the Hoang Lien mountains in the north-west of the country and the other in Pu Mat Nature Reserve in the northern Annamites found this civet to be among the most commonly photographed small carnivores in these areas (SFNC 2000, S. Swan pers. comm. 2004). Pu Mat NR has not been resurveyed, but this assessment is still appropriate for the highland areas of Mu Cang Chai and Muong La, both in/near the Hoan Lien mountains, in 2013 camera-trapping (B.M. Rawson pers. comm. 2014). The same was found in 2012-2013 in Xe Sap National Protected Area, Lao PDR (Gray et al. 2014b) and during the preceding decade in parts of eastern Nakai-Nam Theun NPA (Coudrat et al. 2014). In some other areas that it has been found, it has been among the least recorded species by camera-trap, e.g. Quang Nam province, Viet Nam (Long and Minh 2006), western Nakai-Nam Theun NPA (Coudrat et al. 2014), and Nam Et-Phou Louey NPA in the northern highlands of Lao PDR (Johnson et al. 2009). The patterns of the other hunting-sensitive species recorded by these surveys suggest that Owston's Civet abundance is highly heterogeneous dependent upon habitat, not that the low encounter rates in these areas are solely a result of overhunting (although this might be responsible in part or whole for the low encounter rate in Quang Nam).

However, hunting is likely to be the explanation for the stark temporal pattern shown by the review of camera-trapping in Viet Nam by Willcox et al. (2014: Table SOM3). Of the five camera-trapping surveys operating in Viet Nam during 1998–2006, all found Owston’s  Civet; the four in 2006–2013 all did not. (Two additional sites surveyed in the latter period, Cat Tien NP and U Minh, also did not find Owston’s Civet but are excluded from the comparison as being outside the species's likely range.) Very recent (late 2013) camera-trapping in Ngoc Linh Nature Reserve (Kon Tum province, Viet Nam) and two northern highland sites, Mu Cang Chai and Muong La, found Owston's Civet to be one of most commonly photographed small carnivores (Nguyen T. pers. comm. 2014, B.M. Rawson pers. comm. 2014). These anomalies within the 2006-2013 time period, not available in time for the Willcox et al. (2014) review, are both in very mountainous areas consequently less economically appealing to market hunters. Higher hunting pressures, notably snaring intensities, typify most of the survey areas included in Willcox et al. (2014: Table SOM3). Excepting the results from Ngoc Linh NR, Mu Cang Chai and Muong La, the lack of Viet Namese records from 2006 onwards suggests a major recent decline in the species in sites across the country with large populations left only in forested steep highland massifs. This suspected decline is corroborated by the failure of over 15,000 camera-trap-nights of effort in wet evergreen forest (see 'Habitats and ecology' section) in the Hue and Quang Nam Saola Reserves, Viet Nam, since August 2012 to find the species (WWF pers. comm. to Gray et al. 2014b). Nor has it been found in another lowland area of wet evergreen forest, Khe Nuoc Truong in Quang Binh province, where extensive camera-trapping recorded many other small carnivore species (Le Trong Trai pers. comm. 2014). For none of these 2006-2013 Viet Nam camera-trap survey areas is there evidence of a pre-intensive-snaring large population of Owston' Civet. However, assessing them based on habitat and other Annamite wet evergreen forest species' status (see 'Habitats and ecology' section; R.J. Timmins [pers. comm. 2014] has surveyed in most of them and studied all on aerial imagery), Khe Nuoc Truong, Hoang Son, and non-limestone forests in the Phong Nha-Ke Bang area, are probably prime Owston’s Civet habitat; Hue and Quang Nam Saola Nature Reserves are very similar to Pu Mat NR; and Ke Go is hard to know, because few other sites are topographically similar, and the topography influences local climate. Even Crested Argus Rheinardia ocellata (among the least hunting-sensitive ground-dwelling wet evergreen forest species) has not been camera-trapped in the Hue and Quang Nam Saola Reserves; they are some of the most heavily hunted large forest blocks that R.J. Timmins (pers. comm. 2014) has ever been to.

A decline of such magnitude was not suspected during the last Red List assessment for this species, for 2008. At that stage, all camera-trap surveys within its range typically found the species, sometimes commonly. The high encounter rates in some areas suggests a high starting population and thus a long time until near extirpation (and the concomitant ability of generalised camera-trapping to note a paucity of records). Another factor weighed for the 2008 listing as Vulnerable was that one of the surveys camera-trapping the species commonly, in Hoang Lien Son of far northern Viet Nam, was amid highly degraded and fragmented forest which had been subjected to high levels of traditional hunting for decades (see Swan and O'Reilly 2004) and thus the species was resilient to hunting pressure. However, it now seems more likely that Owston's Civet differs in sensitivity to different styles of hunting (see 'Threats'). The current overall population trend is thus assessed to be steeply downwards. Probably, the main phase of decline in Viet Nam has already occurred, with most areas holding the species there now having only low numbers with large populations persisting only in the northern highlands and most rugged part of the Annamites, Lao PDR, retaining much larger areas of forest without road incursion and a much lower human population, still retains at least one large population, plausibly several (Gray et al. 2014b), but the national trend in 2015-2030 is likely to replicate that of Viet Nam in 1999-2014.

No information on the present population status in the Chinese part of the range was traced. Indeed, it is not clear that the species is still extant there.