| Citation |
Duckworth, J.W., Timmins, R., Chutipong, W., Gray, T.N.E., Long, B., Helgen, K., Rahman, H., Choudhury, A. & Willcox, D.H.A. 2016. Arctonyx collaris. The IUCN Red List of Threatened Species 2016: e.T70205537A45209459. http://dx.doi.org/10.2305/IUCN.UK.2016-1.RLTS.T70205537A45209459.en. Downloaded on 13 August 2019. |
Description |
RANGE DESCRIPTION
Greater Hog Badger occurs from Bangladesh and North-east India east through Myanmar, Thailand and Lao PDR to Vietnam and south to Cambodia and peninsula Thailand; it probably also inhabits Yunnan province, China. Inconclusive reports from the state of Perak, northernmost peninsular Malaysia, have never been confirmed (Helgen et al. 2008).
The range in Bangladesh and North-east India is provisional. Because Helgen et al. (2008) traced only a few hog badger records from this area that could be assigned to species, both mainland hog badger species might occur in this area: so the many recent records simply identified as hog badger should not, at this stage, be identified to species on any presumption of range or habitat. In North-east India the genus is well distributed all over, with most records taken to be this species including animals observed in Manas NP, north(west) of the Brahmaputra (Choudhury 2013). This contests the proposal of Helgen et al. (2008) that said drainage forms the speciess (north)west range boundary.
In Bangladesh, the genus occurs widely, with records from the South-east (Chittagong and Coxs Bazar district and Chittagong Hill Tracts), Dudhpukuria-Dhopacharia Wildlife Sanctuary (Feeroz et al. 2012), Chunoti Wildlife Sanctuary, Fasiakhali Wildlife Sanctuary, Chittagong University campus (outside the city and middle of hills), and from the North-east (Sylhet division; Moulovibazar and Habigonj districts), adjacent to Lawachara National Park (all records per Hasan Rahman pers. comm. 2014). These records are likely all to relate to this species, although objective confirmation is desirable.
Almost all hog badger specimens examined by Helgen et al. (2008) from China were judged to be A. albogularis, but two specimens from Lichiang, Yunnan, were "provisionally" assigned to Greater Hog Badger.
Than Zaw et al. (2008) traced recent hog badger records (all assumed here to be Greater Hog Badger; however A. albogularis might yet be found to occur in the far north) widely across north and central Myanmar south to about 20°N, and historical records south to about 16°30?N; survey effort was insufficient for the lack of modern records in the southern known range to be taken to suggest recent extirpation.
Surveys in 21 areas spread across Thailand found hog badger (all assumed here to be Greater Hog Badger) to be the third most widely camera-trapped small carnivore. The southernmost recent records in the country are from Tai Rom Yen National Park (8°40?N). There are historical records from further south in Thailand, but recent camera-trap survey effort south of Tai Rom Yen NP was rather limited except for in one area right on the Malaysia border (Chutipong et al. 2014).
Records in Lao PDR (all assumed here to be Greater Hog Badger) come from a wide spread of localities in the North, Centre and South. Occurrence seems to be patchy, with no recent records from the Mekong plain, which covers most of the western part of the southern half of the country (e.g., Duckworth 1997, Duckworth et al. 1999, Johnson et al. 2009, Coudrat et al. 2014, Gray et al. 2014b).
Roberton (2007) traced confirmed field records for the genus, all assumed to be Greater Hog Badger, from most of Viet Nam, occurrence was patchy and no records were found for the Mekong Delta. The current distribution in Viet Nam is likely to be highly fragmented. A recent review of small carnivore camera-trap records failed to produce any records additional to those in Roberton (2007), despite several surveys within suitable habitat, and within some of the countrys largest protected areas (Willcox et al. 2014: Table SOM3). As of mid 2014, only two camera-trap records were known for the entire country (D.H.A. Willcox pers. comm. 2014), from Pu Mat Nature Reserve (SFNC 2000) and Pu Luong NR (Do Ngoc Cuong 2004). The species has subsequently been camera-trapped in Ngoc Linh Nature Reserve, Kon Tum province (Nguyen T. pers. comm. 2014).
Although there were few historical Cambodian records, camera-trapping has recently found it at various sites spread almost throughout the country (e.g. Holden and Neang 2009, Royan 2010, Gray et al. 2014a), including Preah Vihear Protected Forest and Seima Protected Forest (WCS Cambodia unpublished data per D.H.A. Willcox pers. comm. 2014).
It has been recorded from sea-level to at least 2,300 m (see Habitat and ecology section).
DESCRIPTION
Greater Hog Badger populations have not been studied in sufficient detail for densities or trends to be known in any part of the range. Camera-trap encounter rates vary widely across its range: in some it is among the most commonly and widely photographed small carnivores, such as in Thailand (Chutipong et al. 2014) and Nakai–Nam Theun National Protected Area, Lao PDR (Coudrat et al. 2014), in others it is only rarely found if at all (e.g., modern Viet Nam: Willcox et al. 2014: Table SOM3).
At least two factors might produce this heterogeneous recording pattern: (i) natural variation in densities and (ii) human-induced declines proceeding at different rates across the range. Both are probably important. Past information is rarely precise enough to assess even the coarse population trend directly. However, judging by patterns in better documented hunting-sensitive groups of ground-dwelling mammals (e.g., wild cattle Bos, Leopard Panthera pardus, Sambar Rusa unicolor), it would be reasonable to expect human pressure to have depressed densities in Lao PDR and Viet Nam more than in Thailand and Cambodia. And this indeed seems to have happened. Recent camera-trapping has recorded the species in only very few areas in Viet Nam (Willcox et al. 2014: Table SOM3, Nguyen T. pers. comm. 2014); Roberton (2007) had already drawn attention to the surprising paucity of records in the country in the 1990s and early 2000s. In Lao PDR, by contrast, all published large-scale camera-trap surveys have found the species (Nam Et–Phou Louey NPA, Johnson et al. 2009; Nakai–Nam Theun NPA, Coudrat et al. 2014; Xe Sap NPA, Gray et al. 2014b), indicating a healthier status than in Vietnam (as is typical for hunting-sensitive species). The three camera-trap survey areas are likely to hold amongst the least-depleted large mammal faunas in Lao PDR. All are in rugged mountainous areas and indeed all post-1990 Lao records of Hog Badger come from hill and montane areas; there has been none from the plains. This pattern, making due allowance for the distribution of survey effort, was already apparent in the pre-camera-trapping era by 1999, based on direct sightings and records of dead animals or their parts (Duckworth et al. 1999). By contrast, this species is commonly recorded at low altitudes, including in plains landscapes, of Thailand and Cambodia (Royan 2010, Gray et al. 2014a, Chutipong et al. 2014) and it is common in similar lowland terrain in Kaziranga NP, Assam (Choudhury 2013). This suggests strongly that the absence of recent Lao records from such terrain (where hunting is more efficient than in rugged terrain, meaning that hunting-sensitive species across a range of vertebrate taxa tend to have declined faster there) reflects steep declines (and plausibly widespread extirpation) there.
The occurrence in Myanmar is also patchy without obvious natural explanation (Than Zaw et al. 2008); thus far, the pattern of records has not been compared closely with those of species known to be sensitive to hunting. In Cambodia, while it has been recorded relatively commonly in some areas such as parts of the north-east (Gray et al. 2014a), in the northern plains, west of the Mekong, it was not recorded in 6,000 camera-trap nights of survey in the 2012-2013 and 2013–2014 dry seasons, and the most recent record there seems to have been in 2001 (D. H. A. Willcox pers. comm. 2014). Thus area abuts Lao PDR and this apparent range retreat corroborates the suggestion that it has been hunted out from such habitat in Lao PDR. In Thailand, it seems to remain generally common with no large landscapes of (semi-) natural habitat lacking records (when patterns in survey effort are allowed for) (Chutipong et al. 2014). In North-east India the genus, although widespread, is generally not common (Choudhury 2013). The population status in its Chinese range (part of Yunnan province) seems poorly known, even at the level of genus.
HABITAT AND ECOLOGY
Greater Hog Badger is active throughout the day and night (despite past statements that the genus is nocturnal), ground-dwelling, and not very wary of people (e.g., Pocock 1941, Duckworth et al. 1999, Helgen et al. 2008, Than Zaw et al. 2008, Johnson et al. 2009, Holden and Neang 2009, Coudrat et al. 2014, Gray et al. 2014b).
Greater Hog Badger occurs down to the extreme lowlands (e.g. Bottom-Soaker National Park, Cambodia, and Kaziranga NP, Assam, India; Royan 2010, Choudhury 2013) up into the montane zone. The genus has been found up to 3,500 m, but Helgen et al. (2008) traced no record of this species above the relatively modest altitude of 1,500 m. Similarly, and based largely on different sets of records, the highest-altitude records traced for various countries are, Vietnam, 950 m (Roberton 2007); Cambodia, 1,200 m (Holden and Neang 2009); Myanmar, 1,500 m (Than Zaw et al. 2008); and Thailand, 1,016 m (Chutipong et al. 2014) . However, as cautioned by Than Zaw et al. (2008), relevant survey effort above 1,500 m has been relatively limited in Myanmar and this is generally true throughout this speciess range. Thus, the typical upper altitudinal limit may be found to be somewhat, even considerably, higher, as supported by records in Lao PDR up to nearly 2,300 m (Johnson et al. 2009). Choudhury (2013) recorded the genus up to 2,000 m in India, but suggested that the higher-altitude records would be of A. albogularis.
This species occurs across a wide variety of habitats, from heavy forest (both deciduous and evergreen) to the non-forested countryside in at least North-east India; this includes grassland-dominated floodplains such as Kaziranga NP in Assam (Choudhury 2013), where it is one of the most frequently camera-trapped small carnivores (D. Mudappa pers. comm. 2014). There are also records in Bangladesh (assumed to be this species) from tea-gardens and other non-forest habitats (Hasan Rahman pers. comm. 2014). In South-east Asia most records come from forests. The extent of actual and potential occupation of non-forest habitats is unknown: concerted survey in them is rare and off-take of mammals of this size is heavy in much of this speciess range. Thus, it is possible that they would occur widely in non-forest parts of South-east Asia but are currently excluded by hunting levels.
The diet is poorly known, but Helgen et al. (2008) speculated that it might be partly to strongly vermivorous. This was based on morphological attributes more than on direct dietary information. A strong dependence on worms would neatly explain the pattern of current habitat use in Lao PDR (see population) - widespread and still locally common in montane areas but nearly or effectively extirpated from the plains. The countrys plains have a harsh dry season, when the ground even within semi-evergreen forest (true evergreen forest is highly localised in the countrys lowlands) bakes hard. Finding large numbers of worms under such conditions is presumably difficult and highly demanding of energy. By contrast, in the mountains, forest soil remains damper through the dry season, as a result of cooler temperatures, the sometimes frequent mists and cloud, and the fuller shading of true evergreen forest. Thus, in regions with a harsh dry season, it is reasonable to suppose higher population densities in hills and mountains than in plains and low hills, and a higher resilience to hunting. Such seasonality occurs almost across the speciess range excepting most of Vietnam, the Thai-Malay peninsula and locally around massifs large enough to generate their own precipitation. Nonetheless, the species does occur in plains regions of Cambodia and Thailand with dry seasons as or more harsh than in Lao PDR; these areas have somewhat to much lower hunting pressure.
THREATS
The heterogeneous pattern of Greater Hog Badger detections and the variation in encounter rates, with the lowest rates in the very heavily hunted countries of Viet Nam and Lao PDR, strongly suggest that the species is in hunting-driven decline. Based on Lao PDR, extirpation, or decline to densities making detections extremely unlikely, seems to have proceeded faster in areas with marked dry seasons than in mountain evergreen forests with a more benign dry season, presumably because starting populations were higher in the latter habitats than in the former (see Habitats and ecology). In Viet Nam, trade-driven hunting rose to industrial levels a decade or so earlier than in Lao PDR. The low number of camera-trap survey areas in Viet Nam with records of the species indicate that even in the presumed optimal habitats of evergreen forest with only a mild dry season, steep declines and, presumably, extirpation can occur. To date, hunting is at much lower levels in the rest of this speciess range. In Lao PDR and Vietnam, much hunting involves metal cable snares set in long lines linked by drift fences, an approach very effective in catching ground-dwelling animals (e.g., Coudrat et al. 2014, Willcox et al. 2014); these snares are, mostly, big enough to secure Greater Hog Badger, because large ungulates are amongst the main targets. The geographical use of such snaring has expanded rapidly over the last 20 years and evidently continues to do so. In much of the speciess range, most people entering forest and other natural habitat for whatever reason are accompanied by dogs, many have firearms, and most secure opportunistically any animal of hog badger size-class that they come across. Being partly diurnal, ground-dwelling and not prone to shyness, hog badgers must be particularly at risk to such opportunistic off-take.
The threat which habitat change poses directly to this species is not clear. Indirectly, anything that opens up access to areas previously difficult to enter, in particular which allows vehicular removal of wildlife for sale, exacerbates the hunting threat. Almost all forms of habitat change by people co-occur with increased human access and presence, making the indirect threat from habitat change severe. Based on localities of specific records, it is unlikely that degraded and fragmented natural habitat are inherently unsuitable. These are not widely occupied probably because their higher densities of people, with concomitantly increased likelihood for badgers of lethal incidental encounters with people, prevent this. Outright conversion to entirely artificial habitat (agriculture, settlement and infrastructure) seems more likely to render an area unsuitable for Greater Hog Badger, but even this remains to be proven. Overall, the existence of large tracts of forest in the eastern parts of the speciess range with at best low densities of this species indicate that there the chief threat is hunting. While perhaps this is not yet so in parts of the western range, it is increasingly likely to become so there, too.
In Kaziranga National Park, India, numbers die in the periodic inundation of this flood-plain (Choudhury 2013). While formerly such animals might have been able to move safely to higher ground, the increasing fragmentation of natural habitat probably leads to higher mortalities nowadays. Nonetheless, in total these are likely to be insignificant to overall decline rates of the species, and are only a potential threat at the most local of levels.
Hog badger hairs are used in European shaving brush manufacture (Domingo-Roura et al. 2006) but whether this species and wild populations are involved is unclear; the large farmed stock in China (Lau et al. 2010) seems a more likely origin.
USE AND TRADE
To varying extents across its range, Greater Hog Badger is eaten, sometimes with a medicinal purpose, e.g. in the northern plains (Ai Suzuki pers. comm. 2014) and the ‘eastern plains’ of Cambodia (Gray et al. 2014a). In Lao PDR, the palatability of this hog badger varies between ethnic groups, with some groups disliking the taste, whereas groups in parts of the Nam Theun basin (and presumably elsewhere) esteem the species as food (J.P. Baker pers. comm. to Duckworth et al. 1999, J. Chamberlain per. comm. to Duckworth et al. 1999). The genus, presumably including this species, is also eaten by some groups in India (A.U. Choudhury pers. comm. 2006), and is hunted as well as farmed for food in China (M.W.N. Lao pers. comm. 2006). Across most of its range, most of the catch is probably not targeted, but is by non-selective methods for wildlife meat, or opportunistically during activities other than hunting.
CONSERVATION ACTIONS
Throughout its range, Greater Hog Badger is found in a number of protected areas, perhaps particularly in Myanmar, India and Thailand (Than Zaw et al. 2008, Choudhury 2013, Chutipong et al. 2014). This species is protected by law in Thailand (Chutipong et al. 2014), in Bangladesh (as a Schedule 1 species) under the Wildlife Act 2012 (Hasan Rahman pers. comm. 2014), and in India, under the highest level of protection (Choudhury 2013). This species is not protected in Viet Nam or Cambodia and is the largest-bodied unprotected mammal, except for Eurasian Wild Hog Sus scrofa, in Myanmar (Than Zaw et al. 2008). The China Red List has listed hog badgers (as a monospecific genus, under this speciess name) as Vulnerable under C1 and A2c. |
