| Citation |
Kamler, J.F., Songsasen, N., Jenks, K., Srivathsa, A., Sheng, L. & Kunkel, K. 2015. Cuon alpinus. The IUCN Red List of Threatened Species 2015: e.T5953A72477893. http://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T5953A72477893.en. Downloaded on 08 August 2019. |
Description |
RANGE DESCRIPTION
Historically, Dholes occurred throughout South and East Asia, to as far north as the southern parts of the Russian Federation (including the Amur region and upper Lena River north of Lake Baikal), and as far west as the mountains ranging from eastern Kazakhstan to northern Pakistan (Altai, Tian Shan, Pamir and western Himalayan mountains; Heptner and Naumov 1967). Dholes have disappeared from >75% of their historic range, and most remaining populations are fragmented and still appear to be declining based on scattered surveys and personal observations. Their current distribution, based on recent information we consider reliable, is described below.
Central and East Asia: there have been no confirmed reports of Dholes in more than 30 years from the Russian Federation, Mongolia, Kazakhstan (formerly in the Altai and Tian Shan mountains), Kyrgyzstan (formerly in the Tian Shan and Pamir mountains), Afghanistan (formerly in Pamir Mountains), Tajikistan (formerly in Pamir Mountains) or Uzbekistan (formerly in Tian Shan Mountains), and they are likely extirpated from these regions (A. Poyarkov and N. Ovsyanikov in litt., D. Miquelle pers. comm.).
Bangladesh: Dholes still occur in some forest reserves in the Sylhet area in northeastern Bangladesh, as well the Chittagong Hill Tracts in southeastern region. However, these areas are unlikely to contain viable populations because Dholes are usually sighted only as solitary individuals, or in small groups of two to three adults. Dhole numbers appear to be decreasing in these areas due to a decreasing prey base (S. Chakma pers. comm.).
Bhutan: Although Dholes were nearly extirpated in Bhutan in the 1970s and early 1980s due to poisoning campaigns, this species began to re-occupy the country starting in the 1990s (Wangchuk 2004, Thinley et al. 2011). Based on sign and interviews with park managers, they now occur in most, if not all, protected areas in the country (J. Kamler unpubl. data).
Cambodia: There are recent (under five years old) records of Dholes in the Cardamom Mountains (FFI-Cambodia Programme unpubl. data), the northern plains landscape (WCS Cambodia Program unpubl. data), the eastern plains landscape (J. Kamler unpubl. data), and northeastern Cambodia (Siem Pang Province; D. Willcox unpubl. data). Dholes do not likely exist in viable populations outside of these areas. A recent outbreak of canine distemper in 2011-2012, thought to have originated in local domestic dogs, caused the near-extirpation of Dholes in both the eastern and northern plains landscapes (J. Kamler and A. Suzuki unpubl. data), but it appears these populations are slowly recovering as of 2015.
China: Historically Dholes occurred throughout China, but their current status and distribution is highly uncertain, and they are likely extirpated throughout most of the country. Despite extensive surveys throughout the country, recent (<10 years) records from China come only from six provinces: Gansu, Sichuan, Shaanxi, Yunnan, Tibet Autonomous Region (TAR) and Xinjiang. In northern Gansu Province, Dholes were recently reported from the Qilian Shan Mountains as a pack was observed there in 2003 (Harris 2006) and a mother with pups was photographed in Yanchiwan Nature Reserve in 2013 (Riordan et al. 2015). As the Qilian Shan Mountains extend into northern Qinghai Province, Dholes still might occur there as well. In southeastern Xinjiang Province, camera traps recorded Dholes during 2012-2013 in the Altun (Altyn-Tagh) Mountains (Xue et al. 2014). In western Xinjiang Province, there were sightings by local people during 2011-2013 in Taxkorgan Nature Reserve (Riordan et al. 2015). In central Sichuan, a Dhole was photographed in 2012 in Heishuihe Nature Reserve in the Qionglai Mountains (Y. Zhou pers. comm.). Although one Dhole was observed in 2003 in Tangjiahe Nature Reserve in northern Sichuan (Y. Zhou pers. comm.), there have been no camera trap photos or other confirmed records in the past 10 years (S. Li pers. comm.). Dholes may occur in the Minshan Mountains (northern Sichua) and Daxue Shan Mountains (western Sichuan), as there are former records from there and current prey densities are relatively high (S. Li pers. comm., Li et al. 2010). In Shaanxi Province, a Dhole was recently recorded during a camera trap study in Guanyinshan Nature Reserve in the Qinling Mountains (Liu et al. 2013). However, camera trap studies in several other nature reserves in Shaanxi failed to record Dholes (S. Li pers. comm.), so their numbers must be extremely low in the area. In Yunnan Province, Dholes were photographed in camera traps in both the Nangunhe and Xishuangbanna nature reserves in 2012-13 near the border with Myanmar (Wildlife Institute, Beijing Forestry University, unpubl.), but Dhole numbers are likely low there due to highly fragmented habitat, high poaching, and extremely low prey densities (S. Li pers. comm.). In TAR, camera traps recorded Dholes in 2014 in Motuo (Mêdog) County (southeastern TAR; S. Li pers. comm.). Although there are few recent records, Dholes may still occur in the southern parts of TAR, as this species was recorded in the Mt. Qomolangma (Mt. Everest) Nature Reserve (Hu et al. 2014). In southeastern China, the last two records of Dholes come from Jiangxi Province: the unconfirmed report of one captured in early 2000s (C. Bellamy pers. comm.), and an unconfirmed photo taken by a camera trap in Taohongling Nature Reserve in 2010 (S. Li pers. comm.). However, there have been no confirmed reports or additional records from other areas, and they are now likely extirpated from the region. Interviews with local people suggested that Dholes disappeared from large areas of central and southern China during the 1980s and early 1990s, after locals starting poisoning carcasses in retaliation for livestock losses from Dholes (S. Li pers. comm.).
India: Dholes occur in several regions of India, and this country undoubtedly contains the largest numbers of Dholes. That said, Dholes have disappeared from 60% of their historic range in India during the past 100 years (Karanth et al. 2010). Relatively high populations of Dholes are still found in the Western Ghats and central Indian forests, due to high prey numbers and extent of protected forests, whereas lower numbers of Dholes are found in the Eastern Ghats (Karanth et al. 2009). Dholes are also found in the northeastern states, although numbers are low and decreasing in this region due to a decreasing prey base and retaliatory killings from livestock predation (Gopi et al. 2012, Lyngdoh et al. 2014). Dholes are found in some areas of Terai region in northern India (Karanth et al. 2009), although their exact distribution there is unknown. In the Himalayan region, Dholes were recently reported from Sikkim (Bashir et al. 2014), and in 2008 near Tso Kar in Ladakh (R. Simpson pers. comm.), thus they may occur in other areas of Ladakh as well.
Indonesia (Sumatra and Java): Historically, Dholes occurred throughout both Sumatra and Java; however, their current distribution on both islands is fragmented and greatly reduced. On Sumatra, Dholes have recently been confirmed in several national parks along the Barisan Mountain range, ranging from the northern to southern parts of the island (e.g., Gunung Leuser, Kerinci Seblat and Bukit Barisan Selatan National Parks; FFI, WCS and WWF country programs unpubl. data). Dholes also have been recently confirmed in several protected areas in lowland forests in the east-central part of the island (e.g., Tesso Nilo and Bukit Tigapuluh National Parks, Harapan Rainforest and Batang Hari Protection Forest; FFI and WWF country programs unpubl. data). On Java, Dholes have recently been confirmed in national parks only in the extreme western (e.g., Gunung Gede Pangrango, Ujung Kulon and Gunung Halimum Salak National Parks) and eastern (e.g., Baluran National Park and Alas Purwo National Park) parts of the island (A. Ario pers. comm.). They are likely extirpated in other regions of the island.
Korean peninsula: Historically, Dholes occurred on the Korean peninsula, but were likely extirpated throughout most of their range by the 1970s (Won and Smith 1999). In the 1980s Dholes were confirmed to still occur on Mt. Pakdoo in northeastern Korea DPR, near the Chinese border (Won and Smith 1999). However, there have been no available data since that time, so their status in Korea DPR remains uncertain. They are certainly extirpated from the Republic of Korea.
Lao PDR: There are recent (under five years old) records of Dholes from northern Lao PDR (Nam Et-Phou Louey [NEPL] and Nam Ha protected areas) and in central Lao PDR (Nakai-Nam Theun and Nam Kading protected areas; WCS-Lao PDR program unpubl. data, C. Coudrat pers. comm.). The most studied and perhaps largest population of Dholes in the country is in NEPL (Kamler et al. 2012). There are no recent records of Dholes in southern Lao PDR, and they are probably extirpated from this region.
Malaysia (peninsula): The historical range of Dholes likely included the entire Malaysian peninsula, possibly even what is now Singapore. Dholes are now extirpated from Singapore and the southern forests of the Malaysian peninsula (Endau-Rompin complex; WCS Malaysia Program, unpubl.). Based on recent camera trapping surveys, Dholes still occur in the central (Taman Negara) and northern (Belum-Temengor complex) forested areas of the Malaysian peninsula (K. Kawanishi pers. comm.).
Myanmar: The current distribution of Dholes in Myanmar is uncertain. In the late 1990s and early 2000s, they were recorded by camera traps at 11 of 15 survey areas scattered across the country (Durbin et al. 2004). However, numbers and distribution may have decreased since that time. For example, Dholes had been recorded in Chatthin Wildlife Sanctuary in western Myanmar, where they reportedly predated on livestock. Apparently, local people persecuted Dholes in retribution, and consequently Dholes were not detected in Chatthin during recent camera-trapping surveys (N. M. Shwe unpubl. data). Since 2005, Dholes have been recorded from several protected areas in Myanmar, including the northern region (Hukaung Valley Wildlife Sanctcuary and Htamanthi Wildlife Sanctuary), west-central region (Mahamyaing Wildlife Sanctuary and Namataung National Park), southwestern region (Rakhine Yoma Elephant Range), and peninsula region (Tanintharyi Nature Reserve; WCS Myanmar Program unpubl. data). From 1999-2002, Dholes were recorded in at least eight additional forest tracts and protected areas the in northern, western, and central parts of the country (WCS Myanmar Program unpubl. data), thus Dholes may still occur throughout these regions. There are few confirmed records of Dholes from eastern Myanmar, although they likely occur near the tri-border area with Lao PDR and Thailand, as there are records in that area from those countries. There are recent records of dholes from camera-trap studies in Karen (Kayin) State (R. McEwing pers. comm.), but their status in other areas of eastern Myanmar is not known.
Nepal: Dhole sightings in Nepal are not common, yet there are recent reports of this species in several areas of country. In the Himalayan region, Dholes reportedly occur in the western (Rara and Khaptad National Parks, Dhorpatan Hunting Reserve; R. D. Choudhary pers. comm., A. Aryal in litt.) and extreme eastern parts (Kanchenjunga Conservation Area; Khatiwada 2011) of the country. In southern Nepal, Dholes are found throughout much of the Terai Arc Landscape, including Chitwan and Bardia national parks (Thapa et al. 2013, A. Khatiwada pers. comm.), and Parsa and Shuklaphanta Wildlife Reserves (A. Khatiwada pers. comm.). Dholes also are reported in several districts of Nepal outside protected areas, but all populations are extremely low and threatened by low prey base, poisoning and habitat loss (A. Khatiwada pers. comm.).
Pakistan: Although there are no confirmed records of Dholes from Pakistan, they historically occurred in the western Himalayan Mountains in the northern part of the country. They might still occur in the Ladakh region of northern Parkistan, as Dholes recently have been recorded in the India-administered region of Ladakh.
Thailand: Dholes have been extirpated from most areas of Thailand, and are now absent from the peninsula and eastern parts of the country. Dholes are still found in fragmented populations in several large protected-area complexes, including the south-central region (Phayayen-Khao Yai and Eastern Forest complexes), north-central region (Phumieng-Phuthong and Phukhieo-Namnow complexes), northwestern region (Srilanna-Khutan and Doi Phucar-Maeyom complexes), and western region (Western Forest Complex; Jenks et al. 2012; Department of National Park, Wildlife and Plant Conservation, Thailand). It is not yet known how stable are these isolated populations, and if the protected-area complexes are large enough to conserve viable Dhole populations in the long term.
Viet Nam: There are very few recent confirmed records on Dholes in Viet Nam. The last confirmed records of Dholes were in Pu Mat National Park in 1998-99 (D. Willcox pers. comm.) and in Yok Don National Park in 2003 (J. Eames pers. comm.) despite extensive camera trapping in >25 protected areas throughout the country. Along with other large carnivores, Dholes are likely extirpated from Viet Nam, although individuals may occasionally enter the country from neighboring Cambodia or Lao PDR
DESCRIPTION
Background
Because so little is known about Dhole ecology, we used African Wild Dogs (Lycaon pictus) as a surrogate species for estimating the proportion of mature individuals and generation length. Of the canids, African Wild Dogs are arguably most similar to Dholes. Both species have specialized dental morphology for obligate hypercarnivory (Van Valkenburgh 1991), which is rather unique among canids. Phylogenetic research shows both species are in the same monophyletic group (Lindblad-Toh et al. 2005), and otherwise both species are similar in body size, reproduction, social behaviour and feeding behaviour (Johnsingh 1982). Consequently, much of the text below comes directly from the IUCN assessment for the African Wild Dog (Woodroffe and Sillero-Zubiri 2012).
Proportion of mature individuals
Estimating the number of “mature individuals” is challenging for Dholes, because like African Wild Dogs, they are obligate cooperative breeders (Johnsingh 1982, Venkataraman 1998). Consequently, within a pack the alpha male and female are the parents of the majority of surviving pups (Venkataraman 1998). Although the IUCN Red List Categories and Criteria (IUCN 2012) define mature individuals as “individuals known, estimated or inferred to be capable of reproduction”, it does not specify the time period within which reproduction is considered possible. The User Guidelines (IUCN 2014) go on to state “in many taxa there is a pool of non-reproductive (e.g., suppressed) individuals that will quickly become reproductive if a mature individual dies. These individuals can be considered to be capable of reproduction”. As with African Wild Dogs, a high proportion of individual Dholes within a park are indeed reproductively suppressed (Johnsingh 1982, Venkataraman 1998), but these animals do not necessarily become reproductive “quickly” if an alpha individual dies. In a mature pack, most pack members are offspring of the alpha pair; for these animals, death of an alpha would usually not open up a breeding opportunity because no unrelated mates would be available within the pack. Given these complexities, and in keeping with the spirit of capturing a “snapshot” of current conditions, we have chosen to define mature individuals as those considered capable of reproduction within the current breeding season. The number of mature individuals thus comprises the number of alpha males and females, and the number of sub-dominant (i.e. non-alpha) animals that breed successfully.
Following that reported for Africa Wild Dogs (Woodroffe and Sillero-Zubiri 2012), we estimated for Dholes the number of mature individuals (Nm) from populations of adults and yearlings (Nc). The number of alpha males (NaM) and alpha females (NaF) would be estimated with the following equations:
NaM = Nc x 0.55 x 0.176NaF = Nc x 0.45 x 0.215
The above equations result in approximately equal estimates of the numbers of alpha males and alpha females. Also following that reported for African Wild Dogs (Woodroffe and Sillero-Zubiri 2012), we estimated for Dholes the number of sub-dominant breeders (Nsub) as:
Nsub = (NaM x 0.10) + (NaF x 0.08)
Therefore, the number of mature individuals (Nm) for Dholes could be calculated using the following equation:
Nm = NaM + NaF + Nsub
Population size and densities
Population estimates of Dholes are not available for any country. Therefore, we made an attempt to estimate the total population of Dholes by classifying countries within their current distribution as having high (1,500-3,000), medium (750-1,500), or low (250-750) numbers of Dholes. These classifications were based on estimates of relative abundances and area covered by Dholes within each country. We classified one country as having high numbers of Dholes (India), two countries with medium numbers (Thailand, Myanmar), six countries with low numbers (Bhutan, Cambodia, China, Lao PDR, Malaysia, Nepal), and four countries with negligible numbers (Bangladesh, Korea DPR, Pakistan, Viet Nam). Consequently, we estimate the total population of Dholes to be 4,500–10,500. Although there is relatively high uncertainty with this population estimate, it has a large range and we feel that it adequately represents the possible population size of Dholes.
To calculate total population of mature individuals, we used the equations above to show an estimate of 436-1,016 alpha males (NaM), 435-1016 alpha females (NaF), and 78-183 sub-dominant breeders (Nsub). This resulted in an estimate of 949-2,215 mature individuals (Nm), which is below the 2,500 threshold (i.e., one of the criteria for listing as EN under C).
The only estimates of local Dhole densities come from a few protected areas in India. Only one of those estimates has been obtained through systematic sample-based survey methods (Selvan et al. 2014), whereas the others are presumably based on estimates of the number of packs within the protected areas (derived using known home range areas and knowledge of mean pack sizes). Reported Dhole densities were 0.066 Dholes/km2 in Pakke Tiger Reserve (Selvan et al. 2014), 0.095 Dholes/km2 in Mudumalai Wildlife Sanctuary, 0.13 Dholes/km2 in Bandipur Tiger Reserve, and 0.3 Dholes/km2 in Pench National Park (Durbin et al. 2004).
The size of subpopulations of Dholes has not been reported anywhere. Therefore, the following is our estimate of the size of one of the largest subpopulations of Dholes, which is presumed to be in the Western Ghats of India, based on high prey numbers and extent of protected forests in the region. This region contains the most intensively studied subpopulation of Dholes in the world (Johnsingh 1982, Venkataraman et al. 1995, Karanth and Sunquist 1995, Venkataraman 1998, Karanth and Sunquist 2000, Andheria et al. 2007, Ramesh et al. 2012, Srivathsa et al. 2014). Srivathsa et al. (2014) estimated the proportion of area occupied by Dholes in the Malenad landscape (Western Ghats in the State of Karnataka), by assessing "true occupancy" in 206 grid-cells (188 km2 each). This area covers 16 wildlife reserves, where the highest numbers of Dholes are likely restricted to four source populations: Anshi-Dandeli, Bhadra, Nagarahole-Bandipur and Biligiri Rangaswamy Temple (BRT) reserves. Abundance was derived from estimates of occupancy, based on the Royle-Nichols (2003) occupancy model [abundance in a grid-cell= Log (1/(1-PSI))] for all the 206 grid-cells. We calculated a range of abundances for each source population, which likely represent one metapopulation. The lower limit of this range is the sum of grid-cell-wise abundances from those cells that intersect with the reserve boundaries; the upper limit of this range is the sum of grid-cell-wise abundances for the reserve+the cells that are first order neighbours for the reserve cells (with contiguous forest habitats). The following are the abundance ranges for the four source populations: Anshi-Dandeli = 15-46; Bhadra = 23-39; Nagarahole-Bandipur = 85-91, BRT = 24-28. We estimate the remaining forested landscape may support 60-100 Dholes, resulting in a total population of 207-304 individuals. To calculate total number of mature individuals in this subpopulation, we used the above equations which resulted in an estimate of 44-64 mature individuals (20-29 alpha males, 20-29 alpha females, four to six sub-dominant breeders). Clearly, even one of the largest subpopulations of Dholes contains well below 250 mature individuals (i.e., the criterion for listing as EN under C2a(i)).
Change in population size
There is almost no quantitative information on Dhole population trends through their distribution. In fact, a common characteristic of Dhole populations is that they often exhibit severe local population fluctuations (Johnsingh 1982, Venkataraman 1998, Karanth and Sunquist 2000, Durbin et al. 2004, J. Kamler pers. obs.), which makes estimating populations and population trends difficult. We estimate that the total population of Dholes is still decreasing, due to the continuous decline in their distribution.
HABITAT AND ECOLOGY
The Dhole is a habitat generalist, and can occur in a wide variety of vegetation types, including: primary, secondary and degraded forms of tropical dry and moist deciduous forests; evergreen and semi-evergreen forests; temperate deciduous forests; boreal forests; dry thorn forests; grassland–scrub–forest mosaics; temperate steppe; and alpine steppe. Consequently, their elevation range is from sea level to as high as 5,300 m asl in Ladakh (R. Simpson pers. comm.). They have not been recorded in desert regions.
The Dhole is one of only three canid species with specialized dental adaptations for an exclusively carnivorous diet, termed hypercarnivory (Van Valkenburgh 1991). Although Dholes consume a wide variety of prey species, ranging from small rodents and hares to Gaur (Bos gaurus; Karanth and Sunquist 1995, Andheria et al. 2007, Ramesh et al. 2012, Selvan et al. 2013a), the preferred prey are ungulates with a body mass of 40-60 kg (Selvan et al. 2013b). However, if this prey size is not available, Dholes will selectively prey upon both smaller and larger ungulate species (Kamler et al. 2012). Seasonal changes occur in the Dhole diets, reflecting seasonal changes in availability and numbers of prey (Thinley et al. 2011). In India, Dholes form relatively large packs (usually five to 10, but up to 25 adults) to efficiently hunt large numbers of prey, as well as to protect litters, which are usually large (usually five to 10, but up to 12 pups; Johnsingh 1982, Venkataraman et al. 1995, Durbin et al. 2004). However, in tropical evergreen forests of Southeast Asia, Dholes appear to persist in smaller packs and presumably have smaller litters, probably due the low prey biomass and small size of ungulate prey in these habitats (Kawanishi and Sunquist 2008).
Due to the demands imposed by hypercarnivory, sufficient numbers of ungulate prey are the Dhole’s major habitat requirements. In India, tropical dry and moist deciduous forest may represent optimal habitats, based on the areas thought to hold the largest Dhole populations. Ungulate biomass, particularly that of cervid species, is highest in these habitat types when compared to other habitats in the same region (A. Venkataraman and V.N. Babu unpubl.). Besides prey numbers, other important factors that may influence habitat use include levels of human disturbance, water availability, tiger presence, and suitability of breeding sites (Steinmetz et al. 2013, Srivathsa et al. 2014, J.F. Kamler unpubl. data).
Home range sizes of Dholes reportedly ranged from 23-199 km2 in India (Johnsingh 1982, Venkataraman et al. 1995, Karanth and Sunquist 2000, Acharya 2007) and from 60-80 km2 in Thailand (Grassman et al. 2005, K. Jenks unpubl. data).
THREATS
Depletion of prey base: This may be the single greatest factor that contributed to the range collapse of Dholes in the northern half of their former distribution, and might be the primary factor for the continued decline of Dholes in the southern half of their distribution. Throughout Cambodia, Lao PDR, Viet Nam, and southeastern China, ungulate populations are well below carrying capacity due to over hunting by humans, even within protected areas (Durbin et al. 2004). All ungulate species, except perhaps Muntjac (Muntiacus spp.) and Wild Pig (Sus scrofa), are ecologically or fully extinct across extensive parts of the region (Durbin et al. 2004). This situation will likely hinder any possibility of recovery by the regions Dhole populations, even if the other issues could be addressed. Dholes can probably persist as fragmented populations in large protected areas of Bhutan, Malaysia, Myanmar, Nepal, Indonesia (Sumatra and Java) and Thailand, as long as prey numbers remain sufficient and other threats are controlled. In large protected areas in southern and central India, Dhole numbers are stable where prey densities are high. In northeastern India, prey depletion is contributing to the decline of Dholes in the region (Gopi et al. 2012).
Habitat loss and transformation: Habitat loss and degradation are serious threats to Dholes in southern Asia, particularly because this threat is closely associated with prey depletion and high levels of human disturbance. Although extensive areas of natural or semi-natural vegetation remain in Lao PDR and Cambodia, habitat conversion and fragmentation are proceeding unabated. In Viet Nam, very few natural areas greater than 50 km2 remain. Habitat loss and fragmentation is a major threat to protected areas in Indonesia, particularly those on Sumatra. Habitat loss is driven by several different factors, including logging, palm and rubber plantations, agriculture expansion, rural biomass extraction, livestock grazing and major infrastructure expansion (e.g., hydropower dams, irrigation projects, new highways, etc.).
Persecution: Persecution of Dholes stems mainly from retaliatory killings due to livestock predation, and this factor is driving some Dhole populations towards local extinction (Lyngdoh et al. 2014). Dholes appear to be especially susceptible to poisoning of carcasses using strychnine or other rodenticides, which often are readily available to rural people in southern Asia. Consequently, unsystematic but consistent poisoning of carcasses can easily wipe out Dholes within an area, especially because the entire pack will feed on a carcass. For example, poisoning of livestock carcasses apparently wiped out Dholes from Bhutan in the 1970s and early 1980s, although this species began to re-occupy the country starting in the 1990s (Wangchuk 2004, Thinley et al. 2011). Killing of Dholes by poisoning livestock carcasses also has been reported in China, Nepal, India and Indonesia, and is likely is widespread in southern Asia. Poisoning campaigns also were thought to have contributed to the extirpation of Dholes in the countries of the former Soviet Union (Ginsberg and Macdonald 1990).
Dholes reportedly have been shot by humans, as Dhole carcasses with gun-shot wounds were found near the boundary of protected areas in Thailand (K. Jenks and N. Songsasen unpubl.). Dholes are probably susceptible to non-selective snaring, particularly where this activity is widespread such as in Viet Nam, Cambodia, China and Lao PDR. In India, and possibly elsewhere, Dholes living outside or on the edge of core protected areas are particularly vulnerable to human kleptoparasitism.
Disease and pathogens: Dholes are susceptible to rabies, canine distemper, canine parvovirus and sarcoptic mange among others (Durbin et al. 2004), which are usually contracted from domestic village dogs that act as reservoirs. Dholes appear to be especially susceptible to disease epizootics due their large pack sizes and high levels of amicable behaviour within packs, even among adults (Johnsingh 1982). Such behaviours likely result in relatively high intraspecific contact rates, which are conducive for disease epizootics, at least compared to other wild canids such as jackals (Canis aureus) which are more solitary. Disease epizootics may contribute to the sudden disappearance of Dholes from protected areas, and often cause severe local population fluctuations resulting in relatively small pack sizes (Karanth and Sunquist 2000, J. Kamler pers. obs.). In Cambodia, a recent outbreak of canine distemper in 2011-2012, thought to have originated in local domestic dogs, caused the near-extirpation of Dholes from protected areas in the eastern and northern parts of the country (J. Kamler unpubl.), although populations appear to be recovering; mortalities associated with canine distemper also have been observed in a protected area in Thailand (N. Songsasen and K. Jenks unpubl). The range-wide effects of diseases on Dhole population dynamics is unknown, but it is likely significant across southern Asia, and might result in an increased probability of extirpation for Dhole populations in isolated protected areas.
Competition with other species: Aside from humans, the main competitors of Dholes for limited resources are Tigers (Panthera tigris) and Leopards (P. pardus). Although Dholes are much smaller in body size, packs of Dholes reportedly have killed both Tigers and Leopards, although the reverse also has been reported (Burton 1940). The dominance hierarchy between Dholes and Tigers is not clear, although Dholes likely avoid tigers especially if packs are small. Dholes appear to be behaviourally dominant over Leopards, and packs of Dholes often tree this species when they interact (Venkataraman 1995). Whether large felids can negatively affect Dhole numbers is unknown, although the exploitive and interference competition between them likely becomes more intense as prey populations are reduced by humans, possibly resulting in spatial exclusion where prey numbers are lowest. Free-ranging dogs also may compete with Dholes for limited food resources where prey numbers are low.
USE AND TRADE
There is no widespread exploitation of Dholes for fur or other purposes, and there apparently is little if any value for their use as traditional medicines. Thus, wildlife trade does not directly affect Dholes. |
