Rusa timorensis 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Mammalia Cetartiodactyla Cervidae

Scientific Name: Rusa timorensis (de Blainville, 1822)
Common Name(s):
English Javan Deer, Javan Rusa, Rusa, Rusa Deer, Sunda Sambar, Timor Deer
French Cerf de Timor
Spanish Sambar de Java
Cervus celebensis Rorig, 1896
Cervus hippelaphus G.Q. Cuvier, 1825 [preoccupied)]
Cervus lepidus Sundevall, 1846
Cervus moluccensis Quoy & Gaimard, 1830
Cervus peronii Cuvier, 1825
Cervus russa Muller & Schlegel, 1845
Cervus tavistocki Lydekker, 1900
Cervus timorensis de Blainville, 1822
Cervus timorensis ssp. rusa Muller & Schlegel, 1845
Cervus tunjuc Horsfield, 1830 [nomen nudum]
Taxonomic Notes:

The classification of Rusas in their own genus as Rusa rather than Cervus was suggested by Van Bemmel (1949, cited by Emmerson and Tate 1993) based on the geographic distribution of these animals. While simple geographical or morphological characteristics may not be enough to justify a classification, cervine and rusine deer have different chromosome numbers (cervine: 2n = 66 to 68, rusine: 2n = 56 to 65; Neitzel 1987 and Wang et al. 1982, cited by Emmerson and Tate 1993; Gilbert et al. 2006; data in Groves and Grubb 2011) and these species do not interbreed. More recently, the division of the genus Cervus into four subgenera including Rusa, and the classification of Rusas in that subgenus was suggested by Groves and Grubb (1987) and has since been supported by extensive genetic studies (Meijard and Groves 2004).

Wilson and Mittermeier (2011) have listed seven timorensis subspecies: R. t. timorensis (Timor), R. t. djonga (Muna and Buton), R. t. floresiensis (Flores), R. t. macassaricus (Sulawesi), R. t. moluccensis (Moluccan Islands), R. t. renschi (Bali), and R. t. russa (Java). Others disagree that R. timorensis can be separated into subspecies and suggest that the apparent differences between the groups listed above are simply due to the genetic effects of small populations, and to environmental effects which have caused the development of phenotypically (but not genetically) different populations.

However, it has been accepted by several authors (e.g. Hill, Thomas and Mackenzie 1987; Dahlan 2009) that Javan (designated R. timorensis russa) and Moluccan (R. t. moluccensis) deer are different subspecies. This distinction has been based in some instances on the origin of the population under consideration, and on differences in size and pelage (Mackenzie 1985, Groves and Grubb 2011), and are therefore inconclusive. However, there are distinct differences in breeding season when the two “breeds” are managed in the same environment (Woodford 1994). That the Moluccan deer may be in the process of evolving away from the Javan “parent “ population is strongly indicated by the work of Emmerson and Tate (1993) who concluded, on the basis of phenetic and cladistic analyses, that Rusas from Java and Molucca should be divided into different subspecies, with a genetic distance (Nei 1972) of about 0.08. The validity of separating the other six subspecies suggested by Grubb (2005) has apparently not been established.

Assessment Information [top]

Red List Category & Criteria: Vulnerable C1 ver 3.1
Year Published: 2015
Date Assessed: 2014-11-17
Assessor(s): Hedges, S., Duckworth, J.W., Timmins, R., Semiadi, G. & Dryden, G.
Reviewer(s): Brook, S.M. & McShea, W.J.
Javan Deer is still locally common within its rather small native geographic range, but is assessed as Vulnerable (C1) because its total native population is estimated to number fewer than 10,000 mature individuals, with an estimated continuing decline of at least 10% within three generations (estimated as a minimum of 15 years) as a result of habitat loss, habitat degradation, and poaching. The rise in hunting reflects institutional and socio-economic factors which are not readily reversible and therefore speedy solution is unlikely. Open-country herding deer are very susceptible to inadequately managed hunting in tropical Asia. This decline is continuing, except in national parks and inaccessible areas, but increased government surveillance and lower numbers of animals has meant that loss due to hunting is decreasing. The main threat now appears to be loss of habitat (G. Dryden pers. comm. 2014).
Previously published Red List assessments:

Geographic Range [top]

Range Description:The Javan Rusa is believed to be native only to Java and Bali in Indonesia (Corbet and Hill 1992, Heinsohn 2003, Grubb 2005). It has been introduced to many other islands of the Indo-Pacific region (Corbet and Hill 1992, Heinsohn 2003, Grubb 2005, Groves and Grubb 2011). Some introductions apparently took place in antiquity within present-day Indonesia, to the Lesser Sunda islands, Maluku (= Molucca) islands (including Buru and Seram), Sulawesi, and Timor. On Timor, the species inhabits both West Timor (part of Indonesia) and Timor Leste (G. Semiadi pers. comm. 2008, based on 1998 data). Indonesian islands with introduced populations include: Alor, Ambon, Banda, Batjan, Buru, Butung, Flores, Halmahera, Komodo, Lembeh, Lombok, Mangole, Muna, Papua, Sanana, Saparua, Seram, Sulawesi, Sumba, Sumbawa, Taliabu, Ternate, Timor, and Wetar (Wiradteti pers. comm.). Like many large deer, the Javan Rusa is an able swimmer (Kitchener et al. 1990), hindering determination of its native range. The originally introduced population in Borneo is now probably extinct (Payne et al. 1985, G. Semiadi pers. comm. 2008), but in the 1990s soldiers returning from Timor brought some Javan Rusas to at least the Tanah Grgot and Penajam Paser Utara districts in East Kalimantan. Hybridization of Sambar R. unicolor (which occurs naturally in Borneo) with the introduced Javan Rusas has been confirmed from molecular and morphology in one captive herd (221 heads) belonging to the East Kalimantan Province's Animal Husbandry Office at Penajam Paser Utara district (G. Semiadi pers. comm. 2008).

Javan Rusas were introduced to New Caledonia in the 1870s (Maudet 1999), and to Mauritius and Reunion Island in 1639. According to R.J. Safford (pers. comm. 2008) Réunion received several introductions from Mauritius; the current population is derived mainly from five batches introduced in 1954. Also seven (individual) Red Deer Cervus elaphus were introduced from France; the final outcome with the latter (including any hybridization with Javan Rusas which may or may not have occurred) is unknown but nowadays 'deer' are not common on Réunion, although they are still present in a few areas, and are a pest where they occur. Rodrigues holds no Javan Rusas, although there was a failed attempt to introduce them (Cheke and Hume 2008). Introductions have been made in the 20th century to New Zealand (1907, Fraser et al. 2000), Malaysia (1993/4), and to Brazil, Madagascar and Thailand (Maudet 1999). Javan Rusas were introduced to the Port Moresby region of Papua New Guinea from Java in 1900 (Maudet 1999) and a small population has persisted there and has spread north into the Owen Stanley Range with a herd near Wewak on the north coast; introductions to islands of the Bismarck Archipelago have either not persisted or are present in small numbers (Mammals of Papua 2009-2014). The first introductions to Australia were to Victoria (1868) and New South Wales (1890) (Maudet 1999) and wild herds of Rusas have spread to Queensland and South Australia (Moriarty 2004).

Javan Rusas of Moluccan origin were introduced to West Papua in the first quarter of the 20th century; their range now includes the southern coastal plains of New Guinea from the Gulf of Papua to the Fak-Fak Peninsula, and the Doberai Peninsula and foothills of the Foja Mountains in the north (Mammals of Papua 2009-2014). An introduction was probably attempted onto Anjouan, in the Comoros, in the 19th century, but Javan Rusa is long extinct there (Louette 2004). On Madagascar, Javan Rusas were introduced near Périnet (Andasibe) around 1930, survived until at least 1955 but is now extirpated, probably having disappeared in the 1960s (Goodman and Benstead 2003: 1172-1173). The distribution map shows only native populations on Java and Bali, not introduced populations. Introduced populations are not counted as part of this assessment.

Countries occurrence:
Indonesia (Bali, Jawa, Kalimantan - Introduced, Lesser Sunda Is. - Introduced, Maluku - Introduced, Papua - Introduced, Sulawesi - Introduced)
Australia; Brazil; Malaysia; Mauritius; New Caledonia; New Zealand; Papua New Guinea; Réunion; Thailand; Timor-Leste
Additional data:
Upper elevation limit (metres):900
Range Map:Click here to open the map viewer and explore range.

Population [top]


The Javan Rusa is common in much of its current range (Kitchener et al. 1990, Corbet and Hill 1992, Whitehead 1993, Heinsohn 2003, Moriarty 2004). Most populations are outside the native range (Corbet and Hill 1992, Whitehead 1993, Heinsohn 2003, Moriarty 2004), including some of the most buoyant: New Caledonia (de Garine-Wichatitsky et al. 2004), where the population is at least 120,000 (Desvals et al. 1992); Mauritius where numerous at circa 60,000, and an ecological problem (R.J. Safford in litt. 2008); Sulawesi and the Maluku islands (Indonesia; G. Semiadi pers. comm. 2008), Pulau Moyo (= Moyo island, a small island in the eastern part of Nusa Tenggara Timur, where deer are protected by local people; G. Semiadi pers. comm. 2008) and West Papua, Indonesia (over 8,000 estimated in Wasur National Park alone, in 1992; Anon. 1994). 4000 Javan Rusas were introduced from New Caledonia in the 1990s and are said to be expanding (Maudet 1999). There are sizeable populations (5,000 to 10,000 animals) located in New South Wales, Australia, and several small (<100 animals) wild herds in the coastal areas of Victoria, New South Wales and Queensland (Moriarty 2004). The Rusa population was estimated to be 16,000 in 2000 (Moriarty 2004). Wild herd sizes appear to be increasing, as indicated by encroachment of Rusas into peri-urban areas in Sydney and Brisbane. A small population of Javan Rusa was introduced to the North Island of New Zealand, which is reportedly unlikely to expand (Fraser et al. 2000).

Conversely, populations have decreased substantially in some areas on Java, where it is a native (Semiadi 2006), including Baluran National Park which (at least in the 1990s) held the largest Javan Rusa population within its natural range. In 1996, 2,500-3,000 Javan Rusas were counted during a census when multiple teams of observers deployed simultaneously throughout deer habitat (Anonymous 1996, S. Hedges pers. comm. 2008). Between 12 September 1998 and 18 January 1999, the population was thought to be greater than 1,000 head and it is very likely to have declined still further. Major declines have also occurred in Alas Purwo National Pak (S. Hedges pers. comm. 2008). Even in the 1980s-mid 1990s, Bali had very few populations, probably only one of significance: in Bali Barat National Park (S. Hedges pers. comm. 2008). There are probably no more than ten populations in the native range (= Java and Bali) and given the size of the Baluran population, it is implausible that there could be more than 10,000 mature individuals within the native range (which would imply a census population of about 13,000-20,000) even in the mid-1990s (S. Hedges pers. comm. 2008). In 2014 the native population is thought to have continued to decrease except for the herds in relatively well managed protected areas such as Ujung Kulon and Meru Betiri National Parks in Java, (G. Semiadi pers. comm. 2014). There are many more animals in the introduced range, but they are not counted for the purposes of categorizing the species based on population size and trend for the IUCN Red List.


Current Population Trend:Decreasing
Additional data:
Number of mature individuals:9999Continuing decline of mature individuals:Yes
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:This is essentially a tropical and subtropical grassland species (Medway 1977; Oka 1998) but is highly flexible, with successful populations in forests, mountains, shrublands and marshes (Whitehead 1993, Oka 1998, Rouys and Theuerkauf 2003, Keith and Pellow 2005). It is found from sea-level to 900 m asl (G. Semiadi pers. comm., S. Hedges pers. comm. 2008). Some subpopulations make seasonal movements; for example, on New Guinea numbers in the border area between West Papua and Papua New Guinea peak during the wet season, whereas in the dry season many move to the interior of Papua New Guinea (Semiadi 2006).

In diet it is adaptable, as indicated by its dentition and mouth shape (Dryden and Bisseling 1999), and will eat herbs, the leaves and bark of shrubs, and even seaweed (Kitchener et al. 1990, Oka 1998, Keith and Pellow 2005), although it seems to prefer certain types of grass (Kitchener et al. 1990, Oka 1998), including in its native range (S. Hedges pers. comm. 2008). In New Caledonia and Australia, it is a threat to native trees (de Garine-Wichatitsky et al. 2005, Keith and Pellow 2005). In the Torres Strait Islands, mating occurs during spring (September-October) and calves are born in autumn (April-May). In other parts of Australia, Javan Deer seems to breed at any time of the year, with a mating peak from late June to August, and a calving peak from March to April (Kitchener et al. 1990). In Indonesia it is said to breed all year around (Whitehead 1993), although a June-September increase in mating activity was found in Bali (Oka 1998), and in Java there is a peak of mating behaviour between July and September (S. Hedges pers. comm. 2008). Where hunting or other disturbance is not a big problem, Javan Deer are primarily diurnal, gathering in large groups in open areas at night. The rut tends to involve a lot of nocturnal activity, even in undisturbed/low hunting areas (Oka 1998, S. Hedges pers. comm. 2008 based on observations in East Java). Javan Deer are more social than their congeners (Kitchener et al. 1990). Herds are segregated by sex, except during the mating season, and may comprise up to 25 individuals (Kitchener et al. 1990).
Continuing decline in area, extent and/or quality of habitat:Yes
Generation Length (years):5

Use and Trade [top]

Use and Trade: The wild native population is hunted for food, medicinal products, and handicraft products. When taken from the wild, specimens are usually killed during the capture process, with the exception of some juveniles which may be kept as pets (Semiadi 2005). Commonly firearms are the weapon of choice for this type of game.

The species is commercially farmed in Australia, New Caledonia, Mauritius, Réunion, and Thailand (de Vos 1982, le Bel 1997) and has been farmed experimentally in Indonesia (Java) and Papua New Guinea (de Vos 1982, Tapari 1990). Farming is mainly for venison and velvet. It is also hunted for its meat (and velvet) in many parts of Indonesia, New Guinea and New Caledonia (Semiadi 2006). Is also a valued trophy animal for sport hunters in New Caledonia, New Guinea, New Zealand and Australia (Tapari 1990).

No figures are currently available as to the degree of significance of wild vs. domestic products in the market(s); or indeed whether such markets are the same or primarily independent from one another.

Threats [top]

Major Threat(s): Java has highly fragmented natural habitats and has done for centuries, reflecting long-standing high human population densities. Many protected areas were established during the Dutch colonial period but from independence up until the 1970s they were largely under-funded and neglected. After hosting the World Parks Conference in 1982, the Indonesian government gazetted a swathe of national parks and more structured conservation planning began, funded by the World Bank and other donors. The focus was largely on the 'multi-function' national parks and much money was spent on infrastructure, some staff training and increased personnel. The 'lesser' protected areas such as "wildlife reserves" and "nature reserves" still had few staff and resources, and that has continued to the present. There was some habitat loss from protected areas through illegal logging, agricultural encroachment and other offtake, but the national parks of Java (several of which contain ideal habitat for Javan Deer and, at least into the mid 1990s, very large populations) remained remarkably intact for much of the period. During the 1980s and early to mid 1990s guns were tightly controlled and the military and police were feared and respected. The strong culture of caged bird keeping meant that hunting, including that within protected areas, was primarily for birds and some small game, through various forms of trapping, including snaring. Thus there was relatively little hunting of Javan Deer and populations were stable or even increasing. Socio-political changes from 1997 led to a reduction in the respect for the police and military and the rise of a viewpoint that protected areas were the peoples' resources and would therefore benefit from decentralised management (M. Tyson pers. comm. 2008). This policy change, which risked a "tragedy of the commons", has indeed led to increased habitat destruction and poaching in the past decade. The Javan Deer, as a large deer, is particularly threatened by this rapid rise in illegal hunting (S. Hedges pers. comm. 2008) and also by expansion of agriculture on Java and other forms of encroachment (G. Semiadi pers. comm.; S. Hedges pers. comm. 2008.). In Java, this deer is poached with snares and dogs, but mostly with guns in the late 1990s and 2000s (S. Hedges pers. comm. 2008). The Javan Deer is now seen as a source of extra income and of animal protein by many local communities despite being legally protected (Semiadi 2006) and coupled with the decentralisation of conservation management decisions and actions, macro-economic fluctuations and reduced authority of The Law, this impedes control of illegal hunting (S. Hedges pers. comm. 2008). Poaching has reportedly reduced numbers at Baluran National Park, formerly the largest population within the native range, and more widely across Java, but data are insufficient to determine rate of decline (E. Meijaard pers. comm. 2008). Similar trends are likely on Bali. In the rest of its Indonesian range, e.g. Sulawesi, where it is introduced and thus populations are not used in assessing the Red List Category, it is also heavily hunted and there were major population declines in the late 1990s, although at least on Sulawesi the population is now in slow recovery (G. Semiadi pers. comm. 2008). Poaching of this species in its native range is for meat, medicinal products (some traded internationally), handicrafts products, and, locally, pets.

During the 1980s-1990s, when poaching and land conversion were relatively well under control in Javan national parks, the chief threat to the large population of Javan Deer in Baluran National Park was loss of grazing area to invasion by the introduced tree Acacia nilotica (Leguminosae) that converts open grassland to dense thorny scrub-forest. This plant was introduced (without adequate risk assessment) as part of an attempt to create a living fire-break around the park's grasslands, wild fire then being adjudged the major threat to the park's monsoon forests. Since that introduction, repeated cutting of the acacia has led to coppicing into very dense thickets that contain little or no grass or other herbs and are difficult for the deer to penetrate. Thus habitat loss and poaching are now serious limiting factors in Baluran National Park, and habitat loss/degradation remains a severe long-term threat to be addressed (S. Hedges pers. comm. 2008). Lantana camara (Verbenaceae) is also a problem in Javan Deer habitat in Baluran National Park and elsewhere on Java (S. Hedges pers. comm. 2008).

Conservation Actions [top]

Conservation Actions: Javan Deer occurs in several high-profile protected areas in Java. It is fully protected by Indonesian law. However, while surveillance of hunting has increased, urgent measures are still required within its native range to end poaching and to secure the protected areas in which it occurs. This will require the development of cooperative programmes and new partnerships with the local human communities.

Citation: Hedges, S., Duckworth, J.W., Timmins, R., Semiadi, G. & Dryden, G. 2015. Rusa timorensis. The IUCN Red List of Threatened Species 2015: e.T41789A22156866. . Downloaded on 24 September 2018.
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