Annamite Striped Rabbit (Nesolagus timminsi)

Annamite striped rabbits are very similar in appearance to their sister species, Sumatran striped rabbits (Nesolagus netscheri).

Descriptions of Nesolagus species are partly based on images made by camera traps. To capture the Sumatran striped rabbit, the cameras were set in the montane forests of Sumatra, while the Annamite Striped rabbit was seen in the Annamite mountain range of Laos and Vietnam.

Both species of striped rabbit have seven brown or black stripes and a red rump and white underside. They are the only species of rabbits to have stripes. Their fur is soft and dense, overlaid by longer, harsher hairs.

They are relatively small with a length of about 368–417 millimeters, with a tail of about 17 millimeters. Compared to members of the genus Lepus, Annamite striped rabbits have relatively short ears, tails, and limbs. Ear length of Nesolagus is about 43-45 millimeters (1.69-1.77 inches,) half that of those of most rabbits, such as those in the genus, Lepus. Their short limbs and relatively weak claws make them poor runners and burrowers.

However, several skull features distinguish the Annamite striped rabbit from the Sumatran striped rabbit. The Annamite striped rabbit’s foramen lacerum is smaller and narrower mediolaterally than that of the Sumatran striped rabbit. The Annamite’s P2 is 93% the length of P3 and has two folds on its anterior side, whereas the Sumatran’s P2 is only 73% the length of P3 with one fold. Lastly, the Annamite’s greatest skull length is 12% larger at 78.9 millimeters versus 70 millimeters.

Annamite striped rabbits have a relatively primitive dental structure with a dental formula: I 2/1 P 3/2 M 3/3, and a simplified paedomorphic pattern on P3.

The lifespan of Annamite striped rabbits is currently unknown.

BODY LENGTH

350-417 mm. / 13.8-16.4 in.

EAR LENGTH

43-45 mm. / 1.69-1.77 in.

TAIL LENGTH

17 mm. / 0.67 in.

DORSAL STRIPES

7

DENTAL FORMULA

I ²⁄1, C ⁰⁄0, P ³⁄2, M ³⁄3, ×2 = 28

LIFESPAN

3 yr.

LOCOMOTION

Plantigrade

The Annamite striped rabbit only recently became known to Western scientists. Striped rabbits were first observed, captured and being offered for sale in a food market in the rural town of Bak Lak in Laos in 1995 by biologist, Rob Timmins. Not long after this, the rabbit was confirmed to exist in Vietnam. The species was described by Alison K. Surridge in 1999 and named after Timmins’ find.The Annamite striped rabbit is one of three species in the monophyletic Nesolagus genus of rabbits, as well as the Sumatran striped rabbit (Nesolagus netscheri) and the extinct species Nesolagus sinensis that lived in China in the early Pleistocene age.

Due to the small number of individuals, and because of the rare sightings of this genus, there is not much information available on its behavior. Overall there is very little known about the genus as a whole, most information coming from the Sumatran rabbit. One thing that we do know however, is that the Sumatran rabbit is nocturnal and hides out in burrows which it does not make itself and does not really like to go out looking for food for itself in places that are too far from its home.

Striped rabbits are found in only four locations. The Sumatran striped rabbit has been found in the Barisan Mountains in western Sumatra, Indonesia, and the Annamite striped rabbit has been found in the Annamite mountains on the border between Vietnam and Laos. The fossils, parts of the left mandible with several teeth, of the extinct Nesolagus sinensis were found in Chongzou Ecological Park in the Guangnxi Zhuang region of southwest China.

Very little is known of the The Annamite striped rabbit’s ecology, nor why there is a thousand-mile gap between it and its sister species, the Sumatran striped rabbit. Molecular analysis indicates that the two diverged from a common ancestor about eight million years ago. They may have survived in forested refugia that remained when glacial ice sheets retreated after the last ice age. Both morphological and genetic data support species-level distinction from the Sumatran striped rabbit.

The Annamite striped rabbit is in the Leporidae family of rabbits and hares, containing over 60 species of extant mammals in all. Various countries across all continents except Antarctica and Australia have indigenous species of Leporidae. Furthermore, rabbits, most significantly the European rabbit, (Oryctolagus cuniculus), have been introduced to most of Oceania and to many other islands where they pose serious ecological and commercial threats.

The Annamite striped rabbit has no recognized subspecies.

KINGDOM

Animalia

PHYLUM

Chordata

CLASS

Mammalia

ORDER

Lagomorpha

FAMILY

Leporidae

GENUS

Nesolagus

SPECIES

timminsi

SUBSPECIES

None

The Annamite striped rabbit is named for its striped appearance and native region in the Annamite Mountain range. Along with the Sumatran striped rabbit (Nesolagus netscheri), the Annamite striped rabbit is the only species of rabbit to have stripes.

The Annamite striped rabbit’s common name, rabbit, usually applies to all genera in the Leporidae family, except Lepus, as almost half the members of Lepus are usually called hares. Like most common names however, the distinction does not match current taxonomy completely; jackrabbits are members of Lepus, and members of the genera Pronolagus and Caprolagus are sometimes are called hares.

The Latin word Leporidae, the Annamite striped rabbit’s family, translates to those that resemble lepus, or hare.

GROUP

Colony, Fluffle, Warren

MALE

Buck

FEMALE

Doe

YOUNG

Kitten

The Annamite striped rabbit occurs at low and medium altitudes in the northern and central Annamite Mountains along the Viet Nam and Lao PDR border. In Viet Nam, it is believed to occur in six provinces: Nghe An, Ha Tinh, Quang Binh, Quang Tri, Thua Thien Hue and Quang Nam. In Lao PDR it is believed to occur also in six provinces: Xiangkhouang (unconfirmed), Bolikhamxai, Khammouan, Savannakhet, Salavan and Xekong. They are found from the Pu Mat Nature Reserve to Phong Nha-Ke Bang National Park.

There are no records from the southern parts of the central Annamites or from the southern Annamites but these regions are not obviously ecologically unsuitable. The westward extent of occurrence in Lao PDR appears to be tied closely to localized climactic factors, with all indications suggesting that the species is strongly associated with wet evergreen forest. Fitting this, it has been confirmed in the Lao PDR only in areas close to the border with Viet Nam: a pattern shown by various other wet evergreen forest indicator species.

The Annamite ridge forms most of the international border between the two countries and places most of Lao PDR in the rain-shadow of moisture-laden air masses from Viet Nam in the Lao dry
season. The vast majority of habitat suitable for Annamite striped rabbit is therefore in Viet Nam. Most records come from below 1,000 meters and the species has been recorded nearly down to 50 meters above sea level, although few low-altitude areas retain otherwise suitable habitat. The highest record traced was at 1,300 meters above sea level.

EXTANT

Laos, Vietnam

Annamite striped rabbits live in subtropical/tropical moist lowland forests and rainforests.

The specific range of elevations the rabbits inhabit is currently unknown, but their sister species, Sumatran striped rabbits (Nesolagus netscheri) are found from 600 to 1400 meters above sea level. Annamite striped rabbits have been found within this range except one specimen that was found at an altitude of 200 meters.

It is clear that the Annamite striped rabbit occurs predominantly in wet evergreen forest, which has little-to-no dry season, probably no month with rainfall below 40 millimeters. Most records come from low- to mid-elevation broadleaf forest.

As an example of typical Annamite striped rabbit occurrence patterns, camera-trapping in three protected areas in Viet Nam, Phong Dien Nature Reserve (=NR), Khe Nuoc Trong proposed NR and Bac Huong Hoa NR, detected the rabbit in broadleaf, wet evergreen forest from 50 to 1,183 meters above sea level. There is one record in Viet Nam from close to the highest point in Bach Ma NP in forest with characteristics approaching montane evergreen forest, but still with an ever-wet climate. One record in Lao PDR comes from the western portion of Xe Sap NPA where semi-evergreen and lower montane forests predominate; however, intensive and extensive camera-trapping showed that the species is very localized and/or very rare in western Xe Sap NPA. The localized presence of Licuala and Lanonia palm species indicates small patches of ‘ever-wet’ habitat in this area and the lower montane forest areas with a considerable Dalat Pine Pinus dalatensis component are another clear indication that these lower montane forests have reduced dry seasons compared with most such forests in Lao PDR.

Although the Annamite striped rabbit has potentially a low detectability by camera-trapping as conventionally practiced in Indochina, it appears to have been detected by all camera-trapping efforts of more than a few thousand camera-trap-nights in wet evergreen forest.

In stark contrast, it has never been camera-trapped by surveys of similar effort in areas of indisputable semi-evergreen and lower montane forest in Lao PDR. Particularly telling in this regard are the absence of detections from Nam Et – Phou Louey NPA, Nam Kading NPA, the Nam Ngiap catchment, the Nam Xang – Nam Chouan area, Phou Sithon ESCA, large regions of Nakai – Nam Theun NPA, and much of western Xe Sap NPA. These are all areas with varying degrees of Annamite faunal affinity. In Nakai – Nam Theun NPA the few detections were all in sites where, as with Xe Sap NPA, other indications suggest localized occurrence of wet evergreen forest (or forest strongly transitional with it).

Potentially, many Lao populations function as sink populations, because most if not all wet evergreen forest in Lao PDR is likely to be to some extent transitional with drier semi-evergreen and lower montane forests, and thus is presumably suboptimal for this rabbit.

Camera-trapping from the Hue SNR in central Viet Nam suggests that the species survives in secondary and heavily degraded forest.

There is one report of Annamite Striped Rabbit occurrence far from wet evergreen forest, in western Khammouan province, Lao PDR. This was based upon the presentation of an image of the rabbit to local villagers and a positive response from the villagers that the animal was present in their area. However, other independent evidence indicates that identification of animal images (including mammals as distinctive as the tiger (Panthera tigris) and the saola (Pseudoryx nghetinhensis)) by local villagers is often not reliable. The area reported is a mosaic of karst and rural agriculture, far from wet evergreen forest. Occurrence in this area would, if confirmed, represent a substantial increase in the species’ known range, and would require a comprehensive rethink of biogeographic patterns of occurrence of not only this species, but other Annamite associates as well. On this survey, it was also reported that they found small leporid tracks, and that villagers stated that the animal with which they identified as the Annamite striped rabbit was common in the area and an occasional pest of rice fields. Factors contesting occurrence in this region are the lack of any evidence of Annamite striped rabbit in western Lao PDR despite extensive camera-trapping and the absence of trade records of it in the several fresh wildlife meat markets around Khammouan’s western karst. Kha-nyou Laonastes aenigmamus and several other small mammal species of karst are found in these markets quite frequently. There is no confirmation from anywhere in its range of Annamite striped rabbit occurrence in any habitat remote from wet evergreen forest.

FOREST

Subtropical/Tropical Moist Lowland

Along with the Sumatran striped rabbit (Nesolagus netscheri), the Annamite striped rabbit is the most elusive lagomorph known to science. To date, no scientific studies have focused on the ecology, range, or population status of the Annamite striped rabbit. Nonetheless, some general natural history traits can be surmised from camera-trap records and villager information. As such, little is known about the home range of Annamite striped rabbits and how they communicate and perceive the world.

Annamite striped rabbits appear to be strictly nocturnal and rest during the day in burrows made by other animals. Their short limbs and relatively weak claws make them poor runners and burrowers. Camera-trap records from seven protected areas in the central Annamites (Bach Ma NP, the Hue and Quang Nam SNRs, Phong Dien NR, Khe Nuoc Trong proposed NR, Bac Huong Hoa NR, and Xe Sap NPA) were exclusively at night.

The Annamite striped rabbit appears to be solitary. Systematic camera-trapping in Bach Ma NP, the Hue and Quang Nam SNRs, and Xe Sap NPA showed predominantly lone individuals, with only two exceptions, both of duos.

CIRCADIAN RHYTHM

Nocturnal

MOVEMENT PATTERN

Non-Migrant

The specific diet of Annamite striped rabbits is not yet known.

Its sister species, the Sumatran striped rabbit (Nesolagus netscheri), feeds at night on plants that make up the forest understory. They remain hidden in the understory while foraging rather than foraging in exposed clearings.

All lagomorphs are herbivores that use hindgut fermentation to metabolize food. They also reingest their own soft feces in order to extract remaining nutrients.

PREFERENCE

Generalist

STYLE

Forager

Almost nothing is known regarding the reproduction of Annamite striped rabbits or its sister species, Sumatran striped rabbits (Nesolagus netscheri), as few individuals have been observed.

As mammals, mother Annamite striped rabbits are assumed to provide nourishment until weaning.

A duo of kittens, estimated to be approximately one week old, was found in a shallow burrow in Phou Chomvoy Provincial Protected Area, Bolikhamxai province, Lao PDR, during the month of January. A second duo of kittens, estimated to be 10–12 weeks of age, were found in Pu Mat NP in the month of May.

BREEDING SEASON

January-May

PARENTAL INVESTMENT

Maternal

BIRTHING SEASON

January-May

LITTER

1-2

The impact of Annamite striped rabbits on their ecosystem is unknown. As herbivores, they may act as seed dispersers.Natural predators of Annamite striped rabbits are widely unknown, though they are trapped by hunters in the Annamite Mountains.

Annamite striped rabbits are killed in ground snares along hunting lines. They are less likely hunted by dogs that accompany hunters.

There are no known adverse effects of Annamite striped rabbits on humans, though there have been reports by local villagers of the rabbit as a pest of rice fields in western Khammouan province, Lao PDR. These reports were based upon the presentation of an image of the rabbit to local villagers and a positive response from the villagers that the animal was present in their area. However, other independent evidence indicates that identification of animal images (including mammals as distinctive as the tiger (Panthera tigris) and the saola (Pseudoryx nghetinhensis)) by local villagers is often not reliable.

Annamite striped rabbits have been used as a source of food and income by local residents of the Annamite Mountains in Laos and Vietnam. This species was first discovered being sold in a food market in Ban Lak, Laos between December 1995 and February 1996.

Although there is no evidence of a targeted trade for the Annamite striped rabbit, it is certainly hunted as part of the thriving wildlife trade that occurs across its known range. Given the paucity of information suggesting that the species has a high value for wildlife trade, it is likely that when caught, it often ends up in the local fresh wildlife meat markets, or is used for primary consumption. In fact, the first evidence of the rabbit in mainland South-east Asia came from a subsistence market in rural Lao PDR.

FOOD

Local, National

Records show Annamite striped rabbits can be common in suitable habitats and other areas show as uncommon and rare.

Only ten specimens have ever been collected and only a single live rabbit has been photographed in nature.

Although population size and density have not been established anywhere in its range, the Annamite striped rabbit appears to be noticeably less abundant in heavily hunted areas than in areas perceived on the basis of other evidence to have had lower hunting intensity.

Observations and estimates of the intensity of hunting pressure across the species’ known and presumed distribution in both range states indicates that at a landscape level this pressure is extremely high, with episodic deployment of snares in the region of dozens to hundreds of snares per square kilometer over periods of years within almost every square kilometer of suitable habitat in these landscapes.

Although clear quantification of population size or decline rates is not possible, subjective assessment of available evidence, from camera-trapping of this species and trends in conservation status of other species in the same areas, suggests that substantial range-wide declines are very likely to have occurred.

The clearest and most compelling information on the population trend of Annamite striped rabbit comes from a camera-trapping project in central Viet Nam. Because camera-trapping as conventionally practiced in Indochina is often targeted at animals much larger than rabbits, and for a variety of objectives, there is wide variation in its ability to detect this rabbit reliably. During this specific camera-trapping project in central Viet Nam the cameras were set consistently low enough to record rabbit-sized ground-dwelling mammal species reliably. Systematic such camera-trapping (totaling 6,805 camera-trap-nights) in Bach Ma National Park (=NP) in 2014-2015 at 53 camera-trap stations evenly spaced across the national park detected Annamite striped rabbits at only four (7.5%) of the stations, with a total of seven detections (defined as images of the species separated by at least 60 minutes from the previous image of the species at the same station). Most records came from the more remote and rugged parts of the protected area. More intensive camera-trapping in a core part of the protected area, at finer spatial scale, failed to record the species at 64 stations (8,256 camera-trap-nights), indicating that the species is either extremely rare or extirpated in this part of the protected area.

Camera-trapping in the Hue and Quang Nam Saola Nature Reserves (=SNRs), two contiguous protected areas adjacent to Bach Ma NP, conducted immediately after the Bach Ma NP survey, detected the species more often. It was recorded at 10 of 39 stations with camera-traps spaced systematically over the protected areas, in a total of 5,933 camera-trap-nights, comprising 47 detections. The detection of Annamite striped rabbits at 25.6% of the camera-trap stations is far higher than in the landscape-scale camera-trapping in Bach Ma NP, but well below the occupancy of other mammals generally taken to be more resilient to hunting, such as ferret badgers (Melogale). A further 54 detections, from 14 of 64 stations, was obtained in an intensive effort in the reserves’ core. This intensive camera-trapping recorded a minimum of 27 individuals, as identified by their unique striping patterns. Unlike Bach Ma NP, the Hue and Quang Nam SNRs have some level of anti-poaching support (although snaring persists at high levels nonetheless), which could indicate that Annamite striped rabbit may be able to rebound in the presence of targeted anti-snaring efforts. However, no baseline survey was conducted in this area before anti-poaching activities began, so the population trend remains speculative.

In 2011, Dr. Tom Gilbert, of the University of Copenhagen, decided to test if mammals could be detected by sequencing the host blood found in terrestrial leeches. Nicholas Wilkinson, a fellow member of the Saola Working Group and Cambridge PhD student, collected 25 jungle leeches in the forests of central Vietnam and sent them to Dr. Gilbert’s lab. Surprisingly, 21 of the 25 leeches yielded amplifiable mammalian DNA. The results showed that the leeches had fed on several common species, including pig and serow, but had also dined on some rare and elusive Annamite endemics, including Annamite striped rabbit and Annamite muntjac (Muntiacus truongsonensis), two of the most secretive mammal species in Southeast Asia. Notably, the Annamite striped rabbit had not been detected in over 200 nights of camera trapping effort in the survey area, indicating the power this method has for detecting rare species. Not surprisingly, these results caused a stir in the biological world; utilizing this new technique could revolutionize the way biodiversity surveys are conducted in the tropical forests of Asia. As such, leeches offer one of the best options for detecting and monitoring the Annamite striped rabbit. Terrestrial leeches can be used to study the distribution and habitat preferences of the Annamites mammal community, specifically the little-known and elusive endemics. Although leeches are a good option, it can take a long time to receive results as the collected leeches have to make an overland journey to China for analysis.

FRAGMENTATION

Not Fragmented

Threats to the Annamite striped rabbit are hunting, either by snare or dogs, and habitat loss due to agriculture and logging, which makes it more vulnerable to hunters. The most significant threats are snares and cultivation at lower altitudes and agriculture throughout the rabbit’s range. The least, but increasing, threats are extensive road building which opens undisturbed area to farmers and timber harvesters, dams, and mining.

Although habitat loss and degradation have undoubtedly been factors in Annamite striped rabbit population declines from historical levels, the primary threat to the species is the intensive snaring that occurs across Annamite forests, and which is especially high in northern and central Viet Nam (which areas comprise most of the species known range). It is difficult to convey the intensity of snaring in the Annamites. In many protected areas, hundreds of snares can be collected in a single day’s walk, and elaborate brush-fence-style snare lines can reach several kilometers in length.

AGRICULTURE & AQUACULTURE

Annual & Perennial Non-Timber Crops, Wood & Pulp Plantations

ENERGY PRODUCTION & MINING

Mining & Quarrying

TRANSPORTATION & SERVICE CORRIDORS

Roads & Railroads

BIOLOGICAL RESOURCE USE

Hunting & Trapping Terrestrial Animals, Gathering Terrestrial Plants, Logging & Wood Harvesting

NATURAL SYSTEM MODIFICATIONS

Dams & Water Management/Use

The Annamite striped rabbit is found in conservation areas Phong Nha-Kẻ Bàng National Park, Nakai–Nam Theun, and Umat, within their natural geographic range. They are also found in the Vietnam provincial protected area Nam Chat/Nam Pan and Xe Sap in Laos. Unfortunately, protected areas across the species’ range remain little more than paper parks, and if the species is to survive in the wild, this situation must change fundamentally. Most other protected areas known or likely to hold the species are probably at least as exploited and as of 2018 receive minimal law enforcement effort or snare removal.

As with other rare and threatened ground-dwelling Annamite endemic mammal species, the highest priority for Annamite striped rabbit is effective law enforcement to curtail the industrial-level snaring that occurs across the region, combined with efforts to reduce the demand for wildlife meat and products sold as medicines, the ultimate driver of snaring throughout the Annamites amongst the increasing middle classes in Viet Nam, Lao PDR, and further afield. Whether or not this rabbit is ever traded further afield does not affect the merit of this recommendation, as it is simply one species among a large general catch, driven by market demand in not just Lao PDR and Viet Nam.

The challenges to enacting effective protected area-based law enforcement are substantial: neither Viet Nam nor Lao PDR has a historical model upon which to base effective protected area management, and government support remains weak, involving laws and decrees that have, typically, little follow-up action. The Vietnamese and Laotian governments do not presently maintain any conservation plans for the Annamite striped rabbit.

Some success has been achieved by joint government- and NGO-led snare-removal teams operating in the Hue and Quang Nam SNRs in Viet Nam and in neighboring Xe Sap NPA in Lao PDR, operating under the direction of the WWF Carbon and Biodiversity (CarBi) project. Over a five-year period, these patrols have removed more than 75,000 snares from the SNRs and the eastern section of Xe Sap NPA.

Notable as these achievements are, the level of snaring in all three protected areas remains extremely high, with snaring intensity plausibly reaching thousands of snare-nights per square kilometer per year. Therefore, although this joint management model provides some hope for future protection for Annamite striped rabbit from intensive snaring in at least one forest block, considerable increase in effectiveness is needed before any part of this forest complex could be considered safe for the species or any other ground-dwelling Annamite endemic mammal.

Because of the challenges that remain in the effective management of protected area of the Annamite striped rabbit’s range, it is vital that conservation stakeholders consider within the next few years the establishment of a captive insurance population of this species. Currently, the rabbit is not held in captivity.

Although it is true that the urgency to establish an insurance population of Annamite striped rabbit is lower than for some other Annamite endemic mammals, notably saola (Pseudoryx nghetinhensis), it would be prudent to secure an ex situ population of Annamite striped rabbit in the near future as the general snaring-driven declines are unlikely to slow in coming years. Establishing a captive population for Annamite striped rabbit should be less difficult than for the much larger and rarer saola. Unlike the saola, the rabbit still exists in detectable densities within several forest blocks in both Viet Nam and Lao PDR, and it should be much easier to capture, in part because of its habitat of becoming immobile when encountered with a headlamp at night. Indeed, as long as proper international expertise to oversee the care of captured individuals can be secured, there seems little downside in establishing an insurance population sooner rather than later.