Mammalia 2019; aop Short Note Arum Setiawan, Muhammad Iqbal*, Amran Halim*, Rio Firman Saputra*, Doni Setiawan and Indra Yustian First description of an immature Sumatran striped rabbit (Nesolagus netscheri), with special reference to the wildlife trade in South Sumatra https://doi.org/10.1515/mammalia-2018-0217 Received December 25, 2018; accepted September 5, 2019 Abstract: The Sumatran striped rabbit (Nesolagus netscheri Schlegel, 1880) is the least known lagomorph in the world. This paper describes the first record of a young N. netscheri that was offered for sale (the size is approximately 52–56% of the adult), together with an adult, by a social media group in February 2018. The rabbits were reportedly obtained from the Dempo mountain, South Sumatra. Compared to previous descriptions of N. netscheri, the Dempo mountain specimens have longer ears (47–52 mm vs. 34–50 mm), shorter tails (9–15 mm vs. 17 mm) and shorter hindfeet (60–65 mm vs. 67–87 mm). The threats to N. netscheri are revisited and discussed. Keywords: hunting; juvenile; morphology; Nesolagus netscheri; South Sumatra; Sumatran striped rabbit. The Sumatran striped rabbit (Nesolagus netscheri Schlegel, 1880) is allegedly the rarest lagomorph in the world. Nesolagus netscheri is endemic to Indonesia, and classified as Vulnerable on the International Union for Conservation of Nature (IUCN) Red List (Meijaard and Sugardjito 2008, Schai-Braun and Hackländer 2016). Only a dozen museum specimens collected between 1880 and 1916 and camera trap records show that this species is very scarce (Jacobson 1921, Flux 1990, Surridge et al. 1999, Hoffmann and Smith 2005, Dinets 2010, McCarthy et al. 2012). This rare rabbit occupies dense forest at moderate *Corresponding authors: Muhammad Iqbal, Amran Halim and Rio Firman Saputra, Conservation Biology Program, Faculty of Science, Sriwijaya University, Jalan Padang Selasa 524, Palembang, Sumatera Selatan 30129, Indonesia, e-mail: kpbsos26@yahoo.com (M. Iqbal); amranhalim11@gmail.com (A. Halim); riofirman4@gmail.com (R.F. Saputra) Arum Setiawan, Doni Setiawan and Indra Yustian: Department of Biology, Faculty of Science, Sriwijaya University, Jalan Raya PalembangPrabumulih km 32, Indralaya, Sumatera Selatan 30862, Indonesia elevations in Sumatra, a habitat that is under increasing development pressure. There is an urgent need to better understand N. netscheri, and the current threats in order to inform conservation and management strategies (Smith 2008, Smith et al. 2018). The most recent sighting of Nesolagus netscheri was from the Gunung Raya Wildlife Reserve. Interviews with locals indicated that hunting was a major threat (Setiawan et al. 2018). After a field survey and exploration of local knowledge of N. netscheri in the Gunung Raya Wildlife Reserve (Setiawan et al. 2018), we continued to learn about N. netscheri in South Sumatra. Recently, we began following various social media groups which focus on wildlife trading. In a private WhatsApp group, we received information on two individuals of N. netscheri, one of which was a young rabbit. From the discussions among the members, it appeared that N. netscheri is greatly desired by collectors. On 14 February 2018, a young Nesolagus netscheri was offered for sale on WhatsApp. This individual was reportedly caught from a forest within the Dempo mountain, South Sumatra province. The size is ca. 52–56% of the adult (Figure 1). Unfortunately, this individual died a few days later. As very little information is available on young N. netscheri and its reproduction, we requested the seller to donate the specimen. On 20 February 2018, the same seller offered an adult of N. netscheri. This individual also died after a few days. It was caught from the same area as the young N. netscheri. We also requested this specimen from the seller, and it was finally received on 23 February 2018. The specimens were deposited in the biology museum of Gadjah Mada University, with voucher catalog Musbio/Mam/Deposit/Coll.01.28112018. Measurements of the Nesolagus netscheri from South Sumatra and previous available data are presented in Table 1. Nesolagus netscheri is about the size of the European rabbit (Flux 1990). The young N. netscheri has a body length of 220 mm (Table 1). This size is between one-third Brought to you by | Lund University Libraries Authenticated Download Date | 11/6/19 4:44 AM 2 A. Setiawan et al.: Immature Nesolagus netscheri in Sumatra Figure 1: A young Nesolagus netscheri when it appeared for the first time for sale on 14 February 2018. Table 1: Measurements of Nesolagus netscheri. Characteristics Head-body (mm) Tail (mm) Ear (mm) Hindfoot (mm) Weight (kg) YN AN Fl SH 220 9 47 60 0.32 390 15 52 65 1.5 368–417 17 34–45 67–87 1.5 370–420 17 30–50 67–87 1.5 YN, Young Nesolagus netscheri; AN, adult Nesolagus netscheri; Fl, Flux 1990; McCarthy et al. 2018; SH, Schai-Braun and Hackländer 2016. and one-half (1/3–1/2) of the adult of N. netscheri (368– 420 mm). Comparison of N. netscheri specimens from the Dempo mountain with previously available specimens suggests that specimens from the Dempo mountain have longer ears (47–52 mm vs. 34–50 mm), shorter tails (9–15 mm vs. 17 mm) and shorter hindfeet (60–65 mm vs. 67–87 mm). Although only two individuals were measured, the different morphological characteristics are interesting. Further investigation is needed to study the morphological differences of N. netscheri populations between the sites in Sumatra. At present, it is regarded as a monotypic species (Flux 1990, Schai-Braun and Hackländer 2016, McCarthy et al. 2018); but if the listed characteristic differences are significant and if it occupies rich soils in isolated volcanic areas, it could be possible that the Dempo mountain population represents a distinct subspecies. Some tissues are needed for DNA analyses to examine the northern and southern populations of N. netscheri to test the hypothesis if there is a difference in characteristics between them. All previous information on the morphometrics of Nesolagus netscheri is from adult individuals, and there is no information for young or juvenile individuals (Flux 1990, Schai-Braun and Hackländer 2016). The only recent observation of young N. netscheri was reported by Setiawan et al. (2018), and no previous information is available on breeding. We previously reported a young N. netscheri from the Dempo mountain, and in February, sightings of young and adult ones from the Gunung Raya Wildlife Reserve were reported (Setiawan et al. 2018). In some genera of lagomorphs, e.g. Nesolagus, Pronolagus and Caprolagus, little or nothing about reproduction is known. However, repeated observations of young N. netscheri in February suggest that N. netscheri might breed between December and February. In European rabbits which are nearly the same size, the gestation is ca. 4–5 weeks and nursing ca. 4 weeks (Schai-Braun and Hackländer 2016). With reference to colors and morphological measurements, the color of Nesolagus netscheri is apparently variable among individuals, and stripes might be absent in the front or much reduced (Flux 1990, Schai-Braun and Hackländer 2016). The color of the young Sumatran striped rabbit from the Dempo mountain is consistent with that of the adult: having black ears and conspicuous wide black or dark brown stripes on a yellowish gray background that become rusty brown toward the rear, the ventral fur and the chin; and the inside of the legs are whitish (Flux 1990, Francis 2001, Schai-Braun and Hackländer 2016). However, this young individual looked significantly darker than the adult (Figures 1 and 2). Through the monitoring of Nesolagus netscheri on a private WhatsApp group, comprising local south Sumatran hunters and wildlife traders, we found that five individuals of N. netscheri were trapped during 2017, and three individuals between January and March 2018 – a total of Figure 2: An adult Nesolagus netscheri when it appeared for the first time for sale on 20 February 2018. Brought to you by | Lund University Libraries Authenticated Download Date | 11/6/19 4:44 AM A. Setiawan et al.: Immature Nesolagus netscheri in Sumatra eight individuals between 2017 and 2018. According to the trappers, all individuals were collected from the highlands around the Dempo mountain of South Sumatra. After receiving a rabbit from a local trapper, a collector will offer the N. netscheri for sale. Quoted sales prices are Rp 5.000.000 (or $365), the price includes shipping within South Sumatra; and Rp 7.000.000 (or $510), including the shipping cost to Java. The data obtained from the trading group suggest that N. netscheri is a favored species based on its rarity, and the ease of smuggling due to its similarity to a domestic rabbit. The Nesolagus netscheri reported for sale in this WhatsApp group is a bycatch of hunting mouse-deer Tragulus sp., using snares for trapping, and cassava as the bait. Blouch (1984) suggested that Nesolagus netscheri was not subjected to much hunting pressure, probably because they naturally occur at low densities and in remotes areas. In addition, Meijaard and Sugardjito (2008) stated that the main threat to N. netscheri is the clearing of mountain forest for agriculture, primarily coffee, tea and cocoa plantations; and it is not apparently hunted routinely, probably due to its natural rarity; 30 years later, now, many highland forested areas have become more accessible and communication technologies allow information exchange between hunters, wildlife traders and collectors. Poaching in many of the protected areas of Sumatra is a major threat to N. netscheri, alongside deforestation and human encroachment (Schai-Braun and Hackländer 2016). Information from local people in the Gunung Raya Wildlife Reserve of South Sumatra suggests that the fact that overseas collectors are prepared to pay high prices may be a new, additional and very worrying threat to N. netscheri (Setiawan et al. 2018). It is necessary to take urgent action to ensure Nesolagus netscheri continues to survive in the highland forest of Sumatra ecosystems. There is much we do not know, and what little we do know about many of the species highlighted earlier is frightening. Further field studies, monitoring of social media platforms dealing with hunting and wildlife trading, conservation awareness and regular field patrols by park managers are needed, to ensure local populations of N. netscheri can survive in the wild. Acknowledgments: We thank Sriwijaya University for providing grants to the first and last authors known as “Hibah Profesi”. We are very grateful to the Biology Museum of Gadjah Mada University who preserved our specimens. We express our gratitude to John Flux [IUCN Species Survival Commission (SSC) Lagomorph Specialist Group] and 3 Debby Ng for editing the English language and improving this draft. 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Mammal species of the world – a taxonomic and geographic reference, Third ed. Johns Hopkins University, Baltimore. pp. 185–211. Jacobson, E. 1921. Notes on some mammals from Sumatra. J. Fed. Malay States Mus. 10: 235–240. McCarthy, J.L., T.K. Fuller, K.P. McCarthy, H.T. Wibisono and M.C. Livolsi. 2012. Using camera trap photos and direct sightings to identify possible refugia for the Vulnerable Sumatran striped rabbit Nesolagus netscheri. Oryx 46: 438–441. McCarthy, J.L., J. Holden and D. Martyr. 2018. Nesolagus netscheri (Schlegel, 1880) Sumatran striped rabbit. In: (A.T. Smith, C.H. Johnston, P.C. Alves and K. Hacklander eds.) Lagomorphs: pikas, rabbits, and hares of the world. Johns Hopkins University Press, Baltimore. pp. 95–97. Meijaard, E. and J. Sugardjito. 2008. Nesolagus netscheri. The IUCN Red List of Threatened Species 2008. Available at: www. iucnredlist.org (Downloaded on 02 May 2017). Schai-Braun, S.C. and K. Hackländer. 2016. Family Leporidae (Hares and rabbits). 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