Paul Carter, posted 26 Sep 2024.
Minor edits on 10 Oct 2024 do not include any changes to species identification.
Summary
On a six-day visit (7-12 Sep 2024) with Ian Thompson to the Toloulaggo Village area on Siberut Island we saw 12 mammal species of which 11 were endemic to the Mentawai Islands, as well as another 4 species without confirmed identification. Highlights were: Golden-bellied Treeshrew, Kloss’s Gibbon, Siberut Langur, Mentawai Long-tailed Giant Rat and Siberut Flying Squirrel. We also saw what appears to be Sipora Flying Squirrel, noting that literature and databases do not include Siberut in range for this species.
Siberut Island is in the Mentawai Islands off western Sumatra. We stayed in Toloulaggo village and visited only the degraded forest within 2 km of the village. Ian arranged the trip through Wawan (Arif Setiawan) of SwaraOwa; our two local guides were Ismael Saumanuk and Vinsensius Tateburuk (Vincent), assisted by Franky.
Update (Oct): Ian has now posted a trip report (including Siberut, mainland Sumata and Java).
Contents
A. Mammal List
B. Mammal Images and Notes
C. Reptile List
D. Notable Bird Records
E. Trip Data and Logistics
F. References
Abbreviations: PH – Photographed; NP – Not Photographed; iNat – www.iNaturalist com.
iNat links: This post includes iNat links for some records because (1) there may be other comments or alternative identifications posted there and not yet revised here, and (2) I sometimes post more images at iNat than in the report below (to avoid image clutter).
A. Mammal List
- Golden-bellied Treeshrew (Tupaia chrysogaster). PH.
- Siberut Langur (Presbytis siberu). PH.
- Pig-tailed Langur (Simias concolor). PH.
- Kloss’s Gibbon (Hylobates klossii). PH.
- Philippine Palm Civet (Paradoxurus philippinensis) ssp: “Mentawai Palm Civet” (Paradoxurus philippinensis lignicolor). PH.
- Siberut Flying Squirrel (Petinomys lugens). PH.
- Sipora Flying Squirrel (Hylopetes sipora). PH.
- Mentawai Three-striped Squirrel (Lariscus obscurus). PH.
- Mentawai Squirrel (Callosciurus melanogaster). NP.
- Fraternal Squirrel (Sundasciurus fraterculus). PH.
- Mentawai Long-tailed Giant Rat (Leopoldamys siporanus). PH.
- Mentawai Rat (Rattus lugens). PH.
RECORDS WITH PROVISIONAL IDENTIFICATION ONLY:
- Mentawai Spiny Rat (Maxomys pagensis). PH.
- Asian Whiskered Myotis (Myotis muricola). NP. Seen just before sunset.
- Greater Short-nosed Fruit Bat (Cynopterus sphinx). NP. A large Cynopterus feeding on fruit trees in the village.
- Lesser Short-nosed Fruit Bat (Cynopterus brachyotis). PH. Smaller-looking Cynopterus roosting under palm tree fronds.
MAMMALS SEEN ON THE PADANG-SIBERUT CROSSINGS:
Dolphin sp. NP. We saw a group of about six dolphin porpoising about 15 km off Padang, somewhere around Pulau Bindalang (?), at about 5.30 PM when returning to Padang. They were small, slender and dark grey above, a bit lighter grey below. They did not appear to be Common Dolphin or Bottlenose Dolphin. Pantropical Spotted Dolphin (Stenella attenuata) might be the closest fit; identification not confirmed.
B. Mammal Images and Notes
Golden-bellied Treeshrew (Tupaia chrysogaster). PH. Seen a few times.
Siberut Langur (Presbytis siberu). PH. Two sightings on the logging trail, a single at night and a small group one morning.
Kloss’s Gibbon (Hylobates klossii). PH. Two sightings on the logging trail; both groups were calling.
Pig-tailed Langur (Simias concolor). PH. One very distant sighting on the logging trail loop (an excellent spot by the guides) of one dark morph grooming a pale rufous morph.
Philippine Palm Civet (Paradoxurus philippinensis) ssp: “Mentawai Palm Civet” (Paradoxurus philippinensis lignicolor). PH. Two good sightings, found by IT. Sep 8 (iNat post) and Sep 11 (iNat post).
Siberut Flying Squirrel (Petinomys lugens). PH. Common. Images below on Sep 11 show one eating banana blossom: iNat post. The second image below shows the characteristic three or four whiskers on a hidden wart behind the eye.
Sipora Flying Squirrel (Hylopetes sipora). PH. One seen with white-tipped tail and two others that looked similar but without white-tipped tails and one had grey cheeks, the others having pale to slightly buffy cheeks. iNat posts (a) Sep 8 @ 1925 (dark-tipped tail, pale cheeks) and (b) Sep 10 @ 1856 (with white tail tip), 2 images shown below. Literature and databases do not show Sipora Flying Squirrel in range on Siberut, but Wawan and our guides were aware that there were two species of flying squirrel in the area, with one smaller than Siberut Flying Squirrel and with a paler/whiter venter.
Mentawai Three-striped Squirrel (Lariscus obscurus). PH. Three seen on a side-trail off the School Track; a pair found by Ismael and Vincent after we went looking for them on the last day.
Mentawai Squirrel (Callosciurus melanogaster). NP. Two sightings only.
Fraternal Squirrel (Sundasciurus fraterculus). PH. Seen almost daily e.g. Sep 10 (iNat post).
Mentawai Long-tailed Giant Rat (Leopoldamys siporanus). PH. Scoped by PC and seen well on Sep 10 @ 2030: iNat post.
Mentawai Rat (Rattus lugens). PH. The rat commonly seen in the palm plantation areas appears to be this species. iNat posts: Sep 8 @ 1915 (two in the open, possibly juveniles?); Sep 11 @ 2051;
C. Reptile List
Black-headed Cat Snake (Boiga nigriceps). iNat post (Sep 8 @ 2018). Image below.
Rough-scaled Sun Skink (Eutropis rugifera). PH. Seen at the village house. iNat post (Sep 8). Image below.
Common Sun Skink (Eutropis multifasciata). PH. Seen on the logging trail, Sep 8 @ 1005.
Dusky Flying Lizard (Draco obscurus). PH. Sep 8 @ 1800. iNat post. Image below.
Asian House Gecko (Hemidactylus frenatus). PH. Seen at the village house.
D. Notable Bird Records
We were not focused on birds but did see the following:
Mentawai Scops Owl (Otus mentawi). PH. We generally saw at least one each night, usually found by Ismael e.g. Sep 9: iNat post.
Sunda Frogmouth (Batrachostomus cornutus). PH. One calling and scoped by PC on Sep 10 @ 1943: iNat post. iNat has no other frogmouth posts for Siberut but there is one post on Sipora. Our guides recognized the call and the bird. Haryoko (2020 p19) stated that their recordings “sound similar to recordings previously made on Siberut that have been putatively identified as Sunda Frogmouth (Demeulemeester, 2009). Museum specimens are needed to clarify the taxonomic status of this population of Batrachostomus“.
Red-legged Crake (Rallina fasciata). PH. One scoped by PC on Sep 10 @ 2010: iNat post. There are no prior iNat records and it is not listed in the Siberut Bird Checklist compiled by Lepage (2024).
Rufous-backed Dwarf Kingfisher (Ceyx rufidorsa). PH.
Blue-eared Kingfisher (Alcedo meninting). PH. iNat post.
E. Trip Data, Site Information and Logistics
SITE AND TRIP INFORMATION
SwaraOwa organization (https://swaraowa.org/). Contact Wawan (Arif Setiawan): wawan5361@gmail.com). SwaraOwa is focused on protecting the gibbons, other primates and their habitat at various locations.
Trip package: our package included +1 hour canoe trips to/from Toloulaggo; homestay at a village house about 60 m from the beach; guided morning and evening walks; the guides staying at the same house, with the host family. At the house we used the two front rooms, using mattresses on the floor with mosquito nets. The family cooked all our meals. There was a side-room with bucket baths and squat toilet. Power from the village generator was on from sunset to sunrise. Cell data reception was sporadic.
Toloulaggo village: There are no cars or wide roads in the village. The main tracks we used were a motorbike track heading northwest past the school and a logging trail heading west from the village with the option of a southern loop. The village had a few small shops selling essentials; one served Bintang. The Toloulaggo school field lat/long is -1.7337 99.2415; I used this with up to 2 km error for my iNat posts.
Malaria prophylaxis: I took doxycycline.
ITINERARY (7-12 Sep 2024)
Day 1: Sat 7
0700-1100: ferry from Padang to Pelabuhan Sikabaluan.
1200-1400: ferry from Pelabuhan Sikabaluan to Pelabuhan Maileppet.
1615-1750: canoe trip from Puro to Toloulaggo.
2000-2230: night-walk.
Day 2: Sun 8
0615-1030: Morning walk on the logging trail behind the village.
1700-2130: Evening walk on the school track.
Day 3: Mon 9
0700-1100: morning walk on a hill trail and back on the school track.
1445-1530: village walk with Franky to look for fruit bats in the palm trees.
1745-2015: night walk.
Day 4: Tue 10
0600-1200? Morning walk on the logging trail and southern loop.
1730-2300: evening walk along school track and forest and field paths to a farm hut (w1451).
Day 5: Wed 11
0700-1000: morning walk on school track and side-trails.
1800-2100: Evening walk on the school track.
Day 6: Thu 12
0750-0900: motor-canoe trip to Puro.
1200-1400: ferry from Pelabuhan Maileppet to Pelabuhan Sikabaluan, then 1435-1815 to Padang.
LOGISTICS
Seasons: the dry season is May-October but we had some heavy rain; the wet season is November-April.
Ferries from Padang to Siberut: Tourist tickets cost 350,000 IDR each way ($25). At the time of writing the ferry operated three times per week, going to both ports on Siberut; only the Thursday ferry goes direct from Padang to the southern port (Pelabuhan Maileppet); the other two go first to the northern port (Pelabuhan Sikabaluan). Tickets with allocated seating includes normal luggage; surfboards are extra. The lower deck main cabin had A/C and about 200 seats set up as 1 aisle with 4 seats each side; the upper deck was open-sided and partly under cover and had some bench seats. At the last row of seats in the cabin a guy sold local coffee and snacks. There was weak cell data reception at the Siberut ports.
Exchange Rate (2024 Sep 4): US$1 – 15,470 IDR; 100,000 IDR = $6.46.
Visas: I did Visa on Arrival at Padang (5th April 2024) for an 8-day visit. I was charged $34.
Power: Indonesia uses Type C and F power plugs. Power supply is 230 V at 50 Hz.
SIM Card: I bought a Telkomsel sim card (bought off the street) but to register my card in Padang I had to go to the “GraPARI Telkomsel padang” office (as shown on google maps). Address: Dalam, Jl. Khatib Sulaiman No.51, RW.04, Lolong Belanti, Kec. Padang Utara, Kota Padang. I had to show my passport; I was in the office for about 30 minutes. I bought a data package of 16 GB for 40,000 IDR, valid for 30 days. More information can be found here (Wild Sumatra sim card info).
Taxis in Padang: I used GRAB for taxi (car and motorbike).
F. References
Lepage D (2024 Aug 3). Checklist of the birds of Siberut. Last modified: 2024-08-03. Avibase. https://avibase.bsc-eoc.org/checklist.jsp?region=IDstba01&list=howardmoore
Eaton JA (2014 July). Observations of Mentawai Palm Civet Paradoxurus (hermaphroditus)
lignicolor from Siberut island, Indonesia. Small Carnivore Conservation 50:61–63.
Haryoko T, Johnson O, Brady L, Shakya SB, Yohanna IM, Ritonga RP, Prawiradilaga DM, Sheldon FH (2020 June). Recent Ornithological Expeditions to Siberut Island, Mt. Talamau and Rimbo Panti Nature Reserve, Sumatra, Indonesia. Treubia 47(1):13–38. DOI: 10.14203/treubia.v47i1.3839
Spence M (2018). Siberut 2018. Report posted on mammalwatching.com.
Wilting A, Sollmann R, Meijaard E, Helgen KM, Fickel J (2012). Mentawai’s endemic, relictual fauna: is it evidence for Pleistocene extinctions on Sumatra? Journal of Biogeography (2012). doi:10.1111/j.1365-2699.2012.02717.x
Whitten JEJ (1981). Ecological separation of three diurnal squirrels in tropical rainforest on Siberut Island, Indonesia. Journal Zoology of London 193(3):405–420. doi:10.1111/j.1469-7998.1981.tb03453.x.
