SUMMARY: At Kiwengwa Caves (4-5 Nov 2024) I saw four bat genera with not all confirmed to species level. These were Angolan Soft-furred Fruit Bat, Decken’s Horseshoe Bat (probable identification), Least Long-fingered Bat (tentative identification) and a Slit-faced Bat species.
By Paul Carter (paulcarter@pacapix.com)
Posted 28 Sep 2026
See my Zanzibar home page for links to other site reports and logistics.
Contents
a) Introduction
b) Mammal records
c) Reptile records
d) Site information
e) References
Appendix 1: Comments on Rhinolophus species reported on Zanzibar
Appendix 2: Comments (2024) by Michal Sloviak on Rhinolophus at Kiwengwa Caves
Abbreviations: iNat – iNaturalist. HMW – Handbook of the Mammals of the World. ACR – African Chiroptera Report, MDD – mammal Diversity Database.
A. Introduction
There appears to be no published research on the bats of Kiwengwa caves. Stanley (2007), Field Museum of Natural History Chicago, noted in a two-page summary that research had been done at Kiwengwa Caves during 2005-2007, but there appears to be no follow-up publication.
Kurrent Technologies (2024) in their regional survey stated that “Based on vouchers from various museum collections, the African Chiroptera Report (2022) identified 32 species of bats from 10 separate families as occurring on Unguja Island (Table 4-1). Rhinolophus lobatus – identified during the baseline sample and not previously recorded brings the overall number of bat species on Unguja Island is now reported to be 33. The actual number of species reported on the island may be an overcount due to changes in taxonomy (naming), where some of the species’ names may refer to the same species or vice versa”.
Miniopterus: Stanley (2007), at Kiwengwa Caves, mentioned the first known occurrence of Miniopterus minor from Unguja. Table 4.1 in Kurrent Technolgies (2024) lists Least Long-fingered Bat (Miniopterus minor) as the only Miniopterus species on Unguja. However, iNat range maps (2024) indicate that African Long-fingered Bat (Miniopterus africanus) is present on Zanzibar. Greater Long-fingered Bat (Miniopterus inflatus) is not in range but known near Mombasa. Other records on iNat are only shown as Miniopterus sp.
Nycteris: MDD lists 7 Nycteris species in Tanzania; iNat (2024) shows the following occur on Zanzibar: Egyptian Slit-faced Bat (Nycteris thebaica), Large Slit-faced Bat (Nycteris grandis), and Hairy Slit-faced Bat (Nycteris hispida). Kurrent Technologies report (2024 Table 4.1) lists those three as well as Large-eared Slit-faced Bat (Nycteris macrotis).
Rhinolophus: Kurrent Technolgies (2024 Table 4.1) listed five Rhinolophus species but during their survey they only trapped and recorded two species (R. deckenii and lobatus). In Appendix 1 (this post) I summarise that there appears to be six Rhinolophus species present on Zanzibar islands: acrotis (clivosus), deckenii, fumigatus, lobatus, simulator and swinnyi (rhodesiae).
This report will be updated if further information on the Rhinolophus species at Kiwengwa Cave becomes available. Please email me on any errors noted. I would also be interested to know if anyone else thought there were two size forms/populations of Rhinolophus.
B. Mammal Records
I photographed four bat genera in the North Cave and South Cave at Kiwengwa Caves.
1) Angolan Soft-furred Fruit Bat (Myonycteris angolensis)
Seen only at Kiwengwa North Cave (5/11-0923h). One of the group was seen with a pup.
2) Horseshoe Bats (Rhinolophus)
During my visit I thought there were two size populations of Rhinolophus (at both South and North Cave), possibly representing two species. They have similar nose-leaf structure. On my photo record notes I referred to the larger and smaller forms as L and S. What I refer to as R. deckenii below were only those that I noted as L (except one that did not have a size remark).
2a) Decken’s Horseshoe Bat (Rhinolophus deckenii)
Tentative ID – see Appendix 2. Seen at both South and North Cave.
The connecting process (CP) is squarish to rectangular in shape, rising straight up from the sella, and with a rounded tip, is hairy and intersects the sella below the tip of the sella. The two images below of a bat on 4 Nov 1713h showed the lower lip has three mental grooves (so not R. fumigatus); it has mid-brown upperparts, and lighter brown below.
2b) Rhinolophus sp. (5 Nov 0956h). One image below but multiple images at iNat HERE. The lower lip has 1 distinct central groove, possibly one each side of that.
2c) Rhinolophus sp. (4 Nov 1722h), at Kiwengwa South Cave (4/11). Multiple images posted at iNat HERE. I had not noted whether this was one of the smaller or larger forms. It seems to have a different shaped connecting process compared to what is shown above as R. deckenii. Images seem to show that the CP projects forward a little, whereas the deckenii images seem to show that the CP rises up vertically from the sella and not projecting forward. Ventral fur is a silvery/greyish brown (like 2d and 2e below, both small forms).
2d) Rhinolophus sp. (small form, 5 Nov 0952h). Posted at iNat HERE. It has a high and rounded connecting process. Compare to Fig 143 in Monadjem et al (2020, p275).
2e) Rhinolophus sp. (small form, 4 Nov 1708h). Posted on iNat HERE. One of the small form Rhinolophus, same pelage and nose-leaf as that shown above. It has a high and rounded connecting process.
3) Slit-faced Bat sp (Nycteris sp.)
Seen only at North Cave (5 Nov 0922h). See iNat post HERE.
4) Least Long-fingered Bat (Miniopterus minor)
Seen at South Cave (4/11 + 5/11). Tentative ID is based on Stanley (2007), and the Kurrent Technologies report (2024, incl. Table 4.1) which indicates that only one species of Miniopterus is present on Zanzibar.
5) Black-and-rufous Sengi (Rhynchocyon petersi).
Photographed at 10.45 AM Nov 5 on the road leaving the caves.
OTHER
At nearby Pongwe we also saw two mammal species:
a) Wahlberg’s Epauletted Fruit Bat (Epomophorus wahlbergi), iNat post HERE.
b) Small-eared Greater Galago (Otolemur garnettii), iNat post HERE.
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C. Reptile Records
Spotted Green Snake (Philothamnus punctatus). No photo. Seen near Kiwengwa town area (4/11/2024), crossing the road; green, slim, about 4 foot long.
D. Site Information (2024)
To visit these caves, you need to be accompanied by one of the guards. The guard that accompanied me did not know the names of any of the species seen. The caves are very close to the office where you park. It was not possible to do a night walk in the area. I visited both North Cave and South Cave; they are about 200 m long. The East Cave is not open to tourists.
Pongwe, on the coast, is about 7 km by car to the caves. We stayed at Pongwe Bay Resort. It has Wahlberg’s Epauletted Fruit Bat (Epomophorus wahlbergi) day-roosting in thatched rooves, and Small-eared Greater Galago (Otolemur garnettii). Santa Maria Coral Park, the beach restaurant south of Pongwe Bay Resort, has habituated Small-eared Greater Galago that the staff called in; they appeared after a few minutes of calling, for mango hand-outs.
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E. References
- ACR (2025): AfricanBats NPC (2025). African Chiroptera Report 2025. Van Cakenberghe, V. and Seamark, E.C.J. (Managing Editors). Online: 17 Dec 2025. Facebook LINK.
- Rhinolophus acrotis – p306.
- Rhinolophus deckenii – p336.
- Rhinolophus fumigatus – p356.
- Rhinolophus lobatus – p377.
- Rhinolophus simulator – p394 (includes Rhinolophus rhodesiae).
- Rhinolophus swinnyi – p401. Occurs on Unguja. Range map Fig 124.
- HMW9: Wilson DE, Mittermeier RA (Eds) (2019). Handbook of the Mammals of the World v9: Bats. Lynx Editions, Barcelona.
- Rhinolophus clivosus – p296, FA 42-59. MDD-2/4 notes that forms of “Rhinolophus clivosus” in the Afro-tropics from Ethiopia south to South Africa are now “Rhinolophus acrotis”.
- Rhinolophus deckenii – p293. FA 48-56 mm.
- Rhinolophus fumigatus – p290. FA 47-60 mm.
- Rhinolophus lobatus – p283. FA 43-50 mm.
- Rhinolophus simulator – p286. FA 42-49 mm.
- Rhinolophus swinnyi – p284. FA 40-45 mm.
- Kurrent Technologies (2024 May 28). Provision of Consultancy Service for Conducting Birds and Bats Study along the Proposed 132 kV Backbone Transmission Line Route in Unguja. Final Report: Bat impact study. Zanzibar Energy Sector Transformation and Access Project (ZESTA). Consultancy contract TZ‑ZECO‑253715‑CS‑QCBS.104 pp. https://documents1.worldbank.org/curated/en/099052824111036693/pdf/P1695611b9d2090a18e111b266a10ec142.pdf
- See Section 4.1 “Bat species recorded on the island”.
- MDD-2/4 – Mammal Diversity Database (2026 Jan 02). Mammal Diversity Database (v2.4) [Data set]. Zenodo. https://zenodo.org/records/18135819 .
- Monadjem et al (2020): Monadjem A, Taylor PJ, Cotterill F, Schoeman MC (2020 June). Bats of Southern and Central Africa: A biogeographic and taxonomic synthesis, 2nd edition. pp640. Wits University Press. https://doi.org/10.18772/22020085829.
- Rhinolophus clivosus – p216. CP (connecting process) is “high and rounded”. (Note that ACR (2025 p306) treat this as R. acrotis augur).
- Rhinolophus deckenii – p234. Medium-small bat (around 15 g). CP is “low and rounded” (Fig 118, p236, in Monadjem et al, 2020). Upperparts “dark brown”; underparts “lighter”. Wings “dark brown”. Lower lip has “deep, central mental groove, between two superficial grooves”.
- Rhinolophus fumigatus – p246. Medium sized (around 14 g). Upperparts “grey-brown”; underparts “light grey”. Lower lip has “one mental groove”.
- Rhinolophus lobatus – p254. A small (around 8g). CP is “high-rising, pointed”.
- Rhinolophus rhodesiae – p272. Very small (around 5.7 g), CP is “characteristically high and rounded”.
- Rhinolophus simulator – p280. A small bat (around 9 g). CP is “rounded”. Upperparts “light to reddish-brown”, underparts “much paler fawn”
- Rhinolophus swinnyi – p293. A small bat (around 7 g); endemic to South Africa. But ACR (2025) now shows range extends up to northern coastal Tanzania.
- Stanley WT (2007). Survey of Microchiropteran Bats of Mafia, Pemba and Unguja and Subsequent Creation of Innovative Educational, Scientific and Conservation Tools.Final Report to the Critical Ecosystem Partnership Fund (CEPF Grant #12308). Field Museum of Natural History, Chicago. 22 pp. https://d29l0tur8ol1gj.cloudfront.net/sites/default/files/final_fieldmuseum_surveybats.pdf
- Webala, P (2014). iNat post – Rhinolophus deckenii. https://www.inaturalist.org/observations/569342
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Appendix 1: Comments on Rhinolophus species reported on Zanzibar
Kurrent Technologies (2024) list five Rhinolophus species on Zanzibar: R. deckenii, fumigatus, lobatus, rhodesiae and simulator. ACR distribution tables confirm R. clivosus for Zanzibar, noting that ACR (2025) treats clivosus here as R. acrotis.
MDD-1/12 included R. rhodesiae under R. simulator, but ACR (2025) and Monadjem et al (2020) included under R. swinnyi
In summary I understand the following 6 Rhinolophus species occur in Zanzibar:
R. lobatus: has a pointed connecting process (Monadjem et al, 2020 p254).
R. fumigatus: around 14g, has a low, rounded CP, and one lower lip mental groove (Monadjem et al, 2020 p246).
R. deckenii: around 15g, pelage dark brown on upper parts and lighter on the underparts, it has a rounded CP, lower lip has one deep central mental groove between two superficial grooves; the CP is low and rounded in deckenii (but it looks high in Fig 118, p236), but high and rounded in clivosus (Monadjem et al, 2020 p234).
R. acrotis – previously R. clivosus: around 17g, has one distinct mental groove on lower lip, and a high, rounded CP (Monadjem et al, 2020 p216).
R. simulator: Monadjem et al (2020 p280) note that simulator is a small bat (around 9 g) with a high and rounded CP; lower lip has three mental grooves. MDD-1/12 includes R. gorongosae and R. rhodesiae under R. simulator, but Monadjem et al (2020 p280) noted that the R. swinnyi complex included R. gorongosae and R. rhodesiae. Monadjem et al (2020 p272) note that R. rhodesiae is very small (around 5.7 g). ACR (2025 p395) note “R. gorongosae and R. rhodesiae are no longer recognized as a valid species by Simmons and Cirranello (2023b)”.
R. swinnyi: Monadjem et al (2020 p293) note that R. swinnyi is endemic to South Africa. Monadjem et al (2020 p272) noted R. rhodesiae is near endemic to Southern Africa and that Tanzania records are R. swinnyi or an unidentified species.
References to R. swinnyi in Zanzibar (e.g. the 2024 Wikipedia country list for mammals) seemingly refer to past R. rhodesiae records
Appendix 2: Comments (2024) by Michal Sloviak on Rhinolophus at Kiwengwa Caves
As commented at the iNat post https://www.inaturalist.org/observations/231186951
“It seems that only R. deckenii has been repeatedly confirmed from the cave systems of Unguja Island. There are several clues pointing to this, and I have come across this information repeatedly among the local well-founded people of the Jozani-Chwaka Bay Park Authority. The presence of R.swinnyi is mentioned oficially only by Pakenham (1984), while it is not clear which “Zanzibar” it is. Pemba/Unguja ? Periodically every 2-3 years, people from Dar Salaam University do chiropterological research for Zanzibar authorities. Sometime before 2010, a chiropterological survey of the island was also carried out through the Field Museum of Natural History, Chicago. Unfortunately, no publications or information that would be published are available from these researches. According to what we found in the field in 2008 and now in June, I can confirm from my observations the occurrence of bats of the genus Rhinolophus in the eastern part of the island (Kuumbi Cave, Machaga Cave, and Mchekeni Caves in Kiwengwa-Pongwe Forest) and in the northwest in Tazari Cave. There are about 12 other caves that are not open to the public, and they are located in the territory of Jozani Forest. From these caves, rangers (focused on mammals) confirmed only R. deckenii present, base their information again on Dar Salaam University research. Of course, without public datas from captures and specific measurements, they cannot never really confirm if it is R. deckenii. So I think it would be very reasonable to finally do a proper chiropterological research of the entire island of Unguja, and properly publish the results”.
PC (28 Sep 2026): An online check for any research by the Field Museum of Natural History, Chicago, produced only the two-page report by Stanley (2007).
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