Furcifer balteatus
Distributional expansion of the Malagasy chameleon Furcifer balteatus (Duméril & Bibron, 1851) with new locality records from central and eastern Madagascar
By Petr Nečas
Abstract
Furcifer balteatus is a Malagasy chameleon historically known from two isolated enclaves in the southeastern escarpment. Published distributional data are sparse and discontinuous, and continuity between known sites has remained unresolved. Fieldwork conducted by the author in 2025–2026 confirms both historical enclaves, including the southeastern extreme, and documents four new localities that extend the known range more than 250 km northward and onto the central Malagasy plateau. These records substantially revise the documented distribution of the species.
Key words: Furcifer balteatus; Madagascar; range extension; central plateau; southeastern escarpment; biogeography; conservation.
Introduction
Furcifer balteatus was described by Duméril and Bibron in 1851. The terra typica is Ranomafana in southeastern Madagascar (Glaw 2015). The species is treated in Glaw and Vences' field guide (Glaw & Vences 2007), in the IUCN Red List account (Jemkins & al. 2011), and in standard taxonomic repositories such as the Reptile Database and chameleons.info. All published sources agree that the species is endemic to humid forests of southeastern Madagascar, but the available distributional information is limited and fragmented.
Historical distribution
Published data indicate that Furcifer balteatus occurs in two isolated enclaves. The first lies in the central southeast around Ranomafana and Ifanadiana at approximately 1,050 m (Raselimanana & Rakotomalala 2003; Glaw & Vences 2007). The second lies in the extreme southeast, with records from Manongotry at 800 m and Tsitongambarika, and additional records below 800 m. The IUCN account (Jenkins & al. 2011) estimates the combined extent of occurrence at 1,971 km² but explicitly states that continuity between these areas is unknown and that the species may be restricted to smaller portions of the documented sites. This work also giver the lower elevation limit at 0m a.s.l. without any explanation and probably erroneously, and the upper limit at 1050m a.s.l.
Confirmation of historical enclaves
Fieldwork by the author in 2025–2026 confirmed the persistence of both historical enclaves. The central‑eastern enclave extends from Ranomafana National Park through Ifanadiana and southwards to Fort‑Carnot: 21°52'S, 47°26'E; 510m a.s.l.
The southeastern enclave, including Manongotry and Tsitongambarika, was also confirmed.
New locality records
Four new sites documented by the author extend the known range more than 250 km northward and demonstrate occurrence outside the eastern escarpment, onto the central plateau.
1. Longozabe, south of Anosy Anala
Three specimens.
Coordinates: 19°30'S, 48°07'E
Altitude: 667m a.s.l.
2. Ampasamadinika, southwest of Anosy Anala
Two specimens.
Coordinates: 19°30'S, 48°08'E
Altitude: 606m a.s.l.
3. Near Ambatolaona Ouest, north of Mandraka
One specimen.
Coordinates: 18°53'S, 47°51'E
Altitude:1402m a.s.l.
4. Near Ambodiampaly, central highlands east of Antananarivo
Seven specimens.
Coordinates: 18°47'49''S, 46°45'40''E
Altitude: 1131m a.s.l.
Biogeographic significance
The new records demonstrate that Furcifer balteatus is not restricted to the southeastern escarpment. The Ambatolaona Ouest and Ambodiampaly sites show occurrence on the central plateau, a region not previously documented for this species. The Longozabe and Ampasamadinika sites lie between the historical enclaves but do not resolve continuity. The northward extension of more than 250 km substantially revises the known range and indicates that the species occupies a broader set of forest habitats than previously recorded.
Altitudinal span
Based on the observations and data, Furcifer balteatus typically inhabits forested ares or plantations with trees at middle elevations, with the total altitudinal span between 551m and 1402m a.s.l.
Reasons for scarcity of data
The scarcity of published distributional data for Furcifer balteatus likely reflects several factors noted in the literature. The species inhabits humid forest with dense canopy, making detection difficult (Glaw & Vences 2007). Surveys in southeastern Madagascar have historically been limited in spatial coverage, and many forest blocks remain poorly sampled duen to inaccessibnility or hard accessability. The species appears to occur at low densities, and its cryptic behaviour further reduces detectability. The IUCN account notes uncertainty about continuity between known sites, indicating that large areas of potential habitat have not been systematically surveyed. These combined factors have resulted in a fragmented and incomplete distributional record.
Conservation considerations
The new records expand the documented extent of occurrence beyond previously published values. Habitat condition at the new sites must be assessed to determine conservation relevance. Given ongoing habitat loss in eastern and central Madagascar, the newly documented populations may represent important conservation units.
References
Duméril, A.M.C. & Bibron, G. 1851. Erpétologie générale ou histoire naturelle complète des reptiles. Tome 7. Paris: Roret. pp. 1–781.
Glaw, F. & Vences, M. 2007. A Field Guide to the Amphibians and Reptiles of Madagascar. Cologne: Vences & Glaw Verlag. 496pp.
Glaw, F. 2015. Taxonomic checklist of chameleons (Squamata: Chamaeleonidae). Vertebrate Zoology 65(2): 167–246.
Jenkins, R.K.B., Andreone, F., Andriamazava, A., Anjeriniaina, M., Brady, L., Glaw, F., Griffiths, R.A., Rabibisoa, N., Rakotomalala, D., Randrianantoandro, J.C., Randrianiriana, J., Randrianizahana, H., Ratsoavina, F., Raxworthy, C.J. & Robsomanitrandrasana, E. 2020. Furcifer balteatus (amended version of 2011 assessment). The IUCN Red List of Threatened Species 2020: e.T172934A176384350. https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T172934A176384350.en. Accessed 28 July 2026.
Nečas, P. chameleons.info. Species account for Furcifer balteatus. (Online species account)
Raselimanana, A.P. & Rakotomalala, D. 2003. Herpetofauna of southeastern Madagascar. In: Goodman, S.M. & Benstead, J.P. (eds.), The Natural History of Madagascar. Chicago: University of Chicago Press. pp. 951–969.
Uetz, P., Freed, P. & Hošek, J. (eds.). The Reptile Database. Species entry for Furcifer balteatus. (Online database)
