East Coast Mountains (45499)
Mauritius, Africa

Site overview

KBA status: confirmed

Global KBA criteria: A1a, B1, B2

Year of last assessment: 2025

National site name: Montagnes de l'Est

Central coordinates: Latitude: -20.3114, Longitude: 57.7019

System: terrestrial, freshwater, subterranean

Elevation (m): 60 to 560

Area of KBA (km²): 97.03791

KBA classification: Global

Legacy site: Yes

Site details

Site description: This KBA is a mountainous region that rises to about 560 meters above sea level. It is located in the South East of Mauritius and include mountains such as Villars, Bambou, Camizard, Lion Mountain, des Creoles, Brise (ou Fendu), Piton Rouge, Table a Perrot, and valleys such as Ferney, Anse Jonchee, Vallee de l'Est, Le Vallon, Le Val, Osterlog, Mont Lagrave, Chat et la Souris, Montagne Blanche, Mont Fayence amongst others. The area receives relatively high rainfall due to orographic factors, since the mountains intercept the South East Trade Winds. The area includes State Lands, and private lands, including 'Mountain Reserves'. Conservation programmes have been initiated in some of the areas, such as Ferney Valley, Kestrel Valley and Vallee de l'Est (all private) and at Mon Brise (Forestry Service, Government) and Osterlog Valley (a government trust). The KBA is characterized by dense forests, rugged terrain, and steep slopes. The area features a mix of sub-tropical vegetation, including native forests, making it an important ecological site. It plays a critical role in the island's conservation efforts by helping to preserve habitats for endemic species, many of which are highly threatened due to the island's history of deforestation, invasive species, and human development. Efforts to protect the area focus on habitat restoration, species monitoring, and controlling invasive species that threaten the local flora and fauna.

Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance because it meets one or more previously established criteria and thresholds for identifying sites of biodiversity importance (including Important Bird and Biodiversity Areas, Alliance for Zero Extinction sites, and Key Biodiversity Areas). KBA identified in the CEPF Ecosystem Profile of the Madagascar and Indian Ocean Islands Hotspot (2014, maintained in 2023). Two species trigger KBA status with three criteria, including A1a, B1 and B2. Mauritius kestrel (Falco punctatus), an En Danger and geographically restricted species triggers A1a, B1 and B2. Mascarene swiftlet (Aerodramus francicus), also geographically restricted, meets B2.

Additional biodiversity: MOLLUSCA: Caldwellia angularis; Dancea semifusca; Gonidomus concamerata; Gonospira modiola; Gonospira producta; Harmogenanina semicerina; Microstrophia clavulata; Omphalotropis clavula; Pachystyla bicolor; Plicadomus sulcatus; PLANTAE: Bertiera zaluziana; Coptosperma cymosa; Eugenia bojeri; Pandanus iceryi; Pandanus macrostigma; Pyrostria fasciculata; Pyrostria macrophylla; Pyrostria viburnoides; Syzygium dupontii. AVES: Falco punctatus; Alexandrinus eques; Nesoenas mayeri; Hypsipetes olivaceus; Coracina typica; Terpsiphone bourbonnensis desolata; Aerodramus francica. MAMMALIA: Pteropus niger; Mormopterus acetabulosus. Cynanchum staubii has been delisted from the KBA since it is restricted to an offshore island in south east of Mauritius, Ile aux Aigrettes.

Manageability of the site: Most of the area is privately owned. A proportion of the area is State Lands leased to private sector for deer (Rusa timorensis) ranching and hunting, and 'gardiennage' (wardening). The rest are unleased State Lands. Some of the area is declared as 'Mountain Reserve' and even when privately owned, the Forestry Service has an oversight ('droit de regard'). Mauritius is one of the most degraded islands in the world, and wherever forests, especially native/endemic, is vital for biodiversity conservation. Conservation is happening on some of the privately owned lands (e.g. Ferney Valley, Kestrel Valley, Vallee de l'Est), as well as conservation on several private hunting lands and some Forestry Service Mountain Reserves (eg Mont Brise). The Mauritian Wildlife Foundation is also active in the KBA (Mauritius Kestrel, Pink Pigeons, Mauritius Cuckoo-shrike, Mauritius Paradise Flycatchers, rare plants, training). Whilst there is some collaboration between the various partners, more is required for the sound management of the area.

Supersedes another site: This KBA superseds East coast mountains (6651) and the two KBAs are merged as they overlap. Their ecosystems are contiguous, with shared biodiversity and bird territories that overlap as well, justifying a merging, from biodiversity conservation and management perspectives.

Delineation rationale: This delineation of this KBA is based on the CEPF Ecosystems Profile revised in 2023 (https://www.cepf.net/sites/default/files/madagascar-and-indian-ocean-islands-ecosystem-profile-brochure-fr.pdf). This KBA includes and replaces the East coast mountains (6651). It covers some of the remaining forest block on the Bambou Mountains and East coast, both privately or State-owned. The Bambou Mountains KBA was based on remaining contiguous forest and biodiversity that the area supported. Thus, the new merged KBA is enclosed by the outermost limits of the combined KBAs, East Coast Mountains (6651) and Bambou Mountains KBA (45499).

Habitats

Summary of habitats in KBA: The habitat is composed of sub-tropical moist forest (though invaded by introduced plants and animals), secondary forests, some plantations, and agricultural (mainly sugar cane, but also vegetable) fields. Some of the area has been converted to pasture for deer.

Land use: Forest (including Mountain Reserves), deer ranching, agriculture (sugar cane, vegetables), abandoned sugar cane lands, high-end housing, (eco)tourism, ecosystems restoration

IUCN Habitat	Coverage %	Habitat detail
Forest		Forest – Subtropical/tropical moist montane
Artificial - Terrestrial		Pastureland
Introduced Vegetation

Threats

Summary of threats to biodiversity at KBA: The region has undergone significant habitat destruction, invasion by introduced species, and development pressure (including proposals for a highway, which have been averted), but still maintains globally threatened endemic plants and animals. Invasive species: Non-native species, such as rats (Rattus spp.), Indian Lesser Mongoose (Urva auropunctatus), feral cats (Felis sp.), Long-tailed Macaques (Macaca fascicularis) and invasive plants (such as Ravenala madagascariensis, Cinnamomum verum, Flacourtia jangomas, Litsea spp., Syzygium jamrosa), pose a significant threat to native wildlife and plants. Habitat loss: Agricultural expansion, urban development, road construction, and deforestation and habitat degradation have led to a reduction in natural habitats across Mauritius, and also at Bambou Mountains. Climate change: Shifts in weather patterns, rising temperatures, and altered rainfall can further stress the biodiversity in the area.

Threat level 1	Threat level 2	Threat level 3	Timing
Residential & commercial development	Housing & urban areas		Ongoing
Agriculture & aquaculture	Annual & perennial non-timber crops	Agro-industry farming	Ongoing
Agriculture & aquaculture	Livestock farming & ranching	Agro-industry grazing, ranching or farming	Ongoing
Human intrusions & disturbance	Work & other activities		Ongoing
Natural system modifications	Other ecosystem modifications		Ongoing
Invasive & other problematic species, genes & diseases	Invasive non-native/alien species/diseases	Unspecified species	Ongoing
Climate change & severe weather	Storms & flooding		Ongoing

Additional information

References: Nicoll M, Jones C G, Groombridge J, Henshaw S, Ruhomaun K, Tatayah V, Zuel N & Norris K (published online 2021). Contrasting recovery trajectories of four reintroduced populations of the Endangered Mauritius Kestrel (Falco punctatus). Ibis. http://doi.org/10.1111/ibi.12987 Taylor J, Norris K, Nicoll M A C, Black E, Vidale P L, Dunning C M, Tatayah V and Jones C G (2021). Evidence of adaptive phenological plasticity to climate warming in an insular tropical bird recovering from near-extinction. (Short title: Adaptive phenology in a recovering tropical island bird). Communications Biology. 164 (41) Cartwright S, Nicoll M, Jones C, Tatayah V and Norris K (2014). Anthropogenic natal environmental effects on life histories in a wild bird population. Current Biology 24 (5). Cartwright S J, Nicoll M A C, Jones C J, Tatayah V and Norris K (2014). Agriculture modifies the seasonal decline of breeding success in a tropical wild bird population. Journal of Applied Ecology 51 (5). doi: 10.1111/1365-2664.12310. Nicoll M, Arlt D, Burgess M, Cartwright S, Jones C, Nevoux M, Senapathi D, Tatayah V and Norris K (2014). Population dynamics and demographic processes in a reintroduced population of the Mauritius Kestrel Falco punctatus. Proceedings: Avian demography in a changing world. British Ornithological Union. http://www.bou.org.uk/bouproc--‐net/avian--‐demography/nicoll--‐et--‐al.pdf.