|Central coordinates||48o 36.00' East 12o 54.00' South|
|IBA criteria||A1, A3|
|Altitude||0 - 206m|
|Year of IBA assessment||2001|
Site description The site is located 50 km north-east of Nosy Be and 30 km off the western Malagasy coast. Nosy Mitsio, located in the centre of the archipelago, is the largest island, being c.12 km long and up to 3 km wide. One peak rises to 206 m in the northern area and another rises to 130 m in the centre. Surrounding islets include, in the north, Nosy Ankarea and Nosy Lava, and in the south, Nosy Antaly, Nosy Tsitampevina, Nosy Tsarabanjina, Nosy Toloho, and the ‘Quatre Frères’ islets. The Quatre Frères (Nosy Beangovo, Nosy Betalinjona, Nosy Antsoha and Nosy Betanihazo) are rocky contiguous domes, respectively 63 m, 76 m, 51 m and 88 m high. They are partly covered by savanna, especially on the summits. Nosy Lava is an elongated reef, 3.5 km long and 1.5 km wide, and covered by vegetation. It rises to 160 m. A beach, which floods at high tide, stretches along the northern part of this island. Nosy Toloho is covered by dense dry forest (up to 12–14 m high).
Key Biodiversity See Box and Table 3 for key species. Ten species are known from the site, of which one is endemic to Madagascar. The site is home to three breeding pairs of Haliaeetus vociferoides (on the Quatre Frères, Nosy Toloho and Nosy Lava). The Quatre Frères are also home to colonies of Fregata ariel and F. minor—the only site known in Madagascar where Fregata species breed—including c.50–100 pairs nesting on one of the islets. Some five pairs of Phaethon lepturus and 300–500 breeding individuals of Sula leucogaster have also been observed—the latter species has increased significantly since the 1970s. A pair of Falco peregrinus has been recorded on one of the islands.
Non-bird biodiversity: Sirenian: Dugong dugon (VU).
|Species||Season||Period||Population estimate||Quality of estimate||IBA Criteria||IUCN Category|
|Madagascar Fish-eagle Haliaeetus vociferoides||resident||1997||3 breeding pairs||-||A1, A3||Critically Endangered|
|Land-use||Extent (% of site)|
References Langrand (1987), Polunin (1979), Rabarisoa et al. (1995), Watson et al. (1993).
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Recommended citation BirdLife International (2015) Important Bird and Biodiversity Area factsheet: Mitsio archipelago. Downloaded from http://www.birdlife.org on 29/11/2015
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