Current view: Text account
Site description (2001 baseline):
Site location and context
This site is 180 km long and 20–25 km wide, and is located 3 km from Ranohira. It consists of a large sandstone massif, with a peculiar ruinlike aspect, that rises out of a plain. This chain of outcrops includes deeply eroded canyons, the most famous of which are Monkey Canyon and Rat Canyon. The hydrographic network is composed of clear, fast-flowing streams, which drain into the tributaries of the Menamaty in the east, and into those of the Mangoky and Malio in the west. There are also marshes, such as at Andranovorinkaolo, as well as lakes, such as the Golden Lake, whose flora includes
Polygonum,
Echinochloa,
Panicum and
Cyperus. Forest covers 10% of the park’s area, and comprises three types. The dense, dry deciduous forest, mainly composed of
Commiphora and
Dalbergia, is relatively degraded. Gallery forest is dominated by
Eugenia,
Tamarindus and
Mangifera—one area of this type, Andranofotsy, in the north of the park, has an area of c.240 ha. Low- and mid-altitude, dense, humid evergreen forest occurs in the shelter of canyons and is composed of
Voacanga,
Nuxia,
Weinmannia and
Tambourissa. The understorey is composed of thick clumps of ferns
Blechnum. The vegetation on open areas of bare rock includes species of
Pachypodium,
Kalanchoe,
Senecio,
Aloe,
Helichrysum and
Euphorbia. Wooded savanna covers 40% of the site’s area, and includes trees of
Stereospermum,
Albizia,
Borassus,
Pemphis and
Dicoma. Open savanna, with or without scattered palms (of
Bismarckia and
Hyphaene) is more common.
See Box and Tables 2 and 3 for key species. Eighty-one species are known from the site, of which 27 are endemic to Madagascar. The range of
Monticola bensoni is restricted to the Isalo–Zombitse Vohibasia region, including Analavelona (IBA MG066) and possibly the Mangoky canyons (MG063). It appears to have a rather patchy distribution within the park, being absent from large areas in the centre.
Non-bird biodiversity: Lemurs: Mirza coquereli (VU), Propithecus verreauxi verreauxi (VU), Lemur catta (VU).
Pressure/threats to key biodiversity
Uncontrolled bush-fires are the main threat, but others include illegal exploitation for firewood and construction wood, and poaching. Sapphire mining is likely to become a problem in the near future.
Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Parc National d'Isalo (Madagascar). Downloaded from
https://datazone.birdlife.org/site/factsheet/parc-national-disalo-iba-madagascar on 29/12/2024.
