© Mo Ismael
"Biodiversity hotspots" are Earth’s most biologically rich—yet threatened—terrestrial regions. To qualify as a biodiversity hotspot, an area must meet two strict criteria:
- Contain at least 1,500 species of vascular plants found nowhere else on Earth (known as "endemic" species).
- Have lost at least 70 percent of its original surface area. Many of the biodiversity hotspots exceed the two criteria.
The Eastern Afromontane biodiversity hotspot was first recognized as globally important for species conservation by Mittermeier et al. (2004) when the global hotspot total was raised from 25 to 34 (now 36), following a reappraisal in light of additional data. One of the results of this reappraisal was to divide the original Eastern Arc Mountains and Coastal Forests of Tanzania and Kenya (EACF) hotspot between two newly defined hotspots—the Eastern Afromontane biodiversity hotspot, and the Coastal Forests of Eastern Africa biodiversity hotspot. The Eastern Arc Mountains were thus absorbed into a much larger hotspot, while the Coastal Forests hotspot was expanded to Somalia and Mozambique.
The Eastern Afromontane biodiversity hotspot can roughly be divided in five sub-regions: the Arabian Peninsula, the Ethiopian Highlands, the Albertine Rift, the Eastern Arc Mountains, and the Southern Montane Islands.
The Arabian Peninsula
Biodiversity in the Arabian Peninsula is highly reliant on traditional agricultural practices, such as shade coffee plantation, that create micro-biomes of high biodiversity value for plants, reptiles and birds. The Eastern Afromontane area, in particular the Ibb and Udayn Key Biodiversity Areas, are the most species-rich sites in the whole of the Arabian region.
The Ethiopian Highlands
The Ethiopian Highlands harbor an estimated 5,200 plant species, of which at least 200 are endemic. About 680 species of birds live in these highlands, including about 30 endemics. Six endemic genera of amphibians are found here, as well as nearly 200 mammals, including the endemic Ethiopian wolf (Canis simensis) which is the rarest canid in the world.
The Albertine Rift
The Albertine Rift hosts more than 1,000 bird species. Approximately 400 fish species are endemic to Lake Tanganyika, including a diversity of cichlids and at least 12 large endemic catfishes. The most charismatic mammals of the Albertine Rift, and of the entire hotspot, are the highly endangered gorillas and other primates that try to survive here.
Eastern Arc Mountains
The Eastern Arc Mountains host 3,473 species in 800 genera, of which at least 453 species and around 40 genera are believed to be endemic, including trees, shrubs and herbs. Among the best-known flowering plants of this part of the hotspot are the African violets and the African primroses. Nearly 80 species of butterfly are endemic to the Eastern Arc Mountains.
Southern Montane Islands
The Southern Montane Islands include a range of mountains and ‘inselbergs’ which host a variety of endemic reptiles and amphibians including snakes, chameleons, and frogs - often confined to one single mountain. In between these mountains lies Lake Malawi/Lake Niassa which is home to more than 800 fish species, most of which are endemic.