Biodiversity Hotspot- Madagascar & the Indian Ocean Islands

1. Biodiversity Hotspot-Madagascar & the Indian Ocean Islands 

2. What is a Biodiversity Hotspot? According to Conservation International, a biodiversity hotspot is defined by the following 2criteria: • It must have at least 1,500 species of endemic vascular plants Endemism is the degree to which species are found only in a given place. 2. must have lost at least 70% of its original area. 34 hotspots have been identified worldwide

3. Our research is based on-Madagascar & the Indian Ocean Islands Hotspot Region: Madagascar, Seychelles (including Aldabra), the Comoros, Mauritius (including Rodrigues), and the French overseas departments of Réunion. • Seychelles, Comoros &Mascarene islands in the Indian Ocean have many critically endangered bird species. • Seychelles are also home to the only endemic family of amphibians: the Sooglossidae, and the Aldabra giant tortoise

4. Madagascar & the Indian Ocean Islands Hotspot Menu • Unique Biodiversity & Endemism • Hotspot Plant species • Hotspot Vertebrate species- a) Birds b) Mammals c) Fishes d) Reptiles & Amphibians • Hotspot Invertebrate species

5. 1.Unique Biodiversity & Endemism • Flora and fauna diversity extremely diverse & endemic. • resulted from tens of millions of years of isolation from the African mainland and from people, who didn't arrive until 2,000 years ago. • Endemism is marked not only at the species level, but also at higher taxonomic levels. • 8 plant, 4 bird, and 5 primate families are endemic. • 70% of Madagascar’s species are endemic. Back to Menu

6. 2.Hotspot Plant species More than 13,000 species of vascular plants, 90 % endemic At least 310 endemic genera of plants. Local endemism is high as well; some individual mountaintops have 150 to 200 endemic plants. • Madagascar's signature endemic plant, traveler's tree • 6 out of 8 species of the baobab, or bottle tree found in drier regions of the west and south Madagascar. bottle shaped trunks store large reserves of water(adaptation) Back to menu

7. 3a.Hotspot Vertebrates- Birds Birds of Madagascar –low diversity but spectacular endemism. More than 300 bird species,60% endemic. Over 55 endemic species are currently threatened, and 32 have already gone extinct, mainly from the Mascarenes. Birds of the Indian Ocean islands- 10 bird species extinct in Réunion since 1500 & all the endemic birds of Mauritius are threatened. Back to Menu

8. 3b.Hotspot Vertebrates- Mammals Mammals in Madagascar • Low diversity, 90% endemic • more than 150 mammal species. • Lemurs are unique to Madagascar. represented by 5families of primates. 72 kinds of lemurs (species and subspecies), representing 15 genera highest primate endemism in the world. • One of the most unusual lemur species is the aye-aye • more than 15 endemic bat species, including the Madagascar flying fox and numerous endemic rodents, like the unusual giant jumping rat • primary predator of lemursis the carnivore fossa • The endemic tenrecs, a unique family of insect-eating mammals, occupy the ecological niche that shrews and moles occupy elsewhere.

9. 3b.Hotspot Vertebrates- Mammals (contd) Mammals are thinly distributed elsewhere on the Indian Ocean Islands, but include the world's largest bat, Livingstone's flying fox (Pteropuslivingstonii, CR) on the Comoros. Back to menu

10. 3c.Hotspot Vertebrates- Fishes • smaller islands are dominated by species with wide marine distributions, which enter both brackish and freshwater habitats. • Madagascar's fish are mainly freshwater species of continental origin that have evolved on the island. nearly 100 endemic species of fish. Back to menu

11. 3d.Hotspot Vertebrates- Reptiles & Amphibians Reptiles-one endemic reptile family but high species diversity and endemism 96% of nearly 400 reptile species are endemic. chameleon diversity- proposed that all the worlds' chameleons originated here. • endemic reptile in the Indian Ocean islands is the Seychelles' Aldabra giant tortoise . it is considered threatened by development, illegal trade, and natural disasters. Amphibians- 2 endemic families of amphibians: • Sooglossidae, found in the Seychelles • Mantellidae, endemic to Madagascar and Mayotte. Among the flagship amphibians are the beautiful frogs of the genera Mantella and Scaphiophryne and the tomato frog , a bright red, bullfrog-sized animal found only in a small corner of northeastern Madagascar. Back to menu

12. Hotspot Invertebrate fauna Madagascar: 5,800 species, 86% are endemic Some examples: terrestrial snails, dragonflies, tiger beetles, scarab beetles, true butterflies ,freshwater crayfish and freshwater shrimp. Seychelles: estimated 5,100 species,80% are endemic • unique and amazing invertebrate flagship species is the endemic giant tenebrionidbeetle, restricted to 1small island in the Seychelles, and one of the largest terrestrial invertebrates in the world. • largest millipede and populations of the world's largest terrestrial invertebrate, the coconut or robber

13. Hotspot- Food web & Food chain

14. Key species in this hotspot and their relationships with other species- • Madagascar's signature endemic plant, the traveler's tree is pollinated by the island's flagship vertebrate species, the lemurs. • Grandidier's baobab, the largest baobab species, is pollinated by nocturnal lemurs. It is the most heavily exploited tree with the fruit, seeds, wood and bark all being collected and used by local people for making rope and medicines. The greatest threat to this tree comes from the transformation of its habitat into agricultural land but it is also threatened by fire, overgrazing and bark collection. • Other Malagasy species are pollinated by fruit-eating bats.

15. Role of abiotic factors in the Hotspot • Soil- is very moist, which allows many plants to grow and prosper there. • Sunlight-lot of sunlight because of the large quantities of tall trees. These trees absorb all of the sunlight, which has caused the plants to adapt to this. • Rainfall- abundant in the lowland rainforests, plants & animals adapted to it. • Climate- of a lowland rainforest is hot and humid. If the climate gets any colder and dryer, many of the plants & animals would not be able to survive.

16. Human Impact on the Hotspot • Demands from todays global markets threaten the diversity brought about by the isolation that the island of Madagascar has experienced. • Deforestation, unsustainable agriculture and erosion fueled by human population growth all endanger the islands unique habitats. • The result: several species such as lemurs and chameleons that evolved over millions of years may become extinct before the end of the century.

17. References • http://www.eoearth.org/article/Biological_diversity_in_Madagascar_and_the_Indian_Ocean_Islands • http://www.conservation.org/WHERE/PRIORITY_AREAS/HOTSPOTS/Pages/hotspots_main.aspx • http://www.environment.gov.au/biodiversity/hotspots/index.html