The islands in the ecoregion are part of Wallacea, a group of indonesian islands which lie between the Australian and Asian continents but were never part of either continent.[5]
The Outer Banda Arc is made up of oceanic sediments, principally coralline limestone, together with some older metamorphic rocks which accreted as the Australian platesubducts under the Banda Sea plate. The Outer Banda Arc includes the Kai Islands, Tanimbar Islands, Babar Islands, and Leti Islands. Yamdena in the Tanimbar Islands is the largest island in the ecoregion. Yamdena is mostly low, with a maximum elevation of 120 meters. Yamdena and several other Outer Arc islands have areas of karst where the island's limestone was uplifted and then eroded.[7]
Climate
The ecoregion has a tropical monsoon climate, with two seasons. The west monsoon season runs from mid-December to June, and brings humidity and higher rainfall. The east monsoon season brings drier weather. On Yamdena, the largest island in the Tanimbar Islands and in the ecoregion, the highest rainfall month is February (380 mm), and the driest month is September (100 mm).[8]
The islands receive more rainfall than Timor, Wetar, and the other islands of Nusa Tenggara to the west.
The ecoregion has 22 species of mammals. The dusky pademelon (Thylogale bruinii) is a kangaroo native to the Kai Islands, as well as the Aru Islands and southern New Guinea. The Kei myotis (Myotis stalkeri) is an endemic bat. The Indonesian tomb bat (Taphozous achates) is native to the ecoregion and neighboring Timor.
The islands are home to several species of mosaic-tailed rats (Melomys). In the Tanimbar islands, Melomys cooperae is endemic to Yamdena, and the Riama mosaic-tailed rat (Melomys howi) is endemic to the island of Selaru in the Tanimbar Islands. Bannister's rat (Melomys bannisteri) is endemic to the Kai Islands, and closely related to M. lutillus of New Guinea. The other rodents of the Kai islands are Hydromys chrysogaster and Uromys caudimaculatus, which are also found in New Guinea and Australia.[10]
The ecoregion is home to 225 bird species, including 21 endemic species and subspecies.[5] It corresponds to the Banda Sea Islands endemic bird area.[11]
A 2017 assessment found that 987 km2 (381 sq mi), 14% of the ecoregion, is in protected areas.[1] Protected areas include Kai Besar Nature Reserve.
References
^ abEric Dinerstein, David Olson, et al. (2017). An Ecoregion-Based Approach to Protecting Half the Terrestrial Realm, BioScience, Volume 67, Issue 6, June 2017, Pages 534–545; Supplemental material 2 table S1b. [1]
^ abcWikramanayake, Eric; Eric Dinerstein; Colby J. Loucks; et al. (2002). Terrestrial Ecoregions of the Indo-Pacific: a Conservation Assessment. Washington, DC: Island Press.
^Jepson, Paul, Nick Brickle and Yusup Chayadi (2001). "The conservation status of Tanimbar corella and blue-streaked lory on the Tanimbar Islands, Indonesia: results of a rapid contextual survey". Oryx Vol 35 No 3 July 2001.
^Purwanto, Yohanes (2001). "The Environmental Knowledge and the Utilization of Plants by Tanimbar-Kei Society, Southeast Moluccas, Indonesia". Tropics Vol. 11 (3):149-167, May 2002.
^Helgen, Kristofer M. (2003). "A review of the rodent fauna of Seram, Moluccas, with the description of a new subspecies of mosaic-tailed rat, Melomys rufescens paveli". Journal of Zoology, Zoological Society of London, (2003) 261, 165–172.
^BirdLife International (2020) "Endemic Bird Areas factsheet: Banda Sea Islands." Downloaded from http://www.birdlife.org on 20/05/2020.