Welcome to Wallacea

 

sulawesi scops owl
Tangkoko NR 20/07/2023

Wallacea is the name for the biogeographic zone between Wallace’s and Lydekker’s Lines, which trace the Sunda and Sahul tectonic plates of the earth’s crust, respectively. Wallace’s Line marks the eastern boundary of the Oriental fauna region, in which can be found typically Southeast Asian bird groups and other animals, such as elephants, cats, and monkeys. Running between Bali and Lombok, and Borneo and Sulawesi, the line was named after the intrepid British naturalist Alfred Russell Wallace, who helped Charles Darwin to formulate the Theory of Evolution by Natural Selection. In a similar way, Lydekker’s Line marks the western boundary of the Australo-Papuan faunal region, where approximately half of the world’s birds (passerines) originated, and half of the mammal fauna comprises marsupials, such as the wallabies and possums. Wallacea is therefore, at least partly, a transition zone between these two great biogeographic regions, with a mixture of animal groups from both. However, its myriad islands, a result of a turbulent geological past, have resulted in the evolution of many bird groups or species that are endemic (unique) to Wallacea. In this respect, the islands of Wallacea resemble those of the famous Galapagos Islands, where there was massive radiation of species from a small original stock of species from the South American mainland. Wallacea comprises three sub-regions: the large island of Sulawesi (Celebes) and its many satellite island groups, the Moluccas (Maluku) and the Lesser Sundas (Nusa Tenggara). PBC provides tours to Sulawesi and to the North Moluccan island of Halmahera. SULAWESI Sulawesi has been ranked by Birdlife International as the most endemic bird area on earth.   The main island of Sulawesi is home to no less than 12 endemic genera and 41 endemic species.  A further 56 species are endemic to the Sulawesi sub-region, (which includes neighboring islands, such as Sula and Banggai) and most of these can be found on the main island.   Birdwatchers who visit this wondrous K-shaped landform are guaranteed to find a wealth of new and exciting species. Birds are not the only unique animals on this amazing island.  Sulawesi also supports 79 endemic mammals - including an unusual dwarf buffalo called the Anoa, a bizarre pig known as the Babirusa, the Sulawesi Bear Cuscus, the Spectral Tarsier and the Crested Black Macaque. Fortunately, Sulawesi's forests have been afforded some protection.  The island boasts eight national parks.  Four of these are forested, while the other 4 are marine areas.   A network of protected nature reserves also exists.  PBC tours are specifically tailored to ensure the best opportunity of seeing the widest range of bird species.  We visit Tangkoko Nature Reserve and Bogani Nani Wartabone National Park on the Northern Peninsula, and Lore Lindu National Park in Central Sulawesi. Despite the small size of Tangkoko Nature Reserve, it is home to 9 Kingfisher species.  It is also the place where you have the best chance of seeing the elusive Red-Backed Thrush and the Small Sulawesi Hanging Parrot.  Our trips here include spotlighting at night, which provides the opportunity to see one of Sulawesi's most curious mammals - the Spectral Tarsier.  Bogani Nani Wartabone National Park (formerly known as "Dumoga-Bone") comprises 3000 square kilometers of protected tropical jungle and ranges from sea-level to 1920 meters.  It supports a large proportion of the wildlife that is found at low to middle altitudes on Sulawesi.   The most eagerly sought-after species here is the Maleo - a chicken-sized ground dweller that is famous for excavating nest holes in volcanically heated soil to incubate its eggs.  Other ornithological delights include the Sulawesi Serpent Eagle and Sulawesi Hawk Eagle, Golden-mantled and Yellow-breasted Racquet-tails, Knobbed and Sulawesi Hornbills and Purple-winged Roller. Lore Lindu National Park (2290 square kilometers) is home to almost 80% of Sulawesi's endemic birds.  The park is elevated to an altitude of 2,350 meters and includes spectacular montane rainforest around Mount Rorekatimbu.   The lowland forest in the park has become badly degraded, so it is the higher-altitude endemic birds that we concentrate on when we come here.   Among the most spectacular of these are the Fiery-browed Starling and the incomparable Purple-bearded Bee Eater.   Others include the Sulawesi Woodcock, Geomalia, Great Shortwing, and Crimson-crowned Flowerpecker.   Also found here is the Giant Civet, whose huge paws enable it to climb trees and predate Sulawesi Hornbills!

HALMAHERA

Halmahera is another K-shaped island, and another region of enormous importance for endemic birds.  Here and in the surrounding islands, are found 26 endemic bird species (including 4 endemic, single-species genera).  Ten further species on Halmahera are endemic to the Moluccas.

Two species of bird of paradise are found in Halmahera.  These are the western-most members of the family and neither of them is found in New Guinea:  Wallace's Standardwing is a truly extraordinary creature.  The plumage of the male includes a pair of long white pennant feathers that extend from the joints of its wings.  These are extended most prominently during its parachuting courtship displays.  The Paradise Crow is less spectacular in appearance - looking more like a plain crow than a Bird of Paradise.

Most birdwatching activities on Halmahera are conducted at Kali Batu Putih.  This unprotected area is the location of a display tree, where Wallace's Standardwing can be reliably observed.  It is also the best-known site for another spectacular and highly elusive bird; the Ivory-breasted Pitta.  Other sought-after species here include the White (Umbrella) Cockatoo, Chattering Lory, Goliath Coucal and Purple Roller.

Of the 26 regional endemics, 22 can be found at Kali Batu Putih.   The remaining four are difficult to locate.  Carunculated Fruit Dove is known only from neighbouring Obi Island.  Moluccan Woodcock is confined to Obi and Bacan.  Moluccan Cuckoo is known from 5 specimens collected in 1931 (though a sighting was reported in the lowlands of Halmahera in 1996).  The Invisible Rail mostly lives up to its name!  

In spite of the extensive degradation of Halmahera's forests, most endemic birds on the island are not currently threatened with extinction.  Those which are threatened are Invisible Rail, Moluccan Woodcock, Moluccan Scrubfowl, White Cockatoo, Chattering Lory and Carunculated Fruit Dove (all of which are classified as Vulnerable).