The Birds of Liberia
Total Page：16
File Type：pdf, Size：1020Kb
THE BIRDS OF LIBERIA This Check-List has been sponsored by the German Agency for Technical Cooperation (GTZ) and by the German Forestry Mis¬ sion to Liberia (G M) c/o Forestry Developme t Authority Monrovia, Liberia. A Preliminary Check-List with Status and Open Questions Cover: Wooly-necked Stork and Hadada Ibis. Photo: W.Gatter WULF GATTER White-breasted Guinea Fowl Agelastes meleagrides Downy young, subadult and adult bird. The most threatened bird of West Africa. Gattee: The Birds of Liberia 689 Verh. orn. Ges. Bayern 24, 1988: 689 723 The Birds of Liberia (West Africa) A Preliminary List with Status and Open Questions By Wulf Gatter* The first important investigation of Liberia s avifauna was carried out by Büttikofer (1890, etc) at the end of the last Century. In 1926, an expedition from Harvard Univer- sity visited Liberia for several months. Allen (1930) analyzed their results and combi- ned them with previously published findings into a list of The Birds of Liberia . With additions from Bouet (1931) and Ra d (1951), the list reached 310 known species of birds in Liberia. The investigations at Mt. Nimba (Colston & Curry-Lindahl 1985) where Guinea savanna and rain forest meet, with a further important mountain com- ponent, came up with a list of 385 species. Fig. 1 Map of Liberia with important Observation poi ts. K rte von Liberia mit wichtigen Beobach¬ tungsorten. Mit einem Druckkostenzuschuß des Verfassers 690 [Verh. orn. Ges. Bayern 24, Heft 6, 1988] Gatter: The Birds of Liberia 691 Together with the results of the rain forest region of South-East Liberia (390 spe- Vegetation zones cies) and the Monrovia region (408 species) by the author and others, three sub-regions Coastal savanna and mangrove: The man-made savanna extends as a beit along the of the country were explored for the first time usin modern methods of investigation. coast up to 25 km into the country and is marked by various types of grassland-forest Since then the exploration of the unknown north-west after 1983 has produced a lar e mosaic, the remains of gallery forests, local patches of primary swamp forest and va¬ number of new findings and closed the most important gap in our knowledge. rious types of secondary forest. Along the coast and river estuaries man rove Vegeta¬ Since 1981 efforts have been made to carry through nationwide investi ations and tion covers altogether about 310 sq. km. Numerous lagoons are located along the to coordinate activities of observers, the numbers of whom remain low to this day. An coast, generally behind the beach sand bar. Depending on their development, there accurate account of the state of knowledge at the present time is much needed by the are different types of salt- and freshwater lagoons with different Vegetation types authorities of the country, as well as by the increasing number of interested persons. (Hasselmann 1979, Gatter 1988). Foliowing the initial project of drawing up an extensive annotated checklist of the birds of iberia, the necessity of starting off with a short list with information on Sta¬ Tropical rain forest zone: tus and unanswered questions became apparent. Tropical rain forest once covered all of Liberia except for a few rock outcrops, some Liberia is the only country along the Southern coast of West Africa which was re- sandy areas along the coast and the mangrove swamps (Gatter & Mattes 1987). stricted originally to a single Vegetation zone along its north-south extension the The most recent survey (1979 1982) of forested areas in Liberia reveals that 38% lowland rain forest. Taking this into account, its record of 590 species shows a very (42,000 sq. km.) of Liberia s 111,369 sq. km. was still covered by primary and very old rieh avifauna compared to other countries that have been extensively explored since secondary forest. Of this percentage, all e cept Sapo National Park had been leased to colonial times and which have Vegetation zones ranging from evergreen rain forest timber cropping concessions by 1987. through to the Sudan zone (e. g. Ivory coast with 683 species [Thiollay] 1985) or Ghana The annual destruction of primary forest by farmers, who have been enabled with 721 species [Grimes 1987]). Between 122 and 127 of Liberia s bird species (22%) through the road construction by logging concessions, to set up their f arms in the Cen¬ originate from the Palaearctic re ion. ter of primary forest areas, was estimated at the beginning of the 1980’s to be 1 %, i. e. 400 sq. km. Topography, climate and main Vegetation zones In the meantime it has increased, in particular in Western Liberia, and risen prob- The Coastal lowland (up to 30 m above sea level) extends forty kilometres Inland. It ably to 500 sq. km per year and more. is followed by a beit of rolling hills at an elevation of some 300 m and mountain r nges The rain forest beit can be divided into the evergreen rain forest zone in the south reaching 600 m. The northern highlands are table lands at over 500 m and mountain with more than 2 000 mm annual rainfall and a semideciduous forest zone in the north ranges reaching 1385 m at Mt. Nimba and 1350 m in the Wologizi Range (Schulze with less rain, and a transition zone between these two zones. 1973). Another 40% of the country is covered by secondary forest, which is slashed and burned within the f arming System of shifting cultivation, with 7 25 year or even lon- Climate ger fallow periods. The remainin areas are covered by plantations (mainly rubber), intensively used f armland and the following successions, and man-made savannas re- Liberia s position near the equator between 4°20 N and 8°30 N places the country sulting from repeated shif ting cultivation (Gatter 1984). within the so-called inner wet tropics with a steady, warm temperature throughout the year. Southern Guinea zone: There is a rainy season from April to November and a dry season from December Along the northern edge of the forest zone there is a forest grassland mosaic adja- to March, with a short mid-dry in Coastal and Southern parts of the country for not lon- cent to the Mt. Nimba region. In the most northern sector of Lofa County it forms an ger than 3 weeks in July/August. Along the coast the annual rainfall ranges from interrupted beit of bare rock, farmland with conspicuous Stands of oil palm, patches 3 000 mm in the east (Harper) to 4800 mm in the west (Robertsport) climbing above of grass savanna and forest. 5 000 mm on the nearby Cape Mount. Nearly all of this area was covered with forest and rieh farmland some eighty years In the interior from Zwedru (South-East) to Ganta and Zorzor (North-West) it de- ago, but today is strongly degraded by the dense human population. creases to about 2 000 mm and increases again to more than 3 000 mm in the northern highlands of the Nimba and Lofa region. Presentation of Data The annual mean temperature of the Coastal areas (2 5°- 2 6° C) compares with the in¬ The families appearing in the systematic list follow earlier checklists on Gambian terior (27°C) near Zwedru and Salala, and decreases in the northern highlands to birds (Gore 1981), Nigerian birds (Elgood 1982) and Ghanaian birds (Grimes 1987). 23.8°C at Kolahun and 19.6°C at Mt. Nimba. Within these taxa, genera and species are in alphabetic sequence. Beside this the na- mes used in the list usually follows those used in Grimes (1987). 692 [Verh. orn. Ges. Bayern 24, Heft 6, 1988] Gatter: The Birds of Liberia 693 The status of each species is summarized by the following abbreviations: RB resident breeder R(B) resident, but breeding unproven (RB) resident and breeding status unproven. Species may leave during the rains. PM Palaearctic migrant •NM Nearctic migrant, Neotropical migrant AfM migrates within Liberia and neighbouring areas AfM/B migrates to and from Liberia to breed in Liberia AfM/NB migrates to and from Liberia to spend the non-breedin season in Liberia, V vagrant ? indicates doubt about the status immediately preceding the question mark, but not of occurrence 5 CO Where there is ncertainty about the occurrence of a species, it is placed in square brackets. Most of these species should occur in Liberia, but records have not been def- 3 =! X\ Xl r3 ,3 & P Ph * * * * initely confirmed or it is believed that the species has been overlooked. Ph * * Ph * Ph Ph Ph Ph This column is followed by information on abundance: ?h 3 ?h 3 a abundant c common u uncommon r rare u-c 0 means the species is not uncommon, or is locally uncommon and locally common H uScN uncommon in south, common in north etc. Ph H Cß PQ C/3 PS > PLh > > Ph > h Ph > <i The next column deals with open questions (in brackets) h (Ec) ecology, habitat, habits O (Ph) phenology, migrations, migration direction, annual cycles such as breeding and moult, numbers SYSTEMATIC LIST (ZG) zoogeography, origin, distribution (Sy) systematics CD Ph (Dy) population dynamics (short term and lon term) h-j C CD J-, o B f-l ?H (*) all possible further Information needed OJ 'S Ph Ph S Ph o l o3 Ph CO Sh <D H The last column behind the brackets gives an indication of habitats, distribution, re- 0 b öfl « O 5 CO o CD stricted areas such as the name of a town.