Regional Introductions
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Regional Introductions REGIONAL INTRODUCTIONS HE WORLD has been divided up regionally The text presents sections on: for presentation of the EBA data. The limits of • Restricted-range species, with information on Tthe chosen regions (see Figure 1) largely where they occur, the types of habitats which they reflect biogeography, but some compromises have favour, the key sources of information and some had to be made; thus the Palearctic and Oriental of the taxonomic problems encountered in the faunal regions are both split between two of the EBA analysis. regions used here. • Endemic Bird Areas, with a description of pat- This chapter presents introductory information terns of endemism, some of the characteristics of region by region. For each there is provided a map the EBAs and levels of knowledge. displaying all the EBAs which fall within the region, a box of key facts and a table of summary EBA data. • Threats and conservation, with an indication of habitat loss, other threats to EBAs and their birds, and selected important conservation initiatives. North and Central Pacific Islands America Pacific Islands Continental Asia South-East Asian Islands, Africa, Europe and New Guinea and South the Middle East Australia America Figure 1. Regional division of the world used in this book. The areas shown correspond to those covered by the regional maps (Figures 2–7). NORTH AND CENTRAL AMERICA HIS REGION includes North and Central Socorro and Cocos are included (see Box 1 for key TAmerica through to the Darién lowlands of facts). eastern Panama and north-west Colombia. The Greater and Lesser Antillean islands of the Carib- Restricted-range species bean are also covered here, as are other islands in the Of the c.200 restricted-range species in the mainland Caribbean Sea such as Cozumel, Providence and San part of this region, only a few are found in North Andrés. On the Pacific side, the islands of Guadalupe, America, the vast majority being associated with 57 Endemic Bird Areas of the World America (Lack 1976), and just four restricted-range Box 1. Key facts for North and Central America. bird species are shared between the islands and the Numbers of: continental landmass. The most highly differentiated 324 Restricted-range species species include Palmchat Dulus dominicus, which is 69 Threatened restricted-range species endemic to Hispaniola and is the only member of its 30 EBAs 17 Secondary Areas family, and several todies (Todidae), an endemic 29 Countries with EBAs Caribbean family. Knowledge of birds in this region is, for the most EBAs with high numbers of restricted-range part, good, with a number of excellent regional and species national publications documenting in some detail • Costa Rica and Panama highlands (EBA 020), 52 species their ecology, distribution and status (e.g. Slud 1964, • Jamaica (EBA 027), 35 species Monroe 1968, AOU 1983, Bond 1985, Ridgely and • Hispaniola (EBA 028), 34 species Gwynne 1989, Stiles and Skutch 1989, Collar et al. EBAs which are especially distinct at the generic 1992, Howell and Webb 1995a, Stotz et al. 1996), level each benefiting from work by several large, active • Costa Rica and Panama highlands (EBA 020), museums in both North and Central America. How- 8 endemic genera ever, the region is still in need of major field surveys, • Lesser Antilles (EBA 030), 7 endemic genera with a number of areas in the Greater Antilles and • Hispaniola (EBA 028), 6 endemic genera Central America being un- or under-explored orni- EBAs with high numbers of threatened re- thologically. stricted-range species Although only one species from the region has • Lesser Antilles (EBA 030), 9 species been described as new to science in the last five years • Hispaniola (EBA 028), 7 species (White-fronted Swift Cypseloides storeri), species EBAs with high numbers of Critical and limits have been redefined for many taxa, resulting in Endangered endemic species • Lesser Antilles (EBA 030), 4 species numerous new species-level taxa. This is due to the unparalleled attention given to the New World Examples of EBAs critically in need of avifauna by taxonomists and field biologists within conservation action • Sierra Madre Occidental and trans-Mexican the region—although it should be noted that this range (EBA 006) attention has not focused to the same extent on the • Sierra Madre del Sur (EBA 009) Caribbean avifauna. As an example of how fluid the • Cuba (EBA 025) taxonomy is within this region, almost 30 species Countries with particularly high numbers of have been added to the North American list since restricted-range species 1995 due to the taxonomic splitting of species (AOU • Panama, 91 species 1995a, 1997). Similarly, Howell and Webb (1995a) • Mexico, 83 species considered that, for 15% of the 1,070 species in • Costa Rica, 77 species Mexico and northern Central America, there still Countries with high numbers of threatened remains considerable debate about their taxonomic restricted-range species status. • Mexico, 23 species Endemic Bird Areas There are only two EBAs in North America: Califor- forests in the mountain ranges of Central America. In nia (EBA 001), which is largely in the USA but the Caribbean, which has over 130 restricted-range extends into northern Baja California, Mexico; and species, nearly every island supports at least one the Northern Sierra Madre Oriental (EBA 010), restricted-range species, such species having a vari- which is largely in northern Mexico but just overlaps ety of habitat and altitudinal preferences. southern Texas, USA. The majority (19) of the EBAs There are no families endemic to the mainland, as lie solely in (the mainland of) Central America, with Central America forms a land-bridge between North a further six covering the Caribbean islands. Three and South America, and thus has avifaunal affinities Pacific Ocean islands of the region form three sepa- with both continents. However, very few of the rate EBAs. A total of 17 Secondary Areas, including restricted-range species extend out of Central America several on small Caribbean islands, complete the south into South America. The Greater Antilles have analysis (see Figure 2 for location of EBAs and avifaunal similarities with North and Central America, Secondary Areas, and Table 1 for EBA summary and the Lesser Antilles with South America, but data). speciation has resulted in an endemic Caribbean An important feature of the region is the series of avifauna which is quite distinct from that of mainland mountain chains which effectively separate the Pacific 58 Regional Introductions lowlands from the Gulf/Caribbean lowlands. EBAs (EBA 008), North-east Mexican Gulf slope (EBA occur in the lowlands on both of these slopes, e.g. the 011), and North Central American Pacific slope North Central American Pacific slope (EBA 017) (EBA 017)—are especially vulnerable to habitat and the South Central American Pacific slope (EBA loss, being located along the coastal plains of Central 021) on the western side and the Central American America where the human population is at its most Caribbean slope (EBA 019) on the east. There are dense. Long-standing land use for agriculture has also EBAs in the higher isolated mountainous areas intensified over the past 25 years in this area, espe- such as the Costa Rica and Panama highlands (EBA cially for cattle-ranching and cash crops (e.g. citrus 020) and Darién highlands (EBA 024). The Costa fruit). Likewise, the predominantly coniferous forest Rica and Panama highlands EBA, although only EBAs of the Sierra Madre Occidental and trans- 23,000 km2 in size, has 52 restricted-range species Mexican range (EBA 006) and Northern Sierra Madre confined to it, one of the highest numbers of any of Oriental (EBA 010) have lost most of their old- the EBAs identified by the project. growth forest from logging over the past 50 years, In a few cases a number of smaller islands have and a similar fate has hit the mainly lowland humid been grouped together to form single EBAs, notably forest EBAs of Los Tuxtlas and Uxpanapa (EBA the Lesser Antilles (EBA 030), which encompasses 013), Central American Caribbean slope (EBA 019) the arc of islands from Anguilla south to Grenada and and South Central American Pacific slope (EBA incorporates 12 geopolitical units. Several of these 021). islands support their own single-island endemics; There are still extensive areas of montane ever- indeed St Lucia (616 km2) has four species unique to green forest left in some EBAs—the Sierra Madre del it, but many more restricted-range species are shared Sur (EBA 009), Southern Sierra Madre Oriental between nearby islands, thus making the whole of the (EBA 012), North Central American highlands (EBA Lesser Antilles one EBA. 018), Costa Rica and Panama highlands (EBA 020) The topography of mainland Central America is and Darién highlands (EBA 024)—but even these complex, especially in the central Mexican high- have been affected by agriculture, especially for lands, where it has been difficult to delineate the coffee and subsistence farming, and logging is in- boundaries of the EBAs precisely. In other highland creasingly having a severe impact, e.g. in the South- areas, and on the Caribbean and Pacific slopes in ern Sierra Madre Oriental. Costa Rica and Panama in particular, poor knowledge The Caribbean EBAs—notably Cuba (EBA 025) of the altitudinal ranges for restricted-range species and Hispaniola (EBA 028)—have also suffered wide- means that the boundaries of the EBAs involved (e.g. spread habitat modification due to cultivation (e.g. of EBAs 020, 021) can only be approximately defined; coffee, sugar-cane or bananas) and development for this problem is exacerbated by the loss of habitat the tourist industry, with introduced predators (e.g. which radically affects species distributions and rats, mongooses and cats) being a particular problem altitudinal preferences.