Threatened birds are not distributed evenly; some areas hold many more threatened species than others. This is in part because overall species diversity is higher in some countries, but also owing to the distribution of past and present threatening processes. Brazil, Peru and Indonesia hold the most threatened birds, many of which are endemic.
Regional and national variations in numbers of threatened birds depend on a combination of evolutionary history (which influences species diversity, range size, behaviour and ecology) and past and present threatening processes. Certain countries, mainly in the tropics, have particularly high numbers of threatened species and are therefore priorities for international conservation action. Ten countries have more than 70 globally threatened birds, with Brazil, Peru and Indonesia heading the list, holding 152, 128 and 122 respectively (figure a). These countries also rank highly for numbers of threatened mammal species (Hilton-Taylor 2000). Furthermore, they support a particularly high number of threatened endemic birds (those restricted to just a single country): Brazil has 79, Peru has 37 and Indonesia has 72. A particularly high proportion of threatened birds found in the Philippines are endemic: 78%. With dependent territories included, France ranks sixth in the list of countries with the most threatened birds, supporting 95.
The overall avifaunas of some countries are particularly threatened. A graph of the number of threatened species plotted against the total number of bird species for each country shows that numerous countries are situated well above the regression line, i.e. they support more threatened species than expected (figure b, BirdLife International 2008). The ten countries with the most threatened avifaunas include seven of the most important in terms of absolute numbers of threatened birds (e.g. Indonesia, Peru and Brazil). The analysis also highlights several territories that have highly threatened avifaunas despite relatively low total avian diversity. For example, French Polynesia supports 92 bird species, of which 37 are globally threatened, and Norfolk Island (to Australia) supports 44 species, of which 15 are globally threatened. Some countries also hold far fewer threatened species than expected, i.e. they fall far below the regression line. These include very small countries with no globally threatened birds (e.g. Monaco and the Faroe Islands), but also larger ones such as Suriname and French Guiana, with avifaunas of more than 600 species. Fortunately, few bird species are yet threatened in these countries because they still hold vast tracts of largely unpopulated forest.
Related Case Studies in other sections
Compiled 2004, updated 2008, 2011, 2012
BirdLife International (2012) Some countries are particularly important for threatened birds. Presented as part of the BirdLife State of the world's birds website. Available from: http://birdlife.org/datazone/sowb/casestudy/112. Checked: 29/05/2016