The caatinga region covers more than 750,000 km² of north-east Brazil, from the north Atlantic coast of Ceará and Rio Grande do Norte states south to southern Bahia. This EBA is centred on the middle reaches of the São Francisco river and includes southern Ceará, eastern Piauí, western Paraíba and Pernambuco, and northern Bahia states. The climate is very dry with little cloud, sunlight exceeding 3,200 hours per year (Hueck 1978). The caatinga vegetation consists of a wide variety of semi-desert and dry deciduous forest formations, ranging from savanna dominated by cacti to thorn scrub and gallery forest with trees up to 15 m tall.

In the dry plains of western Pernambuco, most of the woody vegetation comprises tangled, brushy trees less than 4 m tall, with some emergent trees reaching 8-10 m (common species are Cnidoscolus phyllacanthus, Spondius tuberosa, Bursera leptophloeos and Ziziphus joazeiro: Rizzini 1979); a large terrestrial bromeliad Bromelia laciniosa is abundant and dominates the ground cover (Whitney and Pacheco 1994). In northern Bahia, trees and shrubs of the subfamilies Cesalpinioideae and Mimosoideae (both Leguminosae) are important components of the caatinga vegetation. Along rivers, including seasonally inundated watercourses and small rivers ('riachos'), and especially by the São Francisco, a more humid gallery woodland persists, sometimes with caraiba Tabebuia caraiba trees. Also in Bahia are areas of caatinga vegetation dominated by licuri Syagrus coronata palm trees.

As well as the five restricted-range species which are endemic to this EBA, a further five species whose ranges are considered to be greater than 50,000 km² (thus excluding them from the EBA analysis) are also endemic. These are Great Xenops Megaxenops parnaguae, Moustached Woodcreeper Xiphocolaptes falcirostris, Broad-tipped Hermit Phaethornis gounellei, Pectoral Antwren Herpsilochmus pectoralis and Yellow-faced Siskin Carduelis yarrellii (an estimation of their range size has been particularly difficult because they appear to show patchy distributions within a considerable area). Caprimulgus hirundinaceus and Gyalophylax hellmayri also have ranges which were difficult to judge owing to large gaps between records, and with better distributional information their ranges may also be shown to be greater than 50,000 km². Most of the 14 localities where G. hellmayri has been recorded are from a small part of northern Bahia and western Pernambuco, but there is a single sighting from north-east Piauí (Whitney and Pacheco 1994).

The two species of macaw found in this EBA do not overlap in range: Anodorhynchus leari is confined principally to the middle course of the Vaza-Barris south of the Raso da Catarina plateau in north-east Bahia, and Cyanopsitta spixii occurs only in the middle reaches of the São Francisco. The distribution of A. leari seems to fit well with that of licuri palms, whereas that of C. spixii matches that of the gallery woodland dominated by caraiba trees.

Picumnus fulvescens is distributed further east than the EBA's other restricted-range species, being found also in more humid woodlands associated with the Atlantic forests of Alagoas (EBA 071). Chordeiles vielliardi was described only in 1994 and is currently known from just one locality on the banks of the São Francisco in the centre of this EBA (Lencioni-Neto 1994), though it will undoubtedly be found in other localities when its voice is better known.

The general disturbance (agricultural expansion, grazing, hunting and burning) of this EBA is testimony to the prevalence of human pressure on the region. Much of the area has been populated since the late eighteenth century, and the general level of human disturbance increased 30 years ago when the Brazilian oil company, Petrobrás, became established: new roads into the region were immediately used by settlers and hunters. Relocation of many families to the region by government agencies is an additional problem (Hart 1991).

All the restricted-range species except for the two nightjars are considered threatened, and the widespread threatened species Megaxenops parnaguae, Xiphocolaptes falcirostris, Herpsilochmus pectoralis and Carduelis yarrellii (see 'Restricted-range species', above; all classified as Vulnerable) also have significant parts of their ranges in this EBA.

The two species of macaw are both on the brink of extinction in the wild. Currently there is only one wild individual (a male) of Cyanopsitta spixii, and attempts to reintroduce a wild-caught female alongside it failed in 1995; only three patches of its caraiba woodland habitat are known to remain in Bahia, totalling just c.30 km² (Juniper and Yamashita 1990). There is one main population of Anodorhynchus leari, which has been estimated at 117 individuals, but over the past 2-3 years trappers are thought to have taken c.20 birds; encouragingly, a new population of c.20 individuals was discovered several hundred kilometres from the main group in June 1995 (Munn 1995).

There are few protected areas within this EBA or, indeed, within the whole of the caatinga region: Capivara National Park (980 km²) holds Gyalophylax hellmayri and Picumnus fulvescens (as well as Megaxenops parnaguae and Carduelis yarrellii); Serra Negra Federal Biological Reserve (10 km²) holds Gyalophylax hellmayri (as well as Megaxenops parnaguae and Carduelis yarrellii); Aiuaba Federal Ecological Station (115 km²) lies within the EBA but lacks ornithological data. The main breeding site for Anodorhynchus leari (Toca cliffs) was bought by Fundação Biodiversitas, and lies adjacent to the Raso da Catarina Ecological Station (998 km²), but is heavily used for animal grazing by local people.

Stattersfield, A. J., Crosby, M. J., Long, A. J. and Wege, D. C. (1998) Endemic Bird Areas of the World. Priorities for biodiversity conservation. BirdLife Conservation Series 7. Cambridge, UK: BirdLife International.

Recommended citation
BirdLife International (2024) Endemic Bird Area factsheet: North-east Brazilian caatinga. Downloaded from https://datazone.birdlife.org/eba/factsheet/66 on 22/12/2024.