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Scaly Ground-roller Geobiastes squamiger

Justification
This species is classified as Vulnerable because population declines are predicted to become rapid over the next three generations owing to the destruction and degradation of its forest habitat.

Taxonomic source(s)
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.

Taxonomic note
Geobiastes squamiger (del Hoyo and Collar 2014) was previously placed in the genus Brachypteracias. Gender agreement of species name follows David and Gosselin (2002b).

Synonym(s)
Brachypteracias squamiger Lafresnaye, 1838, Brachypteracias squamigera Dowsett and Forbes-Watson (1993), Brachypteracias squamigera BirdLife International (2000), Brachypteracias squamigera Sibley and Monroe (1990, 1993)

Identification
27-31 cm. Thickset, terrestrial bird with strong bill. Head covered in dense black-and-white scaly pattern. Coppery-brown mantle, greenish wings with whitish tips to coverts. Tail reddish-brown in centre, with blue tips and black subterminal marks to outer feathers. Black eye-stripe and line across cheeks, and paler underparts heavily marked with black crescents. Thick and fairly long, greyish bill. Long, pink legs. Similar spp. Combination of heavily scaled plumage, long pink legs and terrestrial behaviour make this bird unmistakable. Voice Call is low, emphatic boop, given once every 10 seconds or so. Hints Hops around on the floor of lowland rainforest, often in rather open areas, catching terrestrial invertebrates such as worms, beetles and cockroaches.

Distribution and population
Brachypteracias squamiger is found only below 1,000 m and thus is one of the few true lowland rainforest species in Madagascar. It occurs in lowland forest throughout the eastern rainforest belt from Marojejy south to Andohahela. However, there is much less lowland forest in the southern part of this belt (ZICOMA 1999).

Population justification
The population is estimated to number 2,500-9,999 individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. This estimate is equivalent to 1,667-6,666 mature individuals, rounded here to 1,500-7,000 mature individuals. The true population size may lie at the upper end of this estimate, as the species is described as fairly common.

Trend justification
The population is suspected to have declined at a moderate rate over the last ten years, in line with habitat loss and degradation. The rate of decline is expected to become rapid over the next ten years.

Ecology
This species seems to prefer low-altitude areas of undisturbed, primary rainforest with damp soils, dark and tangled undergrowth, low herbaceous vegetation and a layer of leaf-litter and branches (Langrand 1990). It feeds on invertebrates, chiefly earthworms but also snails, centipedes, spiders, ants and beetles, and more rarely small vertebrates (e.g. frogs) (Langrand 1990). It nests in a tunnel, dug in a bank or slope in the forest, between October and January.

Threats
The principal threat to its forest habitat is from slash-and-burn cultivation by subsistence farmers, which results in progressively more degraded regrowth and leads eventually to bracken-covered areas or grassland (Stattersfield et al. 1998). Much of the forest on the eastern coastal plain has either already been cleared or is highly degraded, remaining habitat is under pressure from the increasing human population and commercial logging is an additional threat in some areas (Jenkins 1987; ZICOMA 1999). If present trends continue, the remaining unprotected forest, especially at the lower altitudes where this species is more abundant, will disappear within decades (Stattersfield et al. 1998). Predation by village dogs and hunting for food are possibly threats (ZICOMA 1999).

Conservation Actions Underway
The species is known from the following protected areas: Ambatovaky Special Reserve, Andohahela National Park, Andringitra National Park, Anjanaharibe Classified Forest, Anjanaharibe-South Special Reserve, Betampona Strict Reserve, Haute Rantabe Classified Forest, Mananara-North National Park, Mantadia National Park, Marojejy National Park, Masoala National Park, Midongy-South National Park, Ramanofana National Park, Tsitongambarika Classified Forest, Vondrozo Classified Forest and Zahamena National Park (ZICOMA 1999).Conservation Actions Proposed
Determine its home-range size and its dispersal capability across deforested areas, in order to clarify the impact of forest fragmentation on its population structure. Carry out surveys in order to estimate its population size. Compare relative abundance and densities in protected and unprotected habitat (M. Rabenandrasana in litt. 2007). Conduct regular surveys to monitor population trends. Monitor rates of habitat loss and degradation. Assess the potential threats from domestic dogs and hunting pressure. Increase the area of suitable habitat that has protected status.

References
Collar, N. J.; Stuart, S. N. 1985. Threatened birds of Africa and related islands: the ICBP/IUCN Red Data Book. International Council for Bird Preservation, and International Union for Conservation of Nature and Natural Resources, Cambridge, U.K.

Jenkins, M. D. 1987. Madagascar: an environmental profile. International Union for Conservation of Nature and Natural Resources, Cambridge, U.K.

Langrand, O. 1990. Guide to the birds of Madagascar. Yale University Press, New Haven, USA.

Stattersfield, A. J.; Crosby, M. J.; Long, A. J.; Wege, D. C. 1998. Endemic bird areas of the world: priorities for bird conservation. BirdLife International, Cambridge, U.K.

ZICOMA. 1999. Zones d'Importance pour la Conservation des Oiseaux a Madagascar.

Further web sources of information
Explore HBW Alive for further information on this species

Search for photos and videos, and hear sounds of this species from the Internet Bird Collection

Text account compilers
Ekstrom, J., Evans, M., Shutes, S., Starkey, M., Symes, A., Taylor, J.

Contributors
Hawkins, F., Rabenandrasana, M.

IUCN Red List evaluators
Butchart, S., Taylor, J.

Recommended citation
BirdLife International (2014) Species factsheet: Geobiastes squamiger. Downloaded from http://www.birdlife.org on 02/10/2014. Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 02/10/2014.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Key facts
Current IUCN Red List category Vulnerable
Family Brachypteraciidae (Ground-rollers)
Species name author Lafresnaye, 1838
Population size 1500-7000 mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 21,300 km2
Country endemic? Yes
Links to further information
- Additional Information on this species