Scaly Ground-Roller Geobiastes squamiger Scientific name definitions

25–32 cm; male 145–165 g (1 Safford, R. J., and A. F. A. Hawkins, Editors (2013). The Birds of Africa. Volume 8. The Malagasy Region. Christopher Helm, London, UK. Close ), female 137·5–140 g (2 Rakotoarisoa, J.E. and Be, B. (2004). Breeding and foraging behaviour and habitat characteristics of the Scaly Ground-roller Geobiastes squamigerus in Madagascar. Ostrich. 75(1-2): 25-31. Close ). Second-largest rainforest ground-roller, plump and long-legged. Both sexes have head and underparts buffish white with brown and black scaling, distinctive irregular black bands on central crown , behind eye and across ear-coverts below eye, belly and vent less scaly and more buffy; rufous hindcollar ; bronzy green scapulars, tertials and wing-coverts, white crescent-shaped markings outlined in turquoise or blue-grey and black on lower mantle, scapulars and wing-coverts; dark brown secondaries and primaries, buffish-white wingbar visible in flight; tail rufous with bronzy green base, outer feathers with dark subterminal band and sky-blue tip, four central feathers completely bronzy green; iris brown, orange-pink fleshy eyering extending to distinctive patch behind eye; stout, slightly hooked bill dull blackish brown, slightly paler cutting edges, nostrils near base of upper mandible covered by bristly feathers; legs pink-orange, claws dull white. Female apparently slightly smaller (e.g in wing length, mean 118·5 mm versus 125·5 mm in male, as well as mass) (2 Rakotoarisoa, J.E. and Be, B. (2004). Breeding and foraging behaviour and habitat characteristics of the Scaly Ground-roller Geobiastes squamigerus in Madagascar. Ostrich. 75(1-2): 25-31. Close ). Juvenile dull rufous over crown, nape, breast and flanks, the chin and centre of abdomen are dingy white, and black stripes on neck-sides are present as on adult, while patterns of flight and tail feathers are similar to those of adults, but wing-covert markings much less distinct (3 Raveloson, B. and Safford, R. (2012). Photospot: Juvenile Scaly Ground-roller Geobiastes squamiger. Bull. African Bird Club. 19(1): 79-80. Close ).

E Madagascar, from Marojejy National Park and Anjanaharibe Sud Special Reserve in N to Andohahela National Park in S.

Occupies humid lowland to lower mid-altitude rainforest, with a marked predilection for undisturbed dark areas with large trees, preferring dense and tangled vegetation with damp soil and deep leaf litter, but also occurring in relatively open understorey; recently observed in secondary growth and edge habitats, suggesting it may show some tolerance to habitat degradation. May be found in drier environments than B. leptosomus, but often frequents damp valley bottoms. Occurs from sea-level up to 950 m, but mostly below 600 m; an old record from 1800 m is probably erroneous.

Generally sedentary, but in one area abundance noted to change with weather and associated drying-out of the species’ feeding habitat (4 Thompson, P. M., and M. I. Evans (1992) The threatened birds of Ambatovaky Special Reserve, Madagascar. Bird Conservation International 2: 221-237. Close ). Flees perceived danger by running, rather than flying, even in areas of extremely tangled undergrowth (5 Evans, M. I., J. W. Duckworth, A. F. A. Hawkins, R. J. Safford, B. C. Sheldon, and R. J. Wilkinson (1992) Key bird species of Marojejy Strict Nature Reserve, Madagascar. Bird Conservation International 2: 201–220. Close ).

Invertebrates, mainly earthworms (Pheretima sp., Megascoleidae) (2 Rakotoarisoa, J.E. and Be, B. (2004). Breeding and foraging behaviour and habitat characteristics of the Scaly Ground-roller Geobiastes squamigerus in Madagascar. Ostrich. 75(1-2): 25-31. Close ), but also ants, beetles, caterpillars, centipedes (Scolopendra morsitons, Myriapodes) (2 Rakotoarisoa, J.E. and Be, B. (2004). Breeding and foraging behaviour and habitat characteristics of the Scaly Ground-roller Geobiastes squamigerus in Madagascar. Ostrich. 75(1-2): 25-31. Close ), crickets, millipedes (Diplopoda) (2 Rakotoarisoa, J.E. and Be, B. (2004). Breeding and foraging behaviour and habitat characteristics of the Scaly Ground-roller Geobiastes squamigerus in Madagascar. Ostrich. 75(1-2): 25-31. Close ), pill-millipedes (Sphaerotheriida), snails (Sphaeroterium sp., Gastropoda) (2 Rakotoarisoa, J.E. and Be, B. (2004). Breeding and foraging behaviour and habitat characteristics of the Scaly Ground-roller Geobiastes squamigerus in Madagascar. Ostrich. 75(1-2): 25-31. Close ) and spiders; also small vertebrates, such as frogs, dwarf chameleons (Brookesia) (1 Safford, R. J., and A. F. A. Hawkins, Editors (2013). The Birds of Africa. Volume 8. The Malagasy Region. Christopher Helm, London, UK. Close ), plated lizards (Zonosaurus) (1 Safford, R. J., and A. F. A. Hawkins, Editors (2013). The Birds of Africa. Volume 8. The Malagasy Region. Christopher Helm, London, UK. Close ), and neonate mammals, e.g. shrew tenrecs (Microgale, Tenrecidae) (1 Safford, R. J., and A. F. A. Hawkins, Editors (2013). The Birds of Africa. Volume 8. The Malagasy Region. Christopher Helm, London, UK. Close ) and a rat (Rattus). More than 90% of food fed to a nestling consisted of invertebrates, while separate study found that adults brought 71·5% invertebrates, 7·5% vertebrates and 21% unidentified items to nests, with earthworms and centipedes the most numerous identified prey types, representing 55% and 21%, respectively; among insects, 25% were Coleoptera, 19% Hymenoptera, 19% Lepidoptera and 37% unidentified (2 Rakotoarisoa, J.E. and Be, B. (2004). Breeding and foraging behaviour and habitat characteristics of the Scaly Ground-roller Geobiastes squamigerus in Madagascar. Ostrich. 75(1-2): 25-31. Close ). Terrestrial counterpart of B. leptosomus; mainly searches the ground (80·3% of items taken terrestrially in one study) (2 Rakotoarisoa, J.E. and Be, B. (2004). Breeding and foraging behaviour and habitat characteristics of the Scaly Ground-roller Geobiastes squamigerus in Madagascar. Ostrich. 75(1-2): 25-31. Close ) by alternating periods of attentive waiting (listening and watching) (2 Rakotoarisoa, J.E. and Be, B. (2004). Breeding and foraging behaviour and habitat characteristics of the Scaly Ground-roller Geobiastes squamigerus in Madagascar. Ostrich. 75(1-2): 25-31. Close ) with short runs of 6–10 steps and foraging bouts, during which investigates logs and rummages through deep leaf litter with its bill to capture animals. Perches up to 10 m high, occasionally flying short distances, or hawks flies and butterflies over short distances in air. Possibly active also at twilight and at night.

Territorial call, given only in Sept–Jan (1 Safford, R. J., and A. F. A. Hawkins, Editors (2013). The Birds of Africa. Volume 8. The Malagasy Region. Christopher Helm, London, UK. Close ), a series of soft, hollow “whoo-oop ” or more modulated “mowooop” (1 Safford, R. J., and A. F. A. Hawkins, Editors (2013). The Birds of Africa. Volume 8. The Malagasy Region. Christopher Helm, London, UK. Close ) notes each lasting c. 1 second (1 Safford, R. J., and A. F. A. Hawkins, Editors (2013). The Birds of Africa. Volume 8. The Malagasy Region. Christopher Helm, London, UK. Close ) and inflected slightly upwards, higher-pitched than B. leptosomus, repeated every 5–30 seconds, delivered from perch 0·1–5 m high during early morning (especially around dawn) (1 Safford, R. J., and A. F. A. Hawkins, Editors (2013). The Birds of Africa. Volume 8. The Malagasy Region. Christopher Helm, London, UK. Close ) and late afternoon, in bouts of up to 22 minutes; contact call single “whoop”, lower and longer than territorial call; brief, muffled “ko-uh” during foraging; alarm a dry, churr and a sharp, harsh hiss, latter similar to that of Madagascar Wood-rail (Mentocrex kioloides); harsh grating as threat; also harsh excited “kwek” notes after prey capture; and when alarmed, brief trilled “frrret”, sharp, raspy, hissing “kwish-sh” decreasing in volume, or soft, quiet, growling hiss.

Season Sept–Jan (laying mid-Oct–early Nov in one study) (2 Rakotoarisoa, J.E. and Be, B. (2004). Breeding and foraging behaviour and habitat characteristics of the Scaly Ground-roller Geobiastes squamigerus in Madagascar. Ostrich. 75(1-2): 25-31. Close ); some pairs may not breed every year. Probably monogamous and territorial (1 Safford, R. J., and A. F. A. Hawkins, Editors (2013). The Birds of Africa. Volume 8. The Malagasy Region. Christopher Helm, London, UK. Close ). Nests in areas of unusually high herb cover and three nests discovered recently were all near streams in valleys (2 Rakotoarisoa, J.E. and Be, B. (2004). Breeding and foraging behaviour and habitat characteristics of the Scaly Ground-roller Geobiastes squamigerus in Madagascar. Ostrich. 75(1-2): 25-31. Close ). Excavates in sloping earth bank, burrow 0·5–1 m long with diameter 6·5–10 cm (2 Rakotoarisoa, J.E. and Be, B. (2004). Breeding and foraging behaviour and habitat characteristics of the Scaly Ground-roller Geobiastes squamigerus in Madagascar. Ostrich. 75(1-2): 25-31. Close ), ending in nest-chamber c. 20 cm wide and 15 cm high, lined in one instance with dead leaves and earthy pellets; recorded to co-inhabit burrow system with tuft-tailed rat (Eliurus webbi). Two active nests belonging to different pairs were placed 230 m apart, while the same pair built nests within 50 m of each other in consecutive seasons (2 Rakotoarisoa, J.E. and Be, B. (2004). Breeding and foraging behaviour and habitat characteristics of the Scaly Ground-roller Geobiastes squamigerus in Madagascar. Ostrich. 75(1-2): 25-31. Close ). Clutch usually one whitish (2 Rakotoarisoa, J.E. and Be, B. (2004). Breeding and foraging behaviour and habitat characteristics of the Scaly Ground-roller Geobiastes squamigerus in Madagascar. Ostrich. 75(1-2): 25-31. Close ) egg, sometimes two, c. 55 mm × 30 mm (2 Rakotoarisoa, J.E. and Be, B. (2004). Breeding and foraging behaviour and habitat characteristics of the Scaly Ground-roller Geobiastes squamigerus in Madagascar. Ostrich. 75(1-2): 25-31. Close ); only female incubates (provisioned by male) (1 Safford, R. J., and A. F. A. Hawkins, Editors (2013). The Birds of Africa. Volume 8. The Malagasy Region. Christopher Helm, London, UK. Close ), for at least 18 days, and broods chicks (2 Rakotoarisoa, J.E. and Be, B. (2004). Breeding and foraging behaviour and habitat characteristics of the Scaly Ground-roller Geobiastes squamigerus in Madagascar. Ostrich. 75(1-2): 25-31. Close ); both parents put equal effort into feeding chick, which comes to entrance to take food, with a mean 12 items (range 9–20) fed to a single chick in a nest per day (2 Rakotoarisoa, J.E. and Be, B. (2004). Breeding and foraging behaviour and habitat characteristics of the Scaly Ground-roller Geobiastes squamigerus in Madagascar. Ostrich. 75(1-2): 25-31. Close ); fledging period c. 24 days (2 Rakotoarisoa, J.E. and Be, B. (2004). Breeding and foraging behaviour and habitat characteristics of the Scaly Ground-roller Geobiastes squamigerus in Madagascar. Ostrich. 75(1-2): 25-31. Close ). Once chick fledges (when tail not yet fully grown) (3 Raveloson, B. and Safford, R. (2012). Photospot: Juvenile Scaly Ground-roller Geobiastes squamiger. Bull. African Bird Club. 19(1): 79-80. Close ), adults cover, fill and hide nest entrance with dead leaves and sticks (2 Rakotoarisoa, J.E. and Be, B. (2004). Breeding and foraging behaviour and habitat characteristics of the Scaly Ground-roller Geobiastes squamigerus in Madagascar. Ostrich. 75(1-2): 25-31. Close ). Female remains constantly with young for first week post-fledgling, whereas male leaves group for periods of 15–40 minutes, while parental care appears to cease when juvenile is 60 days of age (2 Rakotoarisoa, J.E. and Be, B. (2004). Breeding and foraging behaviour and habitat characteristics of the Scaly Ground-roller Geobiastes squamigerus in Madagascar. Ostrich. 75(1-2): 25-31. Close ).

VULNERABLE. Overall population estimated at 1500–7000 mature individuals within range of 21,300 km². Restricted-range species: present in East Malagasy Wet Forests EBA. Uncommon, but easily overlooked, and may be more common than previously believed; in Masoala National Park up to eight pairs have been located in c. 100 ha (2 Rakotoarisoa, J.E. and Be, B. (2004). Breeding and foraging behaviour and habitat characteristics of the Scaly Ground-roller Geobiastes squamigerus in Madagascar. Ostrich. 75(1-2): 25-31. Close ). Occurs in at least 16 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); substantial part of an important lowland site, Masoala Peninsula, recently became a National Park. Most serious threat is rapid habitat destruction, as most of the lowland rainforest of coastal plain already cleared or highly degraded by slash-and-burn agriculture, with commercial logging an additional threat in some areas; if present trends continue, remaining unprotected forest, especially at lower altitudes where this species more abundant, will disappear within decades. However, recent incidental observations of species from tavy (cleared areas for swidden agriculture) and second growth, might mean that G. squamiger is not restricted to primary forest (2 Rakotoarisoa, J.E. and Be, B. (2004). Breeding and foraging behaviour and habitat characteristics of the Scaly Ground-roller Geobiastes squamigerus in Madagascar. Ostrich. 75(1-2): 25-31. Close ). Is also hunted by humans and introduced dogs.