Scaly Ground-Roller
Geobiastes squamiger
Chunky, long-legged, intricately patterned bird. Pale blue tail tips are conspicuous in flight. Elusive and uncommon; unlikely to be seen by those not searching for it. Found at low and middle elevations in eastern rainforest. Feeds in the understory, avoiding disturbance by fleeing on the ground. Song is a long “bwooooop” note that is repeated slowly, delivered from a low perch.
Taxonomy
This species taxon has been referred to by several other synonymous names until recently, including the following binomial names:<p>Until the 2000s, the taxon was called Brachypteracias squamigera, in the genus Brachypteracias. The scaly ground roller, Geobiastes squamiger, is in the monotypic genus Geobiastes, however was originally placed in the genus Brachypteracias in 1838 by Frédéric de Lafresnaye. The species was moved to Geobiastes to reflect its unclear phylogenetic relationship with the sister taxon to its family Brachypteraciidae, Brachypteracias leptosomus. The scaly ground roller also has a different tarsometatarsus to hallux measurement ratio compared to the genera Brachypteracias, Uratelornis, and Atelornis, where the scaly ground roller has a smaller ratio (2.8) compared to the other genera (4.5). An enlarged tarsometatarsus may be a derived character in the family Brachypteraciidae.
- Scientific name
- Geobiastes squamiger
- Authority
- (Lafresnaye, 1838)
- Order
- Passeriformes
- Family
- Turdidae
- Genus
- Geobiastes
Range and habitat
- Migration
- Resident species
Behavior
The diet of the scaly ground roller mostly consists of invertebrates it collects from the ground but it does also eat vertebrates it can find. It has been reported to chiefly eat earthworms (Pheretima sp.) and centipedes (Scolopendra morsitons), but spiders, frogs, lizards (Zonosaurus sp. and Phelsuma sp.), and tenrecs (Microgale sp.) have also been reported to be eaten by the ground roller.<p>Nesting occurs in small burrows, ranging from 6.5 to 10 cm (2.6–3.9 in) wide and 55 to 77 cm (22–30 in) deep. The nests are generally found near sources of water and where there's great herbaceous ground coverage. The scaly ground roller lays its eggs from mid-October to early November, with a clutch size of one egg. Incubation is conducted solely by the female for a period of 18 days. During brooding, the female generally will remain with the egg while a male brings food to the nest. Both parents provide food for their young after hatching.
Conservation
The scaly ground roller is threatened by habitat loss and is considered by IUCN to be a vulnerable species. Although threatened by removal of its ecological niche, it is more resilient to climate change and forest conversion effects than other similar species. Climate change can result in further loss of its habitat. It may also face risks from human hunters and domesticated dogs.
- Population trend
- declining
Photos
Distribution
Bird Calls
Other Birds
East Coast Akalat
Sheppardia gunningi
Variable small robin-like skulker of the forest floor and mid-story. Upperparts are rusty-brown and underparts are buff-apricot to rufous (varying in intensity); some populations have a white belly and throat. Broad eyebrow is blue-gray with a white spot above the lores. Pairs can be common but inconspicuous in lowland primary and secondary forest, preferring the understory, but when vocal it sits calling from mid-canopy. Song a sweet rolling repeated “tuwuyu-teelu”. Does not overlap with other akalats in range or habitat choice.
Crested Ant-Tanager
Driophlox cristata
Unmistakable; dull red tanager with grayer flanks and obvious bright red crest. Sexes similar; males have longer crest. Found in pairs or small flocks in the understory, often in dense thickets or vine tangles. Sometimes follows mixed-species flocks. Uncommon in foothills in western Colombia.
Henderson Island Fruit-Dove
Ptilinopus insularis
Relatively subdued in coloration for a fruit-dove. Has a dusky gray chest and face, a yellow eye-ring, a magenta forehead patch, and mostly green wings and body. An adaptable species found at all elevations. Shares its range with no similar species. Call is typically a long series of “woot” notes, well spaced and gradually descending in pitch.
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