[order] GRUIFORMES | [family] Rallidae | [latin] Amaurornis flavirostra | [UK] Black Crake | [FR] Rale a bec jaune | [DE] | [ES] Polluela Negra Africana | [NL] Zwart Porseleinhoen
Subspecies
Monotypic species
Physical charateristics
An all black marsh bird that has rounded wings, long, slender and red legs and toes, and a short thick yellow bill, small and elusive. Weight between 54-125 g, average around 86g. Wingspan about 25 cm.
Listen to the sound of Black Crake
[audio:http://www.aviflevoland.nl/sounddb/B/Black Crake.mp3]
Copyright remark: Most sounds derived from xeno-canto
| wingspan min.: | cm | wingspan max.: | cm | ||
| size min.: | 22 | cm | size max.: | 23 | cm |
| incubation min.: | 23 | days | incubation max.: | 19 | days |
| fledging min.: | 0 | days | fledging max.: | 19 | days |
| broods: | 1 | eggs min.: | 2 | ||
| eggs max.: | 4 |
Range
Africa : widespread
Habitat
The species inhabits many types of wetland, although it requires moderate vegetation cover, some degree of permanent flooding and tangled vegetation in which it can climb, roost and nest. Suitable habitats include flowing and still inland freshwaters (such as lakes, ponds, reservoirs, seasonal pans and temporary flooded areas along rivers), the margins of coastal lagoons (Ghana) and estuarine waters; preferably fringed by rank grass, sedges, reedbeds, papyrus, swampy thickets, bushes or other vegetation1. The species also inhabits ponds with floating submergent vegetation (e.g. water-lilies) and the interior of dense or extensive reedbeds, as well as dense undergrowth in boggy forest clearings, or the margins of swampy forest streams. In more open areas it may inhabit broad, grassy marshes and will occupy very small streams with little cover in drier regions.
Reproduction
The Black Crake is a monogamous bird laying between 2 to 6 white eggs. The nest is built on the ground with figs, straw and leaves and placed under a bush to protect the young from predators. Usually located above water as a means of protecting itself from predators and to be close to its main food source.
Feeding habits
The diet of this species consists of worms, molluscs, crustaceans, adult and larval insects, small fish, small frogs and tadpoles, the eggs and nestlings of weavers Ploceus spp. and herons (e.g. Rufous-bellied Heron Ardeola rufiventris), as well as the seeds and other parts of water plants (e.g. duckweed Lemna and water-lilies Nymphaea) and occasionally carrion.
Conservation
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend is not known, but the population is not believed to be decreasing sufficiently rapidly to approach the thresholds under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
This species is sedentary and a local migrant, its movements related to seasonal rainfall and the filling up of temporary waters. Young birds may also undergo extensive dispersal movements that are not linked to rainfall. The species may breed throughout the year when conditions are suitable, with seasonal peaks during or following periods of rain. It nests territorially, and is usually observed in pairs, but may gather in groups of up to 10 individuals. The adults may become flightless for up to 3 weeks between December and March when moulting their fight feathers, during which time they remain within the cover of waterside vegetation. The species is active diurnally, with peaks of activity occurring just after rainfall.
This species is sedentary and a local migrant, its movements related to seasonal rainfall and the filling up of temporary waters. Young birds may also undergo extensive dispersal movements that are not linked to rainfall. The species may breed throughout the year when conditions are suitable, with seasonal peaks during or following periods of rain. It nests territorially, and is usually observed in pairs, but may gather in groups of up to 10 individuals. The adults may become flightless for up to 3 weeks between December and March when moulting their fight feathers, during which time they remain within the cover of waterside vegetation. The species is active diurnally, with peaks of activity occurring just after rainfall.
Migration
Largely sedentary but also locally migratory. In drier N parts of range, in N Ghana, N Nigeria and Sahel zone of Sudan, appears with rains and disappears in dry season; moves in Zimbabwe when habitats dry out; occupies temporary waters in E Africa and NE Namibia; presumed migrant captured at night, Tsavo West (SE Kenya), in Dec. Seasonal variations in calling frequency, and in relative visibility of birds, may explain fluctuating reporting rates in other areas. Vagrant to Madeira, Jan 1895.
Distribution map
