[order] CICONIIFORMES | [family] Ciconiidae | [latin] Mycteria ibis | [authority] Linnaeus, 1766 | [UK] Yellow-billed Stork | [FR] Tantale ibis | [DE] Nimmersatt | [ES] Tantalo Africano | [NL] Afrikaanse Nimmerzat
Mycteria is a genus of large tropical storks with representatives in the Americas, east Africa and southern and southeastern Asia. Two species have “ibis” in their scientific or old common names, but they are not related to these birds and simply look more similar to an ibis than do other storks. The Mycteria storks are large birds, typically around 90?100 cm in length with a 150 cm wingspan. The body plumage is mainly white in all the species, with black in the flight feathers of the wings. The Old World species have a bright yellow bill, red or yellow bare facial skin and red legs, but these parts are much duller in the Wood Stork of tropical America. Juvenile birds are a duller version of the adult, generally browner, and with a paler bill. They are broad-winged soaring birds that fly with the neck outstretched and legs extended. They are resident breeders in lowland wetlands with trees in which build large stick nests.
Two prehistoric relatives of the Wood Stork have been described from fossils. 1) Mycteria milleri (Miller’s Stork) (Valentine Middle Miocene of Cherry County, USA) – formerly Dissourodes. 2) Mycteria wetmorei (Wetmore’s Stork) (Late Pleistocene of W and SE USA, and Cuba)
The latter seems to have been a larger sister species of the Wood Stork, which it replaced in prehistoric North America. Late Miocene tarsometatarsus fragments (Ituzaingo Formation at Parana, Argentina) are somewhat similar to Mycteria but still distinct enough to be probably a distinct genus, especially considering their age. A Late Pleistocene distal radius from San Josecito Cavern (Mexico) may belong in this genus or in Ciconia. A “ciconiiform” fossil fragment from the Touro Passo Formation found at Arroio Touro Passo (Rio Grande do Sul, Brazil) might be of the living species M. americana; it is at most of Late Pleistocene age, a few 10.000s of years.
Adult male yellow-billed storks have a smooth forehead and their face is orangey-red. Their bills are long and thick at the base. It is also slightly curved at the tip and bright yellow, hence their name. Their necks are also long and slender and grayish white. The rest of their body including their back, belly and breast is solid white with a small hint of pink on the tips of their feathers. Their tail and wing quills are black The yellow-billed storks legs vary from a dark red to a light pink color and are long and skinny. Its hard to believe that their legs can support their plump, round bodies. The female storks are alot like the male storks, however the females are smaller.
Listen to the sound of Yellow-billed Stork
Copyright remark: Most sounds derived from xeno-canto
Africa : widespread. The African Openbill is found in Africa, South of the Sahara, but it is infrequent throughout West Africa.
It also occurs in Madagascar, mainly on the western regions.
The species inhabits a variety of wetlands with shallow water 10-40 cm deep for feeding and sandbanks or trees for roosting. It frequents large swamps, the margins of rivers and lakes, lagoons, large marshes, small pools, flooded grassland, alkaline lakes, reservoirs, waterholes and rice-paddies, less commonly foraging on marine mudflats, in tidal pools along beaches or in estuaries. The species generally avoids areas of large-scale flooding and is rare in forested areas (although it may occur in wooded savanna.
Breeding is seasonal and starts whenever food is most abundant according to local ecological conditions (e.g. when fish become concentrated in small wetlands or marshes), this may either be towards the end of the rains or during the dry season. The species breeds colonially, often with other species. The nest is constructed of sticks and is positioned in small trees over water or high up in larger trees on dry land (e.g. Accacia spp., Bombax spp. or baobabs). The species nests colonially in single- or mixed-species groups with up to 10-20 pairs per tree (occasionally up to 50 pairs), neighbouring nests usually spaced 1-3 m apart. Once the female has laid her eggs (normally 2-3 eggs) the incubation period is about 30 days long. The eggs are laid on alternate days, so they also hatch accordingly. The young remain in the nest for up to 55 days when the fledging period begins. The stork comes of breeding age at around 3 years old. The lifespan of a stork is about 19 years in captivity.
Its diet consists of small aquatic prey such as frogs, small fish1, aquatic insects, worms, crustaceans and occasionally small mammals and birds
Video Yellow-billed Stork
copyright: Josep del Hoyo
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). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very 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.
The yellow-billed storks have remarkable adaptation. These birds are know to have the quickest muscular reflex of the neck, allowing almost all food to be caught in the water. Their long, narrow, curve tipped bills allow them only to catch small prey such as small fish, frogs, insects and worms passing by in the water. Yellow-billed storks are intelligent birds. These birds created a technique to help them catch more prey in the water. They typically use one foot to stir up the water or mud which disturbs and flushes out the prey. Then they submerge their heads quickly in the water snapping their bills on small prey. Yellow-billed storks bills are great fishing tools.
This species makes irregular migratory, partially migratory or nomadic movements within Africa to areas where changing water levels increase fish availability. Some populations are also largely sedentary.