| Malagasy sacred ibis | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Pelecaniformes |
| Family: | Threskiornithidae |
| Genus: | Threskiornis |
| Species: | T. bernieri |
| Binomial name | |
| Threskiornis bernieri (Bonaparte, 1855) | |
The Malagasy sacred ibis (Threskiornis bernieri) is a relatively large, heavily built ibis endemic to the west coast of Madagascar, and Aldabra on the Seychelles.
The Malagasy sacred ibis was formerly considered a subspecies of the African sacred ibis. [2] [3] It is now however classified as a separate species from the African sacred ibis due to considerable differences observed in the former’s ecology and morphology. [4] [5] It is hypothesized that the Malagasy sacred ibis evolved from the African sacred ibis when the latter supposedly spread to and colonized Madagascar from mainland Africa. [2]
There are two different subspecies of the Malagasy sacred ibis: Threskiornis bernieri bernieri (Bonaparte, 1855) on Madagascar, and T.b. abbotti (Ridgway, 1893) on Aldabra in the Seychelles. [6]
The adult stands 65–89 cm tall, [1] with a wingspan of 112–124 cm. [7] The plumage is predominantly white, often with brownish-yellow staining. There are also black ornamental plumes on the back with a blue or green gloss formed from the lower scapulars and tertials, which are most prominent in the breeding season. [7] The bill, head, neck and legs are black.
This ibis is morphologically similar to the African sacred ibis, but is slightly smaller, [3] more slender-billed, lacks the black trailing edge to the wings, has bluish-slate tertials (purplish-slate in the African sacred ibis), differently structured ornamental neck sacs, less developed ornamental plumes and a different display. [6] [3] [5] [8] Unlike the African sacred ibis, there is also little or no black on the wing tips and duller display plumes from the innermost secondaries. [2]
Both the bernieri and abbotti race have a light blue or white iris, both of which differ markedly from the brown iris of the African sacred ibis. [3] The abbotti race also has a black wing stripe. [3] Although this ibis is unlikely to be confused with other species in the field, it may sometimes be mistaken for the African sacred ibis which may occasionally visit Madagascar as a vagrant. [7]
The juvenile appears similar to the adult, but the head and neck are feathered black with white streaks, the ornamental plumes on the back are absent, and there may be some black on the wing tips. [7]
It is generally non-vocal, but the voice is probably similar to that of the African Sacred Ibis. [6]
Apart from its occurrence on Aldabra, the Malagasy sacred ibis is sparsely distributed along and restricted to the west coast of Madagascar, [5] especially between Port-Berge and Moromoe. [3] Although uncommon, some high densities of resident breeding populations have been observed in mangroves and estuaries near Soalala and Sahamalaza Bay and Baie de Baly; the region encompassed between these locations appears to be a species’ stronghold. [5]
The Malagasy sacred ibis is generally restricted to coastal mudflats, estuaries, mangrove swamps and shallow brackish coastal lakes; but is occasionally found on freshwater wetlands. [7] [1] It preferentially frequents wide, open pools without surrounding vegetation; as well as sand bars and sandy beaches for general resting places. [9] In one survey, over 80% of individuals recorded were found within 2 km of the coastline. [5] Its habitat is situated 0-150m above sea level. [7] [1] This species is considered more ecologically restricted than its mainland African counterpart, which is found in a wider range of habitats at a wider range of altitudes. [1]
The Malagasy sacred ibis feeds on crustaceans, diverse invertebrates, vegetable refuse [7] and more occasionally takes frogs, reptiles and young birds. [10] It forages mainly on mud in tidal areas, [5] thrusting its bill into the mud up to the eyes. [9] The abbotti race on the Seychelles feeds in coral pools and along lagoon shores (King, 1981 in Hancock). Feeding is often solitary, although some individuals have been observed foraging in pairs or threes. [5]
Egg-laying occurs at the beginning of the wet season in November and December. [9] [6] The clutch size is usually 2 eggs. [6] Average egg measurements for T.a. abbotti have been reported as 59.5mm long and 41.3mm broad and weighing 55g. [11]
This ibis nests colonially, sometimes with mixed heron species such as the Humblot's heron [12] or egret species such as cattle egret and dimorphic egret. [5] The nest lies 2-3m above the surface of the water in forks of Avicennia and Rhizophora trees and largely comprises twigs, some of which are still living with leaves attached. [9] The nest is structurally sturdy and measures 450-500mm across and 250mm deep. [9] Other nests have been reported to be smaller, measuring approximately 250mm across. [5]
The Madagascan population has been markedly declining mainly through unsustainable harvesting of eggs, nest site disturbance and wetland habitat degradation. [6] Human interference and habitat loss also pose threats to the abbotti race. [13] Because nesting individuals are apparently fearless of humans, this species is an easy target for hunters. [5] Habitat loss and degradation pose another serious threat to the population. Important areas of this species’ habitat are threatened with pollution, sedimentation and encroachment of alluvial sands. Such sedimentation is caused by soil erosion from slash and burn cultivation (Birdlife International, 2013). Its mangrove habitat is also threatened with destruction for charcoal production. [14] This ibis may further be in competition for food with egret species such as the dimorphic egret. [1]
Because this ibis has historically been widely considered conspecific with the African sacred ibis, no early separate conservation measures have been proposed for the former. [5] Coastal sites are generally poorly protected in western Madagascar, although new wetland conservation initiatives now include the species as a conservation target. [1] On the Seychelles, the Aldabra atoll has been designated a Special Reserve. [1]
This species has been popularly hunted and its eggs harvested for food by local villagers, and young nestlings have even been raised to serve as food for seasonal events. [5] This ibis is easily captured because of its passiveness and incautiousness when feeding and nesting. [5]
Two Malagasy sacred ibis individuals were once received by London Zoo from the Societe d’Acclimatation, Paris, in 1870. [15]
The Madagascan population size has been estimated at 1500-2000 mature individuals, [6] [5] and the population of the abbotti race on Aldabra has been estimated at 300-750 individuals, with a total estimated population of 2300-3250 individuals. [1] Its estimated global range is 25500 km2. [6] The species global’ population is estimated to have declined by over 20% over the last 16 years, most of which has probably occurred in recent decades. [1] The Malagasy sacred ibis has therefore been classified as Endangered by the IUCN and is generally considered rare throughout its range. [1] Historical accounts suggest that it was once commoner. [9]
The family Threskiornithidae includes 36 species of large wading birds. The family has been traditionally classified into two subfamilies, the ibises and the spoonbills; however recent genetic studies have cast doubt on this arrangement, and have found the spoonbills to be nested within the Old World ibises, and the New World ibises as an early offshoot.
The Australian white ibis is a wading bird of the ibis family, Threskiornithidae. It is widespread across much of Australia. It has a predominantly white plumage with a bare, black head, long downcurved bill and black legs. While it is closely related to the African sacred ibis, the Australian white ibis is a native Australian bird – contrary to urban myth, it is not a feral species introduced to Australia by people, and it does not come from Egypt.
The snowy egret is a small white heron. The genus name comes from Provençal French for the little egret, aigrette, which is a diminutive of aigron, 'heron'. The species name thula is the Araucano term for the black-necked swan, applied to this species in error by Chilean naturalist Juan Ignacio Molina in 1782.
The little egret is a species of small heron in the family Ardeidae. It is a white bird with a slender black beak, long black legs and, in the western race, yellow feet. As an aquatic bird, it feeds in shallow water and on land, consuming a variety of small creatures. It breeds colonially, often with other species of water birds, making a platform nest of sticks in a tree, bush or reed bed. A clutch of three to five bluish-green eggs is laid and incubated by both parents for about three weeks. The young fledge at about six weeks of age.
The cattle egret is a cosmopolitan species of heron found in the tropics, subtropics, and warm-temperate zones. It is the only member of the monotypic genus Bubulcus, although some authorities regard its two subspecies as full species, the western cattle egret and the eastern cattle egret. Despite the similarities in plumage to the egrets of the genus Egretta, it is more closely related to the herons of Ardea. Originally native to parts of Asia, Africa, and Europe, it has undergone a rapid expansion in its distribution and successfully colonised much of the rest of the world in the last century.
The black-headed ibis, also known as the Oriental white ibis, Indian white ibis, and black-necked ibis or colloquially as 'bin chicken', is a species of wading bird of the ibis family Threskiornithidae which breeds in the South and Southeast Asia from India to the west and as far east as Japan. It is the only native ibis species in its range that has an overall white plumage with a black neck and head. The down-curved beak and legs are also black. Though often referred to as a wetland species, the black-headed ibis forages in a range of natural and man-made habitats. This species of ibis nests only during the rainy season.
The roseate spoonbill is a gregarious wading bird of the ibis and spoonbill family, Threskiornithidae. It is a resident breeder in both South and North America. The roseate spoonbill's pink color is diet-derived, consisting of the carotenoid pigment canthaxanthin, like the American flamingo.
The African sacred ibis is a species of ibis, a wading bird of the family Threskiornithidae. It is native to much of Africa, as well as small parts of Iraq, Iran and Kuwait. It is especially known for its role in Ancient Egyptian religion, where it was linked to the god Thoth. The species is currently extirpated from Egypt.
This article is one of a series providing information about endemism among birds in the world's various zoogeographic zones. For an overview of this subject see Endemism in birds.
The Malagasy kestrel, also known as the Madagascar kestrel, Malagasy spotted kestrel, Newton's kestrel, Madagascar spotted kestrel, katiti (Creole) or hitsikitsika (Malagasy), is a small bird of prey of the genus Falco. It is named after British ornithologist Edward Newton. It occurs in two subspecies on Madagascar and at Aldabra. The race from Aldabra is also called Aldabra kestrel. Its closest living relative is the Seychelles kestrel; they were at one time considered conspecific. Their common ancestors appear to have diverged very recently, probably less than 1 million years ago during the Early or Middle Pleistocene. The Mauritius kestrel is more distantly related.(Groombridge et al. 2002)
The Seychelles white-eye is a rare warbler-like perching bird from the family of white-eyes (Zosteropidae). It is endemic to the Seychelles. At one time thought to be extinct, it was rediscovered and is now listed as Vulnerable by the IUCN.
The souimanga sunbird is a small passerine bird of the sunbird family, Nectariniidae. It is native to the islands of the western Indian Ocean where it occurs on Madagascar, the Aldabra Group and the Glorioso Islands.
The Malagasy pond heron, also known as the Madagascar pond heron or Madagascar squacco heron, is a species of heron of the family Ardeidae. They breed in Madagascar, Réunion and the Seychelles, and spend the non-breeding season in eastern mainland Africa. The population is estimated to number only 1,300–4,000 adults and the species is considered endangered.
The Madagascar plover, also known as the black-banded plover, is a small monogamous shorebird in the family Charadriidae, native to western Madagascar. It inhabits shores of lagoons, coastal grasslands, and breeds in salt marshes. These plovers mainly nest in open grassland and dry mudflats surrounding alkaline lakes. The species is classified as vulnerable by the IUCN because of its low breeding success, slow reproductive rate, and weak adaptation to increasing habitat loss, leading to declining population numbers.
The Malagasy coucal or Madagascar coucal is a species of cuckoo in the family Cuculidae. It is found in Madagascar and in the Seychelles, where it occurs on Aldabra and was formerly present on Assumption Island and Cosmoledo. Its natural habitats are dense vegetation in subtropical or tropical moist lowland forests, mangrove forests, rough grassland, marshes and reedbeds.
The Sakalava rail is a species of bird in the family Rallidae. It is endemic to western Madagascar. This bird is small with brown upperpart feathers, grey underparts, a yellow bill and red legs.
The Malagasy white-eye is a species of bird in the white-eye family, Zosteropidae. Found in Madagascar and Seychelles, its natural habitats are subtropical or tropical dry forests, subtropical or tropical moist lowland forests, subtropical or tropical mangrove forests, and subtropical or tropical moist montane forests.
The western cattle egret is a species of heron found in the tropics, subtropics and warm temperate zones. Most taxonomic authorities lump this species and the eastern cattle egret together, but some separate them. Despite the similarities in plumage to the egrets of the genus Egretta, it is more closely related to the herons of Ardea. Originally native to parts of Asia, Africa and Europe, it has undergone a rapid expansion in its distribution and successfully colonised much of the rest of the world in the last century.
Media related to Threskiornis bernieri at Wikimedia Commons
Data related to Threskiornis bernieri at Wikispecies
