Humblot's heron (''Ardea humbloti''), also known as the Madagascar heron, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

heron Herons are long-legged, long-necked, freshwater and coastal birds in the family Ardeidae, with 75 recognised species, some of which are referred to as egrets or bitterns rather than herons. Members of the genus ''Botaurus'' are referred to as bi ...

. It is commonly found on the north and west coasts of

Madagascar Madagascar, officially the Republic of Madagascar, is an island country that includes the island of Madagascar and numerous smaller peripheral islands. Lying off the southeastern coast of Africa, it is the world's List of islands by area, f ...

but it is also present in the

Comoro Islands The Comoro Islands are a group of volcanic islands in the Mozambique Channel, an arm of the Indian Ocean lying between Madagascar and the African mainland. Three of the islands form the Union of the Comoros, a sovereign nation, while Mayotte bel ...

and

Mayotte Mayotte ( ; , ; , ; , ), officially the Department of Mayotte (), is an Overseas France, overseas Overseas departments and regions of France, department and region and single territorial collectivity of France. It is one of the Overseas departm ...

. Humblot's heron is considered an

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

due to its declining population. The major threats the heron faces are

poaching Poaching is the illegal hunting or capturing of wild animals, usually associated with land use rights. Poaching was once performed by impoverished peasants for subsistence purposes and to supplement meager diets. It was set against the huntin ...

habitat destruction Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...

, and the invasion of alien species such as the

water hyacinth ''Pontederia crassipes'' (formerly ''Eichhornia crassipes''), commonly known as common water hyacinth, is an aquatic plant native to South America, naturalized throughout the world, and often invasive species, invasive outside its native rang ...

Taxonomy

Humblot's heron is part of the subfamily

Ardeinae Ardeinae is a subfamily of herons, which includes the day herons, night herons, and egrets. Taxonomy Extant Genera Fossils * Genus ''Proardea'' (fossil) * Genus ''Zeltornis'' (fossil, Early Miocene of Djebel Zelten, Libya) * Genus undetermin ...

, which are known as "typical herons". It has been suggested that Humblot's heron may be a darker morph of the

grey heron The grey heron (''Ardea cinerea'') is a long-legged wading bird of the heron family, Ardeidae, native throughout temperate Europe and Asia, and also parts of Africa. It is resident in much of its range, but some populations from the more norther ...

due to their many similar physical characteristics, but this claim has been successfully refuted. Humblot's heron was formally described by

Henri Milne-Edwards Henri Milne-Edwards (23 October 1800 – 29 July 1885) was a French zoologist. Biography Henri Milne-Edwards was the 27th child of William Edwards, an English planter and colonel of the militia in Jamaica and Elisabeth Vaux, a Frenchwoman. Hen ...

and

Alfred Grandidier Alfred Grandidier (20 December 1836 – 13 September 1921) was a French natural history, naturalist and List of explorers, explorer. From a very wealthy family, at the age of 20, he and his brother, Ernest Grandidier (1833–1912), undertook a ...

in 1885. Local Malagasy names for Humblot's heron include "Kisirano", "Langaro" and "Langaroko", however these names are also associated with different species of herons, such as the grey heron. The scientific name commemorates the

French French may refer to: * Something of, from, or related to France ** French language, which originated in France ** French people, a nation and ethnic group ** French cuisine, cooking traditions and practices Arts and media * The French (band), ...

naturalist Leon Humblot.

Description

Humblot's heron has a uniform dark gray plumage on its body and darker feathers on its forehead and chin. Its nape feathers are elongated to form a crest. It has a large, pale bill as well as pale eyes and legs. Humblot's heron is tall. Its body weight can range between . The bill length ranges from while the bill depth ranges from .

Distribution and habitat

Humblot's heron is endemic to the island of Madagascar and is most commonly found in the coastal lowlands of southern, western and northern Madagascar. Small populations have also been found in the neighboring islands of Comoros and Mayotte. There has been one recorded and accepted observation of the heron in mainland Africa, in a game reserve in Tanzania. The total population of Humblot's heron in Madagascar was estimated in 2006 at 1,000 to 3,000 individuals. Ardea humbloti map

Humblot's heron inhabits fresh, brackish or saltwater wetlands. It prefers tidal areas but also inhabits lakes, rivers, mangroves and estuaries. It is found most commonly at low elevations but has been recorded up to an altitude of . It does not migrate, however it is able to disperse over long distances, as shown by its presence in mainland Africa.

Behavior

Diet

Humblot's heron primarily eats medium and large-sized fish as well as crustaceans. They forage on floating vegetation in clear, shallow water or in the ingoing and outgoing tides. They are passive feeders, therefore they remain stationary for long periods of time, often hunched or with their neck extended over the water. After catching their prey, they will fly to solid ground to consume it.

Reproduction

Little information is known about its breeding cycle. Nesting has been observed year-round. Nests are typically on the ground and surrounded by dense aquatic vegetation. They can also be found in trees between tall. In Mayotte, the heron was observed nesting in mangroves. The Humblot's heron's nest is mostly made of sticks and reeds and is approximately in diameter. Their eggs are blue and the typical clutch size is 3 eggs. Both parents take turns incubating the eggs.

Vocalizations

Its vocalizations are similar to the vocalizations of the grey heron. It is an irregular barking sound that lasts 0.5-1.0 s. Humblot's heron is also known to rattle its bill quietly while in its nest.

Conservation status

Humblot's heron is considered endangered, per the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological ...

. Its population is declining most likely due to poaching, both of the eggs and of the bird. Additionally, due to the increasing human population in Western Madagascar, the wetlands where the heron nests are being transformed more and more into rice paddies. The increasingly drier climate is also contributing to the degradation of their preferred nesting habitats. The rate at which its population is decreasing has not yet been established.

References

External links

BirdLife Species Factsheet.Range map of ''Ardea humbloti''Audio recordings of ''Ardea humbloti'' vocalizations
Humblot's heron Humblot's heron Birds of the Comoros Birds of Madagascar Humblot's heron {{Pelecaniformes-stub