Bare-throated Tiger Heron (Tigrisoma mexicanum)

Bare-throated Tiger Heron

[order] CICONIIFORMES | [family] Ardeidae | [latin] Tigrisoma mexicanum | [authority] Swainson, 1834 | [UK] Bare-throated Tiger Heron | [FR] Onore du Mexique | [DE] Nacktkehl-Reiher | [ES] Avetigre Mejicana | [NL] Mexicaanse Tijgerroerdomp

Subspecies

Monotypic species

Genus

The genus Tigrisoma consists of 4 Heron species native to South and Central America. These birds are rather large and typically forest dwellers. Their plumage is rich in coloration and adapted to boreal life.

Physical charateristics

The throat is bare and is greenish-yellow to orange in all plumages. The adult has black crown and light grey sides of head, the sides of the neck and the upperparts otherwise blackish narrowly barred buff. The median stripe down the foreneck is white bordered with black; the remaining underparts are dull cinnamon brown. The juvenile is buff coarsely barred with black, more mottled and vermiculated on wings; the throat, median underparts and belly are whitish.

Listen to the sound of Bare-throated Tiger Heron

[audio:http://www.planetofbirds.com/MASTER/CICONIIFORMES/Ardeidae/sounds/Bare-throated Tiger Heron.mp3]

Copyright remark: Most sounds derived from xeno-canto


wingspan min.: 0 cm wingspan max.: 0 cm
size min.: 71 cm size max.: 81 cm
incubation min.: 0 days incubation max.: 0 days
fledging min.: 0 days fledging max.: 0 days
broods: 1   eggs min.: 1  
      eggs max.: 3  

Range

Latin America : Mexico to Colombia. In Mexico, it occurs as far north as south Tamaulipas and south Sonora, along both coasts, across the Isthmus of Tehuantepec, in all of the Yucatan, coastal in Central America through Panama, including Coida Island and Perles Archipelago but of limited distribution on the Caribbean slope, into extreme north west Colombia from Gulf of Uraba’ to the lower Atrato River valley.

Habitat

The Bare-throated Tiger Heron is a bird of tropical swamps. Along the coast, it is typically a mangrove species. It is found, however, in a variety of coastal and freshwater situations, typically characterized as forest edged aquatic habitats. It feeds in coastal lagoons, mangrove swamps, fresh water marshes, swamps, gallery forests along rivers and streams, and wet meadows. It feeds more in the open and in larger habitats than other tiger herons. It is primarily a coastal species occurring below 1000 m. It avoids human habitats.

Reproduction

The breeding season is variable. In Costa Rica nesting may be year round but peaks at the early rainy season. It is May-August in most of its range but February-April in Panama. The tiger heron nests solitarily in trees above the water, especially in mangroves (Rhizophora). Nests are small to large platforms made of sticks usually lined with leaves. They are placed on branches 4-15 m above the ground. Courtship is little understood in this species, and the displays reported have little context to them. The primary display appears to be a version of the Stretch – a pair faced each other, necks and bodies crouched horizontally, feathers fluffed up; the birds raise their bills and neck vertically, depressing the neck and body feathers, and emitting two or three hoarse booms or roars. They may sway the neck at the vertical. This may be repeated, and one bird may move toward the other. Clutch size is 1-3 eggs, incubation and fledging period not yet recorded.

Feeding habits

The primary foraging behavior of this cryptic heron is Standing in shallow water or on the edge of the water, with neck stretched out diagonally, waiting motionless for long periods. It also Walks slowly, often in situations away from cover. It is a solitary species, usually foraging alone. However a dozen have been seen in a loose group when food is readily available. It is primarily crepuscular but also partially nocturnal. When disturbed it takes flight and perches in a nearby tree. It eats fish, frogs, crabs, and flies.

Video Bare-throated Tiger Heron

httpv://www.youtube.com/watch?v=xldpwW9Bheo

copyright: Max Roth


Conservation

This species has a very 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 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 bare throat of this species was recognized for years as being highly distinctive. It is now placed in the same genus as the other two South American tiger herons. The tiger herons are a distinctive lineage of the Ardeidae, adapted to a forest existence. The five species constitute a sister group to all the other herons and bitterns and to the Boat Billed Heron
Bare-throated Tiger Heron status Least Concern

Migration

Sedentary throughout range

Distribution map

Bare-throated Tiger Heron distribution range map

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