Rufescent tiger heron

Taxonomy

When he first described the rufescent tiger heron in 1783, based on a specimen collected in Cayenne, French Guiana, Pieter Boddaert named it Ardea lineata. In 1827, William John Swainson moved the species to his newly created genus Tigrisoma; it is now one of three species in that genus. The rufescent tiger heron has two subspecies:

The genus name Tigrisoma is a combination of two Greek words: tigris, meaning "tiger" and somā, meaning "body".

Description

The rufescent tiger heron is a medium-sized heron, measuring 26–30 in (66–76 cm) in length, with a mass between 630 and 980 g (22 and 35 oz). The sexes are similarly plumaged. The adult's head, neck and chest are dark rufous, with a white stripe down the center of the foreneck. The remainder of its upperparts are brownish with fine black vermiculations, its belly and vent are buffy-brown, and its flanks are barred black and white. Its tail is black, narrowly barred with white. Its stout bill is yellowish to dusky, and its legs are dull green. Its irides, loral skin and orbital ring are bright yellow. Unlike other tiger herons, it has no powder down feathers on its back.

The juvenile bird is rusty-buff overall, coarsely barred with black; the buff and black banding on its wings is especially pronounced. Its throat, central chest and belly are white. It takes some five years to acquire adult plumage.

Similar species

The adult rufescent tiger heron is relatively easy to distinguish from fasciated and bare-throated tiger herons, as it is rufous (rather than primarily gray) on the head and neck. Young birds, however, are much more difficult to identify.

Distribution and habitat

The rufescent tiger heron is found in wetlands from Central America through much of South America. It generally occurs below 500 m (1,600 ft), though it has been recorded as high as 1,600 m (5,200 ft) in Colombia.

Behavior

It is largely crepuscular and generally solitary.

Food and feeding

As might be expected of a species that spends most of its time by the water, much of the rufescent tiger heron's diet is aquatic-based, including fish, crustaceans, water beetles and dragonfly larvae. It also takes adult dragonflies and grasshoppers. It typically hunts alone, standing hunched in shallow pools or wet areas of forest while it waits for prey.

Voice

The rufescent tiger heron's main call is a low-pitched paired hoot, often given at night. It also gives a fast series of sharp wok notes, which decrease in volume and speed, and a prolonged hoot, transcribed as ooooooo-ooh which rises markedly at the end.

Conservation

Although the rufescent tiger heron's population size and trend has not been quantified, its range is huge, so the International Union for the Conservation of Nature lists it as a species of least concern.