Pelecaniformes Order – Ardeidae Family
Length: 50-61 cm
Weight: 520-545 g
Whistling Heron is a beautiful heron, probably the most colourful of the Ardeidae.
Fr : Héron flûte-du-soleil
All : Pfeifreiher
Esp : Garza Chiflona
Esp : (Argentine): Chiflón
Esp : (Bolivia): Chiflón
Esp : (Colombia): Garza Silbadora
Esp : (Paraguay): Garza silbadora
Esp : (Uruguay): Chiflón
Ital: Airone fischiatore
Port : Maria-faceira
Philippe Wolfer : OISEAUX D’ARGENTINE
Eduardo Andrés Jordan : MIS AVES – AVES DE ARGENTINA
Text by Nicole Bouglouan
HANDBOOK OF THE BIRDS OF THE WORLD vol 1 by Josep del Hoyo-Andrew Elliot-Jordi Sargatal - Lynx Edicions - ISBN: 8487334105
THE HERON HANDBOOK by James Hancock and James Kushlan- CROOM HELM – IBSN: 0709937164
On the upperparts, it has pale bluish-grey back, wings and tail. On the upperwing, median and lesser coverts are cinnamon, finely streaked black on lesser coverts. Rump is pale yellow.
On the underparts, lower breast, belly and flanks are pale yellow. Body sides and undertail are white. On the underwing, flight feathers are dark grey and coverts are pale yellow.
The neck is straw-coloured from head base to upper back and breast.
The head pattern is conspicuous. The crown is dark grey to black, ending in curved, long, rigid black feathers on the upper nape. Lores are blue, as the eye-ring. The area situated below the ear-coverts is pinkish-cinnamon. Chin is whitish.
The straight, long bill is pinkish to red, with black tip. Eyes are very pale, yellow or grey. Legs and feet are blackish to greenish-black.
Head pattern is duller outside the breeding season.
Both sexes are similar.
Immature is greyer and duller than adults. We can see fine streaks on neck and lesser wing-coverts. The head pattern is dull, with greyish lores and pale pink bill with blackish tip. Legs are paler too.
We find two subspecies:
S.s. sibilatrix is the southern race, found from Bolivia to SE Brazil and NE Argentina.
S.s. forstersmithi is the northern race, found in E Colombia and Venezuela. This one is smaller, but with longer bill.
VOICE: SOUNDS BY XENO-CANTO
Whistling Heron’s typical call is a whistle given in flight. It is a far-carrying “kee-kee-kee”. It also utters a flute-like “kleeer-er”, often repeated twice or in series. This sound gives the bird its name.
When threatened, it gives a harsh “quah-h-h” call.
Whistling Heron is more terrestrial than other Ardeidae. It is often found along the roads and perched on fences. Of course, this species also frequents wet areas, shallow water in marshes, rice fields, flooded woodlands and edges of streams.
In some parts of the range like in Uruguay, Whistling Heron feeds in dry fields. In Bolivia, it frequents the marshy open areas situated between the tropical forests and the drier deciduous woodlands. In Argentina, it is often found in marshy areas with scattered trees and around ponds.
Whistling Heron is a South American species found in the northern and southern regions separated by the Amazon Basin.
Whistling Heron is diurnal and territorial when feeding. It usually forages in pairs, but groups of up to 25 birds can be observed.
As other herons, it stands up motionless, waiting for prey. It also walks slowly on the shore or in shallow water, or runs with head and neck low.
Preys are caught by bill thrust or by pecking at food on wet soils. It also gleans from vegetation.
Whistling Heron spends the night at large roosts in trees, where they arrive in the evening, about one hour before dark. Flocks of 100-200 herons can be seen.
Some displays are observed at feeding areas, when the heron strongly defends its territory. They walk, weave, jab at and call to each other.
When the breeding season begins, plumage and head pattern become brighter. The long black crest feathers are raised during the displays. Both mates fly back and forth and circle while gliding.
Whistling Heron is sedentary, performing only local movements according to the weather conditions.
The northern populations may migrate, being absent from NE Venezuela from November to January.
Breeding season varies according to the range.
Whistling Heron usually nests solitary, but scattered colonies may be found sometimes.
The nest is situated in tree, on thick branch. It is made with twigs forming a platform, at about 3 to 11 metres above the ground. It is a flimsy structure without any lining.
Female lays 3-4 pale blue eggs, speckled at the ends.
Nesting period is poorly known, but incubation probably lasts about one month, and fledging period one month more.
Both parents feed the young even after leaving the nest, and usually only two young fledge.
Whistling Heron flies with rapid wing-beats and neck less retracted than other herons.
Whistling Heron feeds mainly on earthworms, amphibians, dragonfly larvae, flying insects, fish, eels, lizards and aquatic snakes.
PROTECTION/ THREATS/ STATUS:
Whistling Heron is locally common but patchily distributed.
The species is not threatened at this moment.