Whistling Heron

The Whistling Heron, Syrigma sibilatrix, presents itself as a medium-sized heron, unique in its genus, with a distinctive appearance that sets it apart from its relatives. It is adorned with a palette of blue-gray, gold, and buff, with variations in plumage between the two subspecies, the southern S. s. sibilatrix and the northern S. s. fostersmithi.

Identification Tips

Adults of this species boast a blue-gray upper body contrasted by white rear parts visible in flight. The southern subspecies is characterized by a black crown and cinnamon-colored wing coverts, while the northern subspecies displays a slate-gray crown and honey-colored wing coverts. The bill is a striking pink with a blue to violet base and a black tip, and the legs are a subtle greenish hue. Around the eye, one can observe a notable patch of bare bluish skin.

Habitat

The Whistling Heron favors seasonally flooded savannas and grassy terrains, often drier than those preferred by other herons. It is also comfortable in human-altered landscapes such as pastures and roadsides, and it has a penchant for perching on fenceposts.

Distribution

The subspecies S. s. fostersmithi is found in the Llanos and the Orinoco basin of Colombia and Venezuela, while S. s. sibilatrix inhabits areas from eastern Bolivia to northeastern Argentina, including parts of Paraguay, western and southern Brazil, Uruguay, and Chile. It is known to make seasonal movements in some regions.

Behaviour

This heron exhibits solitary or paired feeding habits, occasionally joining larger groups. It employs a variety of hunting techniques, from standing still to actively chasing prey. It is also known to feed in close proximity to humans.

Song & Calls

The Whistling Heron is named for its melodious whistle, a "kee, kee, kee" sound that carries far and wide. It also emits a drawn-out whistle upon taking flight and a harsh alarm call when disturbed.

Breeding

Courtship involves aerial displays of gliding and circling. Unlike most herons, the Whistling Heron nests solitarily, often in trees. The eggs are pale blue and speckled, with a clutch size of three to four. Post-fledging care is provided by the parents, a behavior not commonly seen in heron species.

Similar Species

The Whistling Heron can be distinguished from other herons by its unique coloration, calls, and non-retracted neck during flight.

Diet and Feeding

Its diet consists of small animals found in dryland and marshes, and it has been observed pirating food from other species. It is adept at catching flying insects, particularly dragonflies.

Conservation status

The Whistling Heron is currently classified as Least Concern by the IUCN, benefiting from certain human activities such as deforestation and agriculture.