About the Whistling Heron
The whistling heron (Syrigma sibilatrix) is a medium-sized, often terrestrial heron of South America. It is the only species placed in the genus Syrigma. A molecular phylogenetic study published in 2023 found that within the heron family the whistling heron is most closely related to the capped heron (Pilherodius pileatus).
The whistling heron measures 53 to 64 cm in length and weighs 521 to 546 g. The southern subspecies is bigger but has a shorter bill in proportion to the body. The overall impression of standing birds is gray, with flying birds showing conspicuous white rear parts (lower back, belly, and tail). In both subspecies, adults' upperparts except the lower back are blue-gray. The feathers of the sides of head, sides of the neck, breast, and scapular area are basically white but are stained gold to buff, perhaps by the powder down typical of herons... Wikipedia →