Dewlap Dewlap A dewlap is a longitudinal flap of skin that hangs beneath the lower jaw or neck of many vertebrates. While the term is usually used in this specific context, it can also be used to include other structures occurring in the same body area with a similar aspect, such as those caused by a double chin or the submandibular vocal sac of a frog. In a more general manner, the term refers to any pendulous mass of skin, such as a fold of loose skin on an elderly person's neck, or the wattle of a bird. Dewlaps can be
White-necked heron their young. Population explosions have been known when the environmental conditions are right for this species in places where they have been rare or unknown. Large water dwelling bird, diurnal animal. Slate-grey to black with distinctive black spots in the centre of the lower fore-neck and throat. During breeding season plum coloured nuptial plumes are present on the back and breast. Flight: stately, slow steady wing beats. Body size/length 76–106 cm, Wingspan 147–160 cm, Weight 860g.I have studied the bird, with many photos, estimate wingspan near 2m The bill is black and the facial skin is commonly blue or yellow.