Great Blue Herons’ plumage patterns, especially along their long necks, are a form of ‘disruptive coloration’: Distinctive designs such as stripes and\or spots that break up the animal’s outline.
For some species this is more critical than ‘concealing coloration’ because they live in a variety of habitats with a variety of background colors making it impossible to always blend in with background colors. But often the habits have similar patterns within the surrounding landscapes such as grass\weeds, bank-side bushy, busy trees and branches, high weed & shrub growth, etc. Wetlands and bottom land swamps being great examples. Combined with different prey’s vision capabilities, or lack of such as forms color blindness, e.g., crusteans and many fish species, the Great Blue’s neutral blue-gray adds to their blending into a wide-variety of surroundings.
Add to this the ability to be completely motionless, except for moving their neck with the wind, Great Blue Herons can fade into the background as seen by a crayfish or frog looking up across the water’s surface boundary. Seeing just another clump of reeds, until it is too late.
