Usage examples for hackles:

• The whole upper parts of this bird, its fine coronal crest of erectile plumes, its shoulder- hackles or long lance- shaped feathers, that droop over the sides, and the elongated tail- coverts which hang down beyond the tail to a length of three feet or more, curving elegantly under the bird, as it sits on a branch, are of the richest golden green, shining with a satiny radiance. "The Romance of Natural History, Second Series" – Philip Henry Gosse

• His hackles rose as he thought of a senseless plunge into unplumbed distance. "Comet's Burial" – Raymond Zinke Gallun