[2] Gmelin based his account on the "black throated bunting" which the Welsh naturalist Thomas Pennant had described and illustrated in 1785 in his Arctic Zoology.

Though the color pattern and habits of the dickcissel make it stand apart from other Cardinalidae, its robust, cone-shaped bill – stouter than in American sparrows or true finches, which it somewhat resembles at first glance – gives away its relationships.

This individual was collected on May 11, 1833, by Audubon's colleague John Kirk Townsend in New Garden Township, Chester County, Pennsylvania.

The specimen has foxed today, giving it an altogether beige hue, but when originally shot, the olive areas of the head were grey as the cheeks, and the yellow and buff on face and underside was pure white.

While only a complete molecular biological study of the dickcissel's metabolism and the specimen's ancient DNA stands any reasonable chance to resolve the question with certainty, the hypothesis of an extremely uncommon color mutation is plausible, and such phenomena certainly occur in other Passeroidea.

Regardless, Townsend observed the bird making vocalizations reminiscent more of an indigo bunting (Passerina cyanea), and by comparing mitochondrial and nuclear DNA sequences of the specimen with those of the dickcissel, the indigo bunting, and perhaps other Passerina, the hybridization hypothesis should be far more easy to prove or reject than a color aberration.

On the other hand, not enough is known on whether dickcissels pick up their characteristic vocalizations from conspecific males or whether they are innate, thus no firm conclusion regarding Townsend's observations has been made.

[13] Dickcissels have a large, pale bill, a yellow line over the eyes, brownish upperparts with black streaks on the back, dark wings, a rust patch on the shoulders, and light underparts.

From 1966 to 2015 the dickcissel experienced a greater than 1.5% population reduction in the northern part of its breeding range and throughout the Midwestern United States.

[16][17] They nest near the ground in dense grasses or small shrubs, or up to 3–4 ft (91–122 cm) high in bushes and trees.