In Ohio, at the eastern edge of their breeding range, population fluctuations are quite noticeable. Breeding dickcissels return to Ohio during the last half of May and early June. Most nests are constructed in June and most young fledge in July and early August. Dickcissels spread eastward from the Great Plains during the nineteenth century, and became established in Ohio during the mid-1800s.
Little data exist on the vegetative characteristics of dickcissel nesting territories.
Nests are built on or near the ground, either in clumps of herbaceous vegetation or in crotches of woody vegetation. Forbs appear to be preferred over grasses as nesting substrate. George et al. A higher volume of vegetation in old fields permitted higher nesting densities and a greater forb component increased food availability compared to tallgrass prairie. They noted that dickcissels nested successfully only in the taller vegetation provided on unmowed waterways.