Montana Field Guide

Lark Bunting - Calamospiza melanocorys

With their stark black bodies and white wing bars, Lark Buntings are a conspicuous resident of Montana's prairies. Their behavior also contributes to their visibility; males arrive earlier than females and set up colony-like territories so many individuals may be observed together during the breeding season. The Lark Bunting is one of six species of song birds endemic to the grasslands of North America.

Montana Range




Range Comments
The distribution of the species in Montana is primariy restricted east of the continental divide.

Lark Buntings may arrive in Montana as early as early May and stay through late August. The earliest nesting record for Montana is May 15th, the latest is August 10th.

Lark Buntings utilize short-grass and mixed-grass grass communities as well as fallow fields, roadsides, and hayfields.

The primary food source of this bunting is insects. Seeds are also consumed. While generally a ground gleaner, this species may also be observed hawking for insects.

The breeding behavior of this species is complicated and variable. While most pairs appear monogamous, polygyny has been documented, and polyandry is suspected.

Heavy grazing on short grasslands can negatively affect nesting Lark Buntings by decreasing food, shade, and nest site availability. Loss of habitat and measures to control insects, especially grasshoppers, can result in reduced nesting success. Managing for the species includes maintaining native grasslands, and tailoring grazing regimes to make suitable habitat for the species: implementing moderate grazing in taller grass and reducing or eliminating heavy grazing in arid, short-grass areas.

Destruction of native prairie in the east and northeast portions of their historic range has caused populations to disappear, while destruction of habitat elsewhere threaten existing nesting populations.