The Nelson's sparrow, Ammospiza nelsoni, presents itself as a small, unassuming New World sparrow. Its plumage is a subtle blend of earthy tones, with a distinctive orange cast gracing its face, complemented by gray cheeks. The crown and nape are washed in gray, while the breast is cream-colored with faint streaking. A white throat and belly, along with a short, pointed tail, complete its modest attire.
When attempting to identify the Nelson's sparrow, look for its orange face and the gray cap that adorns its head. Its compact body measures between 11 to 13 centimeters in length, and it tips the scales at a mere 17 to 21 grams. The wingspan is modest, stretching from 16.5 to 20 centimeters. The bird's understated streaking and pointed tail are also key characteristics to note.
The Nelson's sparrow favors the marshy realms for its breeding grounds. These are typically found along the Atlantic coast of Canada and Maine, within the central Canadian Prairies, and along a coastal strip south of Hudson Bay, as well as in the north-central United States.
This sparrow is a migratory bird, retreating to the southeastern coast of the United States when the breeding season concludes. Its movements are dictated by the seasons, ensuring it resides within suitable climes throughout the year.
The Nelson's sparrow is known for its ground foraging habits, often venturing into marsh vegetation and sometimes probing the mud in search of sustenance. Its diet is a mix of insects, aquatic invertebrates, and seeds. During the nesting season, its call—a raspy trill reminiscent of a drop of water sizzling on a hot pan—may be heard, sometimes even in flight.
Breeding season for the Nelson's sparrow is a time of promiscuity, with males vying for the attention of females without the establishment of territories. It is not uncommon for multiple paternities to occur within a single nest. The nests themselves are open cups, attached to vegetation and positioned close to the ground, making them susceptible to habitat loss and the perils of rising sea levels.
The IUCN Red List currently categorizes the Nelson's sparrow as Least Concern. However, its low-lying nesting habits make it vulnerable to environmental changes, particularly those associated with climate change, such as rising sea levels.