Henslow's Sparrow (Ammodramus henslowii)

Status: State Threatened (1996).

Occurrence: Uncommon migrant south and central; rare migrant north. Uncommon summer resident south and central; rare summer resident north. Normal summer range covers about four-fifths of the state, with rare occurrences in northern counties. Not a common resident anywhere in state. A map outlining Pre-1977 and 1997 to Present Distribution is available.

Aid to ID: This small, short-tailed bird is about 5" in length. The head is flat, olive-colored and striped, the wings are reddish, and the bill is large and pale. Best identified by its song, a short, quiet "se-lick" accented on the second syllable.

Habitat: Undisturbed pastures and meadows, timothy hayfields, and uncultivated fields, generally preferring mesic or wet habitats with relatively tall and dense, but also somewhat sparse and patchy vegetation.

Food Habits: Primary food is insects; also eats spiders, and seeds of grasses and weeds. Young are fed only insects.

Natural History:

Breeding: Clutch size: 3-5 cream white eggs; laid from late April through late July. Incubation: 11 days. Fledging period: 9-10 days.
Nest: Deep cup of grasses, built at the base of a thick clump of grass; 2-3 inches off the ground. Nest in loose colonies or singly.

Management Considerations: The U.S. population of this uncommon and locally distributed species has declined more than 68% from 1966-1991. The Wisconsin population has also declined over that period, and it has dropped an average of 5% per year from 1982-1991. This species is a habitat specialist that has suffered from the loss of uncultivated fields with tall and dense vegetation. Henslow's sparrow ranked highest in the Wisconsin Grassland Bird Study's ranking of birds of management and conservation concern in the state. The control of woody vegetation is critical on public or idle lands, but this species will tolerate some woody vegetation. Also, because this species requires dense litter layers, it will benefit directly from management that promotes short burning rotations.