Northern Prairie Wildlife Research Center
Status: Regular migrant and nesting species.
Migration: Abundant migrant in all regions. Spring migrants arrive in the Western Upland 25 March to 5 April and reach the Northern Highland 5-10 April. Peak spring abundance occurs 20-30 April. Fall migration begins in late July with flocking of family groups. Peak fall abundance occurs 15-30 August and departure by 10 October. During peak fall migration, tree swallows are occasionally observed in massive mixed-species flocks near large water bodies. Concentrations of 4,000 to 5,000 individuals are frequently observed along the lower St. Croix River.
Nesting Season Distribution: Common nesting species in the Western Upland and Central Plain, common and more local in the Northern Highland. Breeding Bird Survey data (Table 3) show that tree swallows are uniformly distributed throughout the Valley.
Habitat: Tree swallows nest in loose, semicolonial associations. Breeding pairs are typically associated with water bodies that are normally near small groves of trees (Western Upland and Central Plain) or along northern Forest Bordered Lakes. Extensive use is made of the edge between deciduous forest and natural openings or agricultural fields. Nests are normally located in natural cavities in tree stumps or fence posts and occasionally in holes in stream banks. Tree swallows have benefited by exploiting the large number of eastern bluebird houses that have been placed in agricultural areas near residential areas.
Status: Regular migrant and nesting species.
Migration: Common spring and fall migrant throughout the Valley. Spring migrants arrive in the Western Upland 15- 20 April and reach the Northern Highland 20-25 April. Peak abundance occurs between 25 April and 15 May. Fall migration begins during mid-July. Peak abundance through the Valley occurs between 25 July and 5 August, and departure by 5 September.
Nesting Season Distribution: Common nesting species throughout the Western Upland and Central Plain becoming uncommon to rare and local in the Northern Highland. Breeding Bird Survey data (Table 3) show that the breeding distribution of this swallow is restricted primarily to areas that are not heavily forested.
Habitat: Breeding bank swallows are associated with natural banks along rivers, streams, and lakes. Gravel pits and roadside banks that were exposed during highway construction are also heavily used. Colonies are frequently associated with open agricultural areas that are used extensively for foraging.
Status: Regular migrant and nesting species.
Migration: Common migrant in the Western Upland and Central Plain, north to Grantsburg, Burnett County; rare and local elsewhere. Spring migrants arrive 15-25 April and peak abundance occurs 25 April to 5 May. Fall migration begins in late July with gathering of family groups. Peak abundance occurs between 25 July and 10 August and departure by 1 September.
Nesting Season Distribution: Fairly common (locally abundant) breeding species in the Western Upland and Central Plain, rare to absent in heavily forested regions. Breeding Bird Survey data suggest that this species is the least common of the swallows nesting in the Valley. However, Goddard (1972) found rough-winged swallows among the 10 most abundant breeding bird species along the Kinnickinnic River, Pierce County. Average breeding density in that area was 26.5 pairs per 40 ha. This exceptionally high density results from the numerous exposed limestone cliffs along that river, which provide abundant nesting sites.
Habitat: Breeding rough-winged swallows are usually associated with exposed banks along rivers and streams. Particularly important are limestone cliffs along fast-moving streams and rivers in the Western Upland. Occasional use is made of artificial earthen banks and bridges over small streams.
Status: Regular migrant and nesting species.
Migration: Common spring and fall migrant throughout the Valley. Spring migrants arrive in the Western Upland during 15-20 April reaching the Northern Highland about 25 April (earliest-11 April 1953, Burnett County}. Peak abundance during spring migration occurs 5-10 May. Fall migration begins about 1 August. Peak fall abundance occurs 25 August to 10 September and departure by 10-15 October.
Nesting Season Distribution: Common nesting species in the Western Upland and Central Plain, uncommon and local in the Northern Highland. Breeding Bird Survey data (Table 3) suggest that the barn swallow is the most numerous breeding swallow in the Western Upland and Central Plain.
Habitat: Primarily a species of open habitats, usually associated with human habitation. Most nests are found under bridges or on buildings.
Status: Regular migrant and nesting species.
Migration: Common migrant throughout the Valley, occasionally abundant near the St. Croix River. Spring migrants arrive in the Western Upland 1-5 May and peak abundance occurs 10-20 May. Fall migration begins in mid-August. Peak fall abundance occurs 1-10 September and departure by 25 September (latest-18 October 1974, Pierce County).
Nesting Season Distribution: Fairly common breeding species throughout the Valley. Breeding Bird Survey data (Table 3) suggest that the abundance of the nesting population increases northward across the Valley.
Habitat: Primarily a colonial or semicolonial nesting species, utilizing barns, sheds, and bridges extensively for nest placement. Occasional groups are found nesting in natural settings, including limestone cliffs.
Status: Regular migrant and nesting species.
Migration: Common to abundant migrant throughout the Valley. Spring migrants arrive 5-10 April and peak abundance occurs 1-10 May. Fall migration begins about 1 August. Peak abundance occurs 25 August to 1 September and departure by 20 September (latest-6 October 1966, Washington County).
Nesting Season Distribution: Common nesting species throughout the Valley. Jackson (1942) referred to the purple martin as "the most generally distributed" among the swallows in northwestern Wisconsin. Breeding Bird Survey data (Table 3) suggest that the largest densities occur in the Central Plain.
Habitat: The purple martin is one of few species benefiting from expanding human population. Colonial martin houses in residential and rural areas have become vitally important to this species.