USGS Home
Contact USGS
Search USGS

Platte River Status: A common migrant and nesting species from Dawson County west; uncommon and local in the east. Tout (1947) considered black-headed grosbeak a common summer resident in Lincoln County, present 3 May to 15 September. Rosche (1979) found this species only twice (in May and August) in the lower North Platte River Valley.

Breeding Range: A common nesting species on the Western Plain and in the Platte River Valley west of Dawson County. Fairly common and locally distributed along the Platte River east to Merrick County. Uncommon and local in the Sandhills and on the Eastern Plain. Black-headed grosbeak is particularly common in the canyonland of the Dissected Plain in southern Lincoln County. Short (1961) found black-headed grosbeak along the Platte River east to Grand Island; hybrid grosbeaks were found west to Gothenburg, Dawson County.

Breeding Population: The population was estimated at 5,480 breeding pairs in 1979-1980. Black-headed grosbeak made up 0.2% of the total bird population in the study area those years.

Habitat: We found the highest mean breeding densities in lowland forest (1.7 pairs/km²), followed by river channel island (0.2 pairs/km²). Black-headed grosbeak occurs most commonly in mature lowland forest supporting large cottonwood trees and an open shrub layer. Faanes (1983a) associated highest breeding densities of black-headed grosbeaks in western North Dakota with forests of open canopy, low shrub density, and high basal area density of forest trees. Rising (1974) found this species commonly in mixed deciduous woodlands in western Kansas.

Effect of Habitat Alteration: Black-headed grosbeak has benefited from the establishment of forest vegetation within the channels of the Platte River system. The apparent selection of forests with open shrub layer vegetation suggests that moderate intensity livestock grazing in riparian vegetation may not be detrimental to this species.

Nesting Data: Tout (1947) found eight black-headed grosbeak nests in Lincoln County between 17 May and 17 June; mean clutch size was 3.7 eggs. Lingle observed a rose-breasted grosbeak x black-headed grosbeak hybrid in Hall County (T. 9 N.-R. 11 W.) on 10 July 1983. Hudson (1933) described a hybrid "almost intermediate" between rose-breasted and black-headed grosbeak collected 28 June 1930 near Grand Island, Hall County (ZM 07076), and another hybrid male taken near Inland, Clay County, 24 May 1923. Most western Kansas egg dates are during late May and early June (Rising 1974). Johnsgard (1979) reported Kansas egg dates from 11 May to 10 July.