Red-shouldered hawk (Buteo lineatus) COSEWIC assessment and status reportchapter 6

Distribution

Global Range

The eastern and central North American breeding population ranges west through southern Canada from southern New Brunswick, southern Quebec and southern Ontario to the eastern edge of the United States Great Plains, south to Florida, the Gulf states and eastern Mexico (Crocoll 1994; Figure 1). In western North America, a disjunct population breeds west of the Sierra Nevada from northern California to northern Baja, California. Breeding records are known from suitable habitat throughout this range. The wintering range of the Red-shouldered Hawk includes southern Wisconsin, Oklahoma, southern Ohio and southern New England south to the Gulf Coast (Figure 1). In winter, Red-shouldered Hawks are most common in southern Texas, Florida and the Mississippi Valley (National Audubon Society 2002). The lineatus subspecies breeds from eastern Oklahoma, central Arkansas, Tennessee and northern South Carolina, north to New Brunswick, southern Quebec, south-central Ontario, northern Michigan, northern Wisconsin and central Minnesota. This subspecies is typically a short-distance migrant and is occasionally found wintering within its Canadian breeding range.

The present distribution of the Red-shouldered Hawk is similar to its historic distribution in North America. In some northern regions, however, it has become locally extirpated, or has extended its range northward. In the last few decades, it has declined in southern Michigan, but extended its range to the northern part of the state (Michigan Department of Natural Resources 1980; Postupalsky 1980). A similar range expansion has occurred in Minnesota (Minnesota Department of Natural Resources 1975), and in Ontario (Ontario Breeding Bird Atlas, Red-shouldered Hawk and Spring Woodpecker Survey unpublished data).

 

Canadian Range

In Canada, the Red-shouldered Hawk occurs in Ontario, Quebec and New Brunswick, with the majority of the population in Ontario (Figure 1). In Ontario, most breeding records for Red-shouldered Hawks are from the Great Lakes Forest Region, and a few additional breeding sites have been identified in the Carolinian and Southern Boreal forests (2nd Ontario Breeding Bird Atlas unpublished data; Figure 2). Ontario Breeding Bird Atlas data show that the distribution of the Red-shouldered Hawk in Ontario has changed very little over the past 20 years (Figure 2). However, there appears to be a small increase in the number of locations in the northern extent of the species’ range.

In Quebec, the species’ breeding range is restricted to maple grove forests. It is sparsely distributed within appropriate habitat in the following regions: Montérégie, Montréal, south of the Laurentians in the Outaouais region, Bois-Francs and in the western part of the Eastern Townships (Morneau and Dionne 1997; Figure 3). The Red-shouldered Hawk is uncommon in New Brunswick, and found in scattered locations throughout the western and southern parts of the province. The Red-shouldered Hawk is reported from British Columbia, but records have not been verified (Campbell et al. 1990).


Figure 1: Distribution of the Red-shouldered Hawk, lineatus Subspecies, in North America

Figure 1. Distribution of the Red-shouldered Hawk, lineatus subspecies, in North America.

Breeding range, wintering range and year-round range are shown. Data provided by NatureServe in collaboration with Robert Ridgely, James Zook, The Nature Conservancy - Migratory Bird Program, Conservation International - CABS, World Wildlife Fund - US and Environment Canada – WILDSPACE.

One percent of the Red-Shouldered Hawk’s breeding population is in Canada based on BBS data from 1984–2003 (P. Blancher pers. comm.). Based on the range map (Figure 1), the extent of occurrence (EO) for the Red-shouldered Hawk in Canada is 200 000 km2. Within this range, approximately 40% of the area is forested, which suggests that the maximum area of occupancy (AO) is 80 000 km2. This estimate of AO should be considered a maximum because not all forested area provides suitable breeding habitat (see Habitat requirements).


Figure 2: Distribution of the Red-shouldered Hawk in Ontario According to the First (1981-1985) Ontario Breeding Bird Atlas and the First Four Years of the Second (2001-2004) Ontario Breeding Bird Atlas

Figure 2. Distribution of the Red-shouldered Hawk in Ontario according to the first (1981-1985) Ontario Breeding Bird Atlas and the first four years of the second (2001-2004) Ontario Breeding Bird Atlas.

Data from the second atlas should be considered preliminary.


Figure 3: Distribution of the Red-shouldered Hawk in Quebec, Based on Data from the Quebec Breeding Bird Atlas (1984-1989)

Figure 3.  Distribution of the Red-shouldered Hawk in Quebec, based on data from the Quebec Breeding Bird Atlas (1984-1989).

 

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