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COSEWIC Assessment and Update Status Report on the Cerulean Warbler in Canada


Global Range

The Cerulean Warbler breeds mainly from north-central Minnesota, northern Wisconsin, the central Lower Peninsula of Michigan, southern Ontario, New York, and western Vermont, south through Massachusetts, Connecticut, New Jersey, Pennsylvania, northern Delaware, West Virginia, North Carolina, and northern Georgia, and west to central Arkansas, Missouri and Iowa. Local breeding has also been recorded in the north (southeastern Quebec), south (northern Mississippi) and west (eastern Oklahoma, Kansas and Nebraska) (Figure 2; Dunn and Garret 1997; Hamel 2000a; Rosenberg et al. 2000). The Cerulean Warbler is not uniformly distributed throughout this range with notable concentrations in the Cumberland Mountains of Tennessee, the Montezuma Wetlands complex in New York, southern Illinois, southeastern Ontario, and West Virginia. Casual records exist in North America in both Canada (Manitoba, northern Ontario, New Brunswick, Newfoundland, Nova Scotia) and the United States (Arizona, California, Colorado, Nevada, New Hampshire, New Mexico, North Dakota).

Figure 2: Breeding Distribution of the Cerulean Warbler in North America

Figure 2: Breeding distribution of the Cerulean Warbler in North America (modified from Hamel 2000a).

Modified from Hamel 2000a.

The Cerulean Warbler winters in the Andes Mountains of South America (Figure 3). The range includes northern and western Venezuela, both slopes of the Andes in Columbia, and the eastern slope of the Andes in Ecuador, Peru, and Bolivia (Ridgley and Tudor 1989; Robbins et al. 1992). Extralimital sightings include 2 sightings from southeastern Brazil (Ridgely and Tudor 1989), occasional sightings from eastern Venezuela and the western slope of the Andes in Ecuador (Dunn and Garrett 1997) as well as winter sightings from the Grand Caymans, Costa Rica and Panama (Bent 1953; Hamel 2000a). This species tends to be restricted to elevations between 500 and 1500 m (Robbins et al. 1992).

The bulk of Cerulean Warbler migration (both spring and fall) appears to occur along the Mississippi and Ohio River valley (Hamel 2000a). This species generally migrates across the Gulf of Mexico and, to a lesser extent, along the Caribbean coast of Central America (Parker 1994; Howell and Webb 1995; Hamel 2000a). Fall records from Bermuda and the West Indes indicate that some of the population migrates through the Greater Antilles (Dunn and Garrett 1997).

Figure 3: Winter Distribution of the Cerulean Warbler in South America

Figure 3: Winter distribution of the Cerulean Warbler in South America (modified from Ridgley and Tudor 1989). Star represents extralimital sighting in southeastern Brazil.

Modified from Ridgley and Tudor 1989). Star represents extralimital sighting in southeastern Brazil.

Canadian Range

The Canadian breeding range for the Cerulean Warbler has not changed appreciably since McCracken’s 1993 initial COSEWIC status report. There still appear to be two main breeding geographic clusters in Ontario (in southern Ontario in Carolinian forests between lower Lake Huron and Lake Ontario, and a more northerly band between the Bruce Peninsula east to the Ottawa River with concentration on the Frontenac Axis at the east end of Lake Ontario). There is also a small number of breeding individuals in southeastern Quebec (Figure 4). Although incomplete, the current Ontario breeding bird atlas effort indicates that the two Ontario geographic clusters are still present (with some local extinctions and colonizations of sites). Records from the Banque de données sur les oiseaux menacés du Québec (BDOMQ; Shaffer pers. comm. 2002) indicate that singing males have been recorded in Quebec at 14 sites since 1965. However, only 8 of these sites have had more than one individual and breeding has only been confirmed at 6 of these 8 (Figure 4).

Figure 4: Current Breeding Distribution of the Cerulean Warbler in Canada

Figure 4: Current breeding distribution of the Cerulean Warbler in Canada.

Eagles 1987, McCracken 1993, Cyr and Larivée 1995 and the 2001-2 Ontario Breeding Bird Atlas.
Circles refer to detections during the 1st and 2nd (2001-2 only) Ontario Breeding Bird Atlas projects
(Closed circles = detected in both atlases;
open circles = detected in 1st atlas, not yet detected in 2nd;
bottom-filled circles = detected in 2nd atlas only).
Squares refer to Quebec locations
(open squares = detected only once;
top-filled squares = sightings in multiple years;
filled squares = breeding evidence).

Modified from Ouellet 1967.

Cerulean Warblers are very rarely caught at banding stations (e.g. 35 records from the Long Point Bird Observatory, 1967-2002, Francis pers. comm. 2002). The earliest documented arrival in Ontario is 18 April (Hamel 2000a) and 6 May in Quebec (David 1996). At one site in eastern Ontario (Queen’s University Biological Station), there appears to have been a shift towards earlier arrival over the last 8 years (13 May in 1994, 2 May in 2001; Jones et al. unpubl. data). Most adult birds have left Canadian breeding sites by late August.

Cerulean Warblers are considered accidental in Nova Scotia (17 records; Currie pers. com. 2002) and in New Brunswick (6 records; Christie pers. com. 2002), and rare in Newfoundland (7 records, Montevecchi pers. com. 2002). A single female found near Whitewater Lake, Manitoba, on 2 June 1924 represents the only confirmed record in Canada west of the Manitoba-Ontario border (Taylor pers. com. 2002).