Status and Occurrence of Great-tailed Grackle (Quiscalus mexicanus) in British Columbia. Submitted: April 15, 2017.
By Rick Toochin.
Read the full article with photos here.
Introduction and Distribution
The Great-tailed Grackle (Quiscalus mexicanus) is a very large blackbird that has been rapidly expanding its breeding range in North America since the early 1900’s, when it was restricted to
southern Texas (Johnson and Peer 2001). Since that time the Great-tailed Grackle’s breeding range has exploded northward to be found as a year round resident from southern California,
east through southern Nevada, south-western Utah, across Arizona, New Mexico, Texas, Oklahoma, north into eastern Kansas, south eastern Nebraska, western Missouri, south into
western Arkansas and Louisiana (Johnson and Peer 2001). The Great-tailed Grackle is found as a breeding species north of the permanent range in parts of Northern California, eastern Oregon,
northern Nevada, Utah, Colorado, western Kansas, north into Nebraska, with its population extending north into Iowa (Sibley 2000, Dunn and Alderfer 2011).
The Great-tailed Grackle was considered conspecific with the Boat-tailed Grackle (Quiscalus
major) until it was officially split into 2 species by the American Ornithological Union in 1973 (Eisenmann et al. 1973). While the Boat-tailed Grackle breeds in open marsh in coastal areas, the Great-tailed Grackle prefers drier coastal habitats and is typically found in areas with scattered trees near standing water (Johnson and Peer 2001). It nests high in large trees, as well
as in marsh vegetation. Inland, the Great-tailed Grackle is more frequently found in prairies, agricultural areas, and towns, while the Boat-tailed Grackle is more likely to nest in marshy
areas (Johnson and Peer 2001). The Common Grackle (Quiscalus quiscula) occurs in many of the same habitats as the Great-tailed Grackle, including marshes and cities, but uses open woodland and forest edge more readily (Johnson and Peer 2001).
The Great-tailed Grackle forages in open, grassy areas such as grasslands, pastures, and lawns. It is well adapted to lawns, trees, and dumpsters in cities (Sibley 2000, Johnson and Peer 2001).
Its diet is varied and includes arthropods, small vertebrates, plant matter, and garbage (Johnson and Peer 2001). Although there is considerable overlap in the distribution of the 3 species, the
Common Grackle occurs throughout the eastern United States and Canada, the Great-tailed Grackle is found in the Midwest and western United States, and the Boat-tailed Grackle is confined to Florida and coastal areas of the Gulf States and the eastern United States (Johnson and Peer 2001, Dunn and Alderfer 2011). Like the Great-tailed Grackle, the Common Grackle expanded its range to the west during the twentieth century (Johnson and Peer 2001).
The Great-tailed Grackle is a permanent resident south of North America, and is found throughout Mexico, south through Central America, and even into South America (Ridgely and Gwynne 1989, Stiles and Skutch 1989, Howell and Web 2010). There are eight recognized subspecies, with 3 found in North America (Johnson and Peer 2001).
As the Great-tailed Grackle continues to expand northward records are likely to increase in regions well north of the species’ current breeding range (Sibley 2000, Johnson and Peer 2001).
The Great-tailed Grackle has been found as a vagrant along most of the Eastern United States and in many states north of its normal range in the Great Plains (Sibley 2000, Dunn and Alderfer 2011). In Canada, the Great-tailed Grackle has been found as an accidental vagrant with 1 record for Nova Scotia (Johnson and Peer 2001, McLaren 2012), at least 3 records for Ontario (Weir 1988, Weir 1989, Currie 2004), 1 record for Manitoba (Swick 2013) and 2 records for Alberta (Johnson and Peer 2001).
In the Pacific Northwest, the Great-tailed Grackle is an accidental vagrant with 10 accepted records for Washington State by the Washington Bird Records Committee (WBRC 2016). In
British Columbia, the Great-tailed Grackle is also classified as an accidental vagrant with 5 provincial records (Toochin et al. 2014). There are no records for Alaska (Gibson et al. 2013), however there is a record of unknown origin for Hawaii (Ralph and Pyle 1982).
Please refer to the PDF of the article to read more.
