The range expansion of the great‐tailed grackle (Quiscalus mexicanus Gmelin) in North America since 1880

Abstract

Aims This study aimed to document and describe the current range expansion of the great-tailed grackle (Quiscalus mexicanus Gmelin) into the USA. By examining the habitat associations and pattern of spread of this species, I intended to determine the factors responsible for this remarkable expansion by a tropical species into a temperate environment.Location This study focused on the spread of the great-tailed grackle in the continental USA, Canada and Baja California.Methods I used published records, museum specimens, and egg collections to document this range expansion from 1880 through 2002. In addition I surveyed large portions of Arizona, Nevada, southern Utah and southern California for great-tailed grackles during 2000 and 2001. The data gathered was used to create maps in order to quantify the rate of spread of this species.Results Between 1880 and 2000 the great-tailed grackle expanded its breeding range in the USA from c. 64,000 km 2 to more than 3,561,000 km 2 , an increase of 5530%. The average annual rate of increase is 3.4%, but has lessened during the past 20 years. Northward movement in the eastern portion of the range has slowed down, reflecting this decrease. However, in the central and western portion of the species range, the rate of northward movement is still accelerating. During this expansion, the average time between first sighting in a state and first breeding was 5.8 years. The species has become less migratory during its range expansion, wintering in 17 of the 20 states where it breeds.Main conclusions This range expansion has been marked by great-tailed grackles preferring human-modified environments as breeding grounds, especially in the western states. This association appears to benefit the species in two ways; nest predation is lessened in such areas compared with natural conditions, whereas human activities tend to generate an abundant and consistent food supply for feeding offspring. Wintering birds are often associated with cattle feed lots and large-scale dairies, where abundant waste grain provides them with a reliable food supply. Given the continued human population increase throughout large areas of the western USA, the great-tailed grackle will continue its range expansion.

Ecology and Ethnobiology of the Slender-billed Grackle Quiscalus palustris

“…And if this were true, it would not be surprising, since all of its congeners seem to prosper and increase with some forms of urban and agricultural development (Jaramillo and Burke 1999;Wehtje 2003). Furthermore, the bird seems to have evolved on the Mesa Central and lived in sympatry there with various pre-Hispanic human cultures for thousands of years, and so may have had ample time to adapt as civilization gradually evolved in the Mesoamerican Highlands.…”

“…This clade, which corresponds to the subspecies nelsoni and graysoni, is found west of the Sierra Madre Occidental, from Sinaloa northwards (Powell et al 2008) and has, in the past century, colonized parts of Arizona, California and Baja California (Wehtje 2003).…”

Rare Feeding Behavior of Great-Tailed Grackles (Quiscalus mexicanus) in the Extreme Habitat of Death Valley~!2010-01-08~!2010-03-08~!2010-05-21~!

“…The Great-tailed Grackle is a large icterid, whose range has been expanding rapidly in large-scale north and west in North America in recent years [1][2][3][4][5][6][7][8]. It reached California along the Colorado River in 1964 [9].…”

Observaciones generales de la dieta del zanate mexicano Quiscalus mexicanus en Puerto Vallarta, México

“…org/10.28947/hrmo.2018.19.1.311 El zanate mexicano Quiscalus mexicanus es originario de la vertiente del Golfo de México y actualmente se encuentra distribuido en todo el país (Christensen 2000, Gurrola-Hidalgo et al 2009); además, se ha registrado en Hawái, Canadá, Estados Unidos de América, Centroamérica y el Caribe, así como Venezuela, Colombia, Ecuador y Perú en Sudamérica (aou 1998). Su amplia dispersión se debe principalmente a la adaptabilidad y tolerancia a los ambientes modificados por las comunidades humanas (Wethje 2003, Gurrola-Hidalgo et al 2009). et al (2009), además de mencionar que el zanate mexicano es una especie oportunista, también indican que ingiere una gran variedad de presas de vertebrados, invertebrados, crustáceos pequeños y otros animales marinos, además de granos y frutos.…”