Perception Channels: visual ; tactile ; acoustic ; chemical
Over the past 30 years the great-tailed grackle has expanded its range in the U.S. at a rate of greater than 2.5% annually. This expansion is due to human modification of the landscape. Irrigation in arid areas, urbanization, and increasing cropland have all contributed to this expansion of range.(Christensen 2000)
US Migratory Bird Act: no special status
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
The female of the species incubates the egg for 13-14 days. The chicks are born immobile, downless, with their eyes closed, and need to be fed by a parent. (Altricial development). The young leave the nest after a period of 20 to 23 days, and the female tends to them. (Sibley 2001).
Adult males are nearly granivorous (Jaramillo, 1999)
Negative Impacts: crop pest
May aid in agricultural pest control.
The great-tailed grackle is known to eat insects, lizards, aquatic invertebrates and vertebrates, fruit, grain, and grass seed (Sibley, 2001). They are also known to remove and eat ectoparasites from livestock. Male nestlings appear to require more food than females of the same age (Ehrlich et al., 1988).
Animal Foods: reptiles; fish; eggs; insects; terrestrial non-insect arthropods
Plant Foods: seeds, grains, and nuts; fruit
Primary Diet: omnivore
The great-tailed grackle, Quiscalus mexicanus, was historically almost exclusively found in South and Central America, but human alteration of the environment has caused the birds to expand their range to include parts of the United States and Canada (Christensen, 2000). Their current range in the United States is north to eastern Oregon, with individuals sighted as far north as Canada (Sauer et al., 1997), south to northwest Peru, and as far east as Western Arkansas (Jaramillo, 1999).
Biogeographic Regions: nearctic (Native ); neotropical (Native )
The great-tailed grackle is found in a variety of habitats, including groves, thickets, farms, towns, city parks, (Peterson, 1990), mangroves, and marshes (Jaramillo, 1999).
Habitat Regions: temperate ; tropical
Aquatic Biomes: coastal
Wetlands: marsh
Other Habitat Features: urban ; suburban ; agricultural ; riparian
A banded great-tailed grackle lived at least 12.5 years. (USGS, 2002)
Range lifespan
Status: wild: 12.5 (high) years.
Average lifespan
Status: wild: 150 months.
The male great-tailed grackle is a large blackbird that appears purple-glossed. He averages approximately 45 cm in length and has a long ample tail. A potential identification problem exists between the boat-tailed grackle and the great-tailed, but the tail of the great-tailed tends to be wider and longer. The female is brown with a pale breast, and averages 35 cm in length. Both sexes have distinctive yellow eyes as adults (Peterson, 1990).
Other Physical Features: endothermic ; bilateral symmetry
Early in the spring males establish small territories and begin the process of attracting females. The breeding is polygynous, and the females nest in the territory of one male. Several females will nest in a single male's territory, and mate with him. First year males are excluded from breeding but young females are not. The main display is the "ruff-out" which is accompanied by a song. In the "ruff-out" the tail is fanned while the body feathers are ruffed and the head is arched upwards as it sings. The wings are drooped and quivered or held out towards the sides. The male courtship display differs in that it is more exaggerated, the bill is pointed down rather than up, and the wings are rapidly quivered while the bird produces distinctive "cheat" notes. The female may respond by drooping and quivering the wings as the tail is cocked and gives "che" calls. (Jaramilo 1999)
Mating System: polygynous
First year males are excluded from mating, but young females (1 yr.) are not (Jaramillo, 1999). The breeding season begins in early April. Nesting occurs in colonies of few to thousands, with the nests placed close together. The males tend to avoid confrontation with low key disputes. The females will fight over the choice of nest sites, and will steal nest building materials from one another. Clutch sizes tend to average 3 to 4 eggs, and females incubate them for 13 to 15 days. The young are born altricial and leave the nest at 20 to 23 days (Harrison, 1978).
Breeding season: Spring
Range eggs per season: 3 to 4.
Range time to hatching: 13 to 15 days.
Range fledging age: 20 to 23 days.
Range age at sexual or reproductive maturity (female): 1 to 2 years.
Range age at sexual or reproductive maturity (male): 1 to 2 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Average eggs per season: 3.
Chicks are born immobile, downless, with their eyes closed, and need to be fed by a parent. The males do not participate in nesting or care of the young.
Parental Investment: altricial ; female parental care
The Great-tailed Grackle (Quiscalus mexicanus) is a large, noisy blackbird that is often seen in large groups, both when foraging and when gathering to roost overnight. These grackles are found in a wide range of semi-open and open habitats. They are resident from the southwestern and south-central United States and northern Baja California (present during the breeding season somewhat farther north) south to northern South America. This species has expanded its range northward in recent decades. Great-tailed Grackles forage mainly on the ground, feeding on a range of small arthropods, vertebrates, and other animals, as well as seeds, waste grain, and fruits. Great-tailed Grackles nest in colonies that may include anywhere from a few pairs to hundreds of pairs. Historically, this species and the Boat-tailed Grackle (Quiscalus major) were considered to be conspecific (i.e., members of the same species), but they were later found to co-exist without interbreeding from southwestern Louisiana to southeastern Texas (U.S.A.). (Kaufman 1996; AOU 1998)
The great-tailed grackle or Mexican grackle (Quiscalus mexicanus) is a medium-sized, highly social passerine bird native to North and South America. A member of the family Icteridae, it is one of 10 extant species of grackle and is closely related to the boat-tailed grackle and the extinct slender-billed grackle.[2] In the southern United States, it is sometimes simply referred to as "blackbird" or (erroneously) "crow"[3] due to its glossy black plumage, and similarly it is often called cuervo ("raven") in some parts of Mexico, although it is not a member of the crow genus Corvus, nor even of the family Corvidae.
Great-tailed grackles are medium-sized birds (larger than starlings and smaller than crows; 38 cm (15 in)-46 cm (18 in)) with males weighing 203 g (7.2 oz)-265 g (9.3 oz) and females between 115 g (4.1 oz)-142 g (5.0 oz), and both sexes have long tails.[4] Wingspan ranges from 18.9-22.8 in (48-58 cm).[5] Males are iridescent black with a purple-blue sheen on the feathers of the head and upper body, while females are brown with darker wings and tail.[4] Adults of both sexes have bright yellow eyes, while juveniles of both sexes have brown eyes and brown plumage like females (except for streaks on the breast).[4] Great-tailed grackles, particularly the adult males, have a keel-shaped tail that they can fold vertically by aligning the two halves.[6]
The great-tailed grackle and boat-tailed grackle were considered the same species until genetic analyses distinguished them as two separate species.[7]
Great-tailed grackles have an unusually large repertoire of vocalizations that are used year-round. The sounds range from "sweet, tinkling notes" to a "rusty gate hinge".[8] Males use a wider variety of vocalization types, while females engage mostly in "chatter", however there is a report of a female performing the "territorial song".[4] Because of their loud vocalizations, great-tailed grackles are considered a pest species by some.[9]
The great-tailed grackle mating season usually begins in early or mid-April. The nest is typically built near the top of a large or medium-sized tree, using materials such as woven grass and twigs, as well as some man-made materials. Females usually lay around 4 to 7 eggs. Incubation is usually around 14 to 13 days and their young usually leave the nest 12 to 17 days after hatching; the parents continue to feed their young several weeks after they have left the nest until they reach maturity.[10][11] Eggs are bright blue to pale bluish gray in color, marked with swirls and splotches that range from dark brown to black.[12]
Great-tailed grackles originated from the tropical lowlands of Central and South America, but historical evidence from Bernardino de Sahagún shows that the Aztecs, during the time of the emperor Ahuitzotl, introduced the great-tailed grackle from their homeland in the Mexican Gulf Coast to the Aztec capital of Tenochtitlan in the highland Valley of Mexico, most likely to use their iridescent feathers for decoration.[13] In more recent times, great-tailed grackles expanded their breeding range by over 5,500% by moving north into North America between 1880 and 2000, following urban and agricultural corridors.[14][15] Their current range stretches from northwestern Venezuela and western Colombia and Ecuador in the south to Minnesota in the north, to Oregon, Idaho, and California in the west, to Florida in the east, with vagrants occurring as far north as southern Canada. Their habitat for foraging is on the ground in clear areas such as pastures,[4] wetlands and mangroves,[14] and chaparral. The grackles' range has expanded with agricultural and urban settings.[12]
Great-tailed grackles are noted for their diverse foraging habits. They extract larvae and insects from grassy areas; eat lizards, nestlings, and eggs; forage in freshly plowed land; remove parasites from cattle, and eat fruits (e.g., bananas, berries) and grains (e.g., maize, corn on the cob by opening the husks).[6] They turn over objects to search for food underneath, including crustaceans, insects, and worms, they hunt tadpoles and fish by wading into shallow water, and although they do not swim, they catch fish by flying close to the water's surface, and are even reported to dive a few inches into the water to retrieve a fish.[6] They are also known to pick dead insects off the license plates of parked cars,[16] and kill barn swallows while flying.[17]
Great-tailed grackles communally roost in trees or the reeds of wetlands at night and, during the breeding season, they nest in territories using three different mating strategies: 1) territorial males defend their territory on which many females place their nests and raise young, 2) residential males live in the larger colony but do not defend a territory or have mates, and 3) transient males stay for a few days before leaving the colony to likely move on to another colony.[18] Resident and transient males sire a small number of offspring through extra-pair copulations with females on territories. Territorial males are heavier and have longer tails than non-territorial males, and both of these characteristics are associated with having more offspring.[18]
Great-tailed grackles can solve The Crow and the Pitcher puzzle - a problem involving a tube that is partially filled with water and a floating, out-of-reach piece of food.[19] The problem is solved by dropping objects into the water to raise the level and bring the food within reach. They are also behaviorally flexible, changing their preferences quickly in response to changes in cognitive tasks.[19]
In Mexico, where it is known as the chanate or zanate, there is a legend that it has seven songs. "In the creation, the Zanate having no voice stole its seven distinct songs from the wise and knowing sea turtle. You can now hear the Zanate's vocals as the Seven Passions (Love, Hate, Fear, Courage, Joy, Sadness, and Anger) of life." Mexican artisans have created icons in clay, sometimes as whistles that portray the sea turtle with the zanate perched on its back.[14]
In Colombia, the species is called the maria mulata,[20] and is the official bird of Cartagena, Colombia.The Cartagena artist Enrique Grau had an affinity for these birds and, because of this inspiration, many Colombian monuments and artistic works were created in honor of the bird's intelligence, adaptability, cheerfulness, sociability, collaborative tendencies, diligence, craftiness, and ability to take advantage of adversity.[21]
In Austin, Texas, it is commonly found congregating near the city's numerous food trucks, and grocery store parking lots.[22] The great-tailed grackle has become an icon in the city, and especially on the campus of the University of Texas at Austin, to the extent that local radio station KUT offers grackle-themed socks as a popular gift for its supporters.[23]
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female, Guatemala The great-tailed grackle or Mexican grackle (Quiscalus mexicanus) is a medium-sized, highly social passerine bird native to North and South America. A member of the family Icteridae, it is one of 10 extant species of grackle and is closely related to the boat-tailed grackle and the extinct slender-billed grackle. In the southern United States, it is sometimes simply referred to as "blackbird" or (erroneously) "crow" due to its glossy black plumage, and similarly it is often called cuervo ("raven") in some parts of Mexico, although it is not a member of the crow genus Corvus, nor even of the family Corvidae.
