Grackles can be a major nuisance for both agricultural and structural bird control especially when they congregate into huge flocks to roost in trees at night. They have been very difficult to control in the past, but Flock Free has developed some highly effective techniques to deal with them. The most difficult scenario is when they inhabit restaurants, pool areas and places where people eat food as they, like gulls, become very familiar and even aggressive when there is food present.
Grackles are sensitive to the methyl anthranilate emitted from our hazers or applied in Tank Mix.
Hazers placed under trees where the product will rise to meet the birds-in-flight have proven very successful. Power may be a limiting factor as many trees are in areas where there is no power. Contact Flock Free Bird Control for more information. Flock Free Tank Mix should also be used in trees or bushes, landscape areas and other places where birds are active.
Grackles Outside – Structures, Pool Areas, Restaurants
The birds will normally land or perch somewhere they can watch for food. Identify these areas and develop a plan to irritate them where they are landing if possible. Umbrella protectors are great for the tops of umbrellas and Shock Tape can be used on the edges of roofs to prevent them from landing.
Grackles in Trees
Grackles can become overwhelming problems in trees. You are best to use a combination of the products and techniques listed below for best results
Shock Sticks –are 4-foot-long artificial perches that, when birds land on them, convey a static shock. Place in trees where grackles are roosting
Spray trees regularly with Flock Frees Tank Mix Liquid Bird Control Repellent.
The common grackle
(Quiscalus quiscula) is a large icterid which is found in large numbers through much of North America.
Adult common grackles measure from 28 to 34 cm (11 to 13 in) in length, span 36–46 cm (14–18 in) across the wings and weigh 74–142 g (2.6–5.0 oz). Common grackles are less sexually dimorphic than larger grackle species but the differences between the sexes can still be noticeable. The male, which averages 122 g (4.3 oz), is larger than the female, at an average of 94 g (3.3 oz). Adults have a long, dark bill, pale yellowish eyes, and a long tail; its feathers appear black with purple, green or blue iridescence on the head, and primarily bronze sheen in the body plumage. The adult female, beyond being smaller, is usually less iridescent; her tail, in particular, is shorter, and unlike the males, does not keel (display a longitudinal ridge) in flight and is brown with no purple or blue gloss. The juvenile is brown with dark brown eyes.
Distribution and habitat
The breeding habitat is open and semi-open areas across North America east of the Rocky Mountains. The nest is a well-concealed cup in dense trees (particularly pine) or shrubs, usually near water; sometimes, the common grackle will nest in cavities or in man-made structures. It often nests in colonies, some being quite large. Birdhouses are also a suitable nesting site. There are four to seven eggs. This bird is a permanent resident in much of its range. Northern birds migrate in flocks to the southeastern United States.
Ecology and behavior
The common grackle forages on the ground, in shallow water or in shrubs; it will steal food from other birds. It is omnivorous, eating insects, minnows, frogs, eggs, berries, seeds, grain, and even small birds and mice. Grackles at outdoor eating areas often wait eagerly until someone drops some food. They will rush forward and try to grab it, often snatching food out of the beak of another bird. Grackles prefer to eat from the ground at bird feeders, making scattered seed an excellent choice of food for them. In shopping centers, grackles can be regularly seen foraging for bugs, especially after a lawn trimming.
Along with some other species of grackles, the common grackle is known to practice "anting", rubbing insects on its feathers possibly to apply liquids such as formic acid secreted by the insects.
This bird's song is particularly harsh, especially when these birds, in a flock, are calling. Songs vary from, year round chewink chewink to a more complex breeding season ooo whew,whew,whew,whew,whew call that gets faster and faster and ends with a loud crew hew whew! It also occasionally sounds like a power line buzzing. The grackle can also mimic the sounds of other birds or even humans, though not as precisely as the mockingbird, which is known to share its habitat in the Southeastern United States.
In the breeding season, males tip their heads back and fluff up feathers to display and keep other males away. This same behavior is used as a defensive posture to attempt to intimidate predators. Male common grackles are less aggressive toward one another and more cooperative and social than the larger boat-tailed grackle species.
Grackles tend to congregate in large groups, popularly referred to as a plague or annoyance. This enables them to detect birds invading their territory, and predators, which are mobbed en masse to deter the intruders.
Relationship with humans
The range of this bird expanded west as forests were cleared. In some areas, it is now considered a pest by farmers because of their large numbers and fondness for grain. Despite a currently robust population, a recent study by the National Audubon Society of data from the Christmas Bird Count indicated that populations had declined by 61% to a population of 73 million from historic highs of over 190 million birds.
Unlike many birds, the grackle benefits from the expansion of human populations due to its resourceful and opportunistic nature. Common grackles are considered a serious threat to crops by some, and notoriously difficult to exterminate and usually require the use of hawks or similar large birds of prey