Great Tailed Grackles are in the Piney Woods
By Jay V. Huner
Grackles are blackbirds. Most blackbirds associated with the piney woods are black or some shade of dark brown with the exceptions of the orange and yellow orioles. You've seen one black bird. You've seen them all! But, the male Great-tailed Grackle is, in breeding plumage, a magnificent sight, shimmering in iridescent black and purple with tails as long as their bodies. You just have to watch blackbirds carefully to appreciate that there are several very different, unique species.
I've mentioned Great-tailed Grackles in a past report about Common Grackles. Common Grackles are The Great-tailed Grackles' "little brothers" and found all over open areas of the piney woods in the South. In our region, the Red River-Atchafalaya River drainage is the current eastern limit of the Great-tailed Grackle's range .
Originally a species of Central America extending northward through Mexico into southern Texas, these grackles extended their range at the beginning of the 1900s northward into the plains states, westward California, and eastward to the Mississippi River. Come back in 50 years and they may well have moved into the eastern states and, perhaps reached the Atlantic Ocean.
Much has been recorded about the negative impact of man on bird habitat and populations. In the case of the Great-tailed Grackle, man's impact on the natural world through urbanization and irrigated agriculture has allowed this species to expand its range and numbers! In fact, Great-tailed Grackle roosts in urban areas can reach thousands with resultant noise and bird waste problems!
The tails of breeding male Great-tailed Grackles are as long as their bodies and are keel-shaped. Following breeding, the long tail feathers are replaced and sometimes all are lost at once so that the birds look like a large flying blob of black feathers.
Female Great-tailed Grackles are rich brown and about half the male's size. Both males and females have bright yellow eyes. Both sexes also have long sloping heads and huge bills. These features help to separate Great-tailed Grackles from Boat-tailed Grackles which in our region have dark eyes and rounded heads. In addition, they are normally found in coastal areas where Great-tailed Grackles are rare.
Male Great-tailed Grackles exhibit elaborate displays to attract mates and discourage competing males from choice breeding habitat. They also have very interesting vocalizations. An ear-splitting whistle is often heard. Sometimes a repetitive clacking sound similar to a child's machinegun can be most annoying. Then, too, there are all sorts of moaning and croaking sounds to draw attention to roosting and nesting sites!
If it moves and is small enough to eat whole or tear apart, the omnivorous Great-tailed Grackles will eat it. This includes, like the other grackle species, small fish, crustaceans including crawfish, birds, mammals, frogs, lizards, snakes and all manner of insects and related invertebrates. Then, too, they eat all manner of vegetables, fruits and nuts. Huge flocks can cause all sorts of mischief to agricultural crops.
Great-tailed Grackles do engage in communal nesting where a "social" male will have several mates that he guards in a nesting area. However, genetic testing show that this male is not the father of all the young birds that his various wives produce!
Because male Great-tailed Grackles are so large and have more metabolic needs than the females, mortality of males is higher than females. As a result, the sex ratio is skewed toward females.