By John Keeling
The Great-tailed Grackle is one of the more common birds along the shores of our lake, particularly near the pier in Ajijic and in the trees along the main street in Chapala. They are noisy. The call is a raucous, squeaky whistle which is not exactly pleasant. If you travel between here and Mexico City, you will see these birds everywhere, both in towns and in the countryside.
Great-tailed Grackles are similar looking to the Common Grackle known up north, however they are bigger, and you will notice that the tail is almost as long as the body. The male, shown in the photograph, is jet-black and many of the feathers have a blue or purple iridescent sheen which shows up in sunshine. The female is smaller and has a brown head and neck.
You will find them along lakes and waterways and irrigated pastures. They prefer areas with clumps of mature trees either in towns or near homesteads.
Throughout the last century this species has expanded its normal range northward from Mexico into the US. While it used to be uncommon in Texas, it is now common there and is found in many states up to Kansas and even to the Canadian border. The explosive period of this expansion occurred in the last 50 years, and has been attributed to growth in the use of irrigation for agriculture. It occurs as a non-migratory resident from Kansas all the way down through Central and South America as far as Peru.
In the breeding season the males will display to females and to other males. The male conspicuously spreads its wings and tail feathers, lifts its beak into the air, quivers and fluffs up the body feathers while making a series of squeaking calls. The mature male selects a few trees as its exclusive territory, and will then attract several females to build nests in his territory.
The nests are built half way up taller trees or shrubs, positioned in a fork of the small limbs at the end of a branch, hidden by leaves. The nest is a cup constructed of interwoven grasses and small twigs. Nesting commences in March and repeat nesting may occur into July.
The male with a territory will attempt to keep other males out. However, both sexes are far from faithful in their mating habits. The male will protect the nests in its territory against other species which might want to eat the eggs or the young. The female will defend the area around its nest.
They are omnivorous, which means they will eat almost anything – lizards, small snakes, snails, crayfish, plants, grains, nuts and fruits, as well as the eggs and the hatchlings of other birds.
When you see great-tailed grackles, watch how proudly they strut!
(Ed. Note: John Keeling and his wife lead ‘Los Audubonistas del Lago’ which is a loose-knit group of people interested in birds. To receive notices of events please leave your e-mail address at www.avesajijic.com.)
For more information about Lake Chapala visit: www.chapala.com