Common Grackle Dossier

by Carl Strang

In anticipation of spring, this week’s choice of species dossier features a bird that winters not so far to our south, and so is one of the first to arrive in spring.

Grackle, Common

Courting group of grackles in a quiet moment.

Typically this is a colonial nester in tall trees, although I have seen low nests (e.g., at Purdue gravel pit). Birds radiate out from the colony to feed, traveling at least up to ½ mile. They feed mostly on the ground, in tall (at least 6″) grass in summer in Pennsylvania, in forests in early to mid-spring in Illinois. Latter birds feed in groups, noisily throwing leaves aside with beaks as they walked. Former ones fed more commonly as individuals.

Squeaky, rusty-hinge voice. In early May 1986, at West DuPage Woods Forest Preserve, Illinois: A large male grackle, perched on a bare branch beside the river, periodically gave his squeaky “erlik-geck” call. Each call was accompanied by elevation of the feathers of the head, neck and upper back and chest. Feather elevation began slightly before vocalization. Alarm call is a series of rapid “geck” notes.

Migrates south for winter, forming large flocks mixed with other blackbirds (especially red-winged) in fall, disappearing in November from northern Illinois and Indiana, reappearing in March. The male holds his long, wedge-shaped tail vertically in long straight flight. That tail also can be held in a V-shape.

Migrant grackle flock, foraging on Mayslake mansion lawn.

Both parents participate in feeding. Nestling grackles at Willowbrook’s hospital were unusual in their lack of aggressiveness in taking food. They would not bite food off its holder (implying regurgitation by parents into the nestling’s throat?). The inside of the mouth is dark red on older youngsters.

7MR87. First arrival of year noted at McKee Marsh, Blackwell Forest Preserve.

7MY87. Grackle caught moth it flushed from lawn, removed wings before eating.

4JE87. Broods out of nest, not strong fliers, still begging hard.

11JE87. Mother grackle fed youngster several items, apparently brought up from her crop although some she picked up nearby on the ground. After she flew off, the fledgling pecked at the ground, picking up dropped bits, and also did some close looking of its own into the grass.

14SE87. Migrants in Willowbrook Back 40, also one on 28th.

6MR88. Numbers of grackles are back.

2AP88. Grackles flying in pairs and showing much courtship activity in past week.

8AP89. Grackles mostly in pairs.

17JE89. A broad-winged hawk calling repeatedly, in north end of Maple Grove. Jays, flickers and grackles highly agitated, flickers the most continuously vocal with “keels” every 2 seconds (2 birds). Grackles gacking frequently, too.

18JE89. Grackles foraging in forest litter, Maple Grove and Meacham Grove Forest Preserves.

Grackles perched near a nesting colony.

30JE96. As I paddled my sea kayak on Lake Michigan, just north of the IL-WI border, I saw many grackles along that 2-mile stretch foraging over the surface of the water. Both genders. The birds flew pretty much straight out from shore, 100-200 yards, and then flew back and forth until they saw something on the water to pick up. Then the bird dropped down and reached for the item with its bill. There were lots of dead and dying small fish, and on at least 2 occasions these clearly were what the grackles picked up. At other times the objects appeared to be too small or the wrong shape. Sometimes a grackle dropped down and appeared to miss, or not even quite reach the surface, but it seemed that after a single try, successful or not, the bird headed straight back to shore (sometimes dropping down to the water on the return trip, though). They flew along as high as 30 feet, usually 10-15, and when seeing objects they spun on a wing and often hovered, looking surprisingly tern-like. They minimized contact with the water, though one that dropped down close to me, where I could see clearly, plunged its head into the water, and its tail tip dipped in as well. Their fluttering flight appeared clumsy and energy-gobbling when compared to the purple martins, gulls and terns also cruising those waters.

22FE99. First of year noted at Willowbrook.

12AU99. 2 grackles hunting up in trees.

2NO99. Last of season at Willowbrook.

31OC01. Flocks of red-wings and grackles remain (Nelson Marsh, Kane Co.)

4NO01. An enormous flock of red-wings and grackles along Kirk Road in eastern Kane County. The species were staying apart, on the whole, and there were mainly grackles, but there were hundreds of each. They were landing in a harvested corn field.

18MR09. Both red-wing and grackle include tail fanning and wing spreading in their displays. In the red-wing, these movements accompany the song but are expressed in a range from not at all or nearly so, to slight fanning of tail, slight tail fanning and spreading of wings, and finally much tail fanning and wing spreading.

Grackle courtship flock, displaying

1JE09. Mayslake. First grackle fledglings.

18MR11. Mayslake. Most grackles still are males, but a female often is among them from the start (when a pair forms do they leave, so males always outnumber females?).

29MR11. Mayslake. Displaying grackle group. Often there is only one female with the several males. In the past week or two I frequently have noted trios of flying grackles, one female with 2 males.

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