Three species of grackles occur in North America - the common, boat-tailed, and great-tailed. The common grackle (Quiscalus quiscula) is the most widespread and mobile of the species, occurring the farthest north and west. It can be found throughout the United States (east of the Rocky Mountains) and Canada (Nova Scotia to Alberta). So let's get into it, do grackles migrate?
Many common grackles do migrate, which is why they are the most mobile. They typically spend the summer breeding season in the north, then migrate south for winter. These birds are considered short-distance migrants, however. They do not travel far, and some do not migrate at all.
The grackles that live in the central United States and farther south are permanent residents in their territories. Any ideas as to why that might be? Read on to discover more about the migratory habits of the grackle!
The majority of Common Grackles do, in fact, migrate
Grackles typically begin spring migration back to northern breeding grounds in February and March - a fairly early start for most bird species. On the other hand, southern migrations take place in late fall, usually peaking around October or November.
These migration patterns are consistent with the common grackles that live in the northern regions of the species range. In warmer climates, grackles tend to be year-round residents.
When grackles migrate, it is usually to avoid overwintering in colder climates where food sources are scarce.
As you likely know, the Canadian Territories and northernmost regions of their range in the United States can have long, harsh winters. Grackles largely rely on seeds for winter food supply, but even these can be hard to come by when everything is covered in several inches or feet of snow.
To avoid a long winter and the risk of starvation, these birds will migrate south. However, they usually do not need to travel long distances.
Grackle perched on a wooden fence during the summer
How far grackles migrate depends on how far north their summer breeding grounds extend. Regardless, though, the migratory flights are exceptionally short compared to those of other species.
The grackles summering in Canadian territories may migrate around 600 miles to reach warmer climates in the central or southeastern United States. On the other hand, grackles in the lower regions of the Northeast and Midwest may only travel about 200 miles south.
Grackles do migrate in flocks. They are extremely social birds and often spend the majority of their time in groups (outside of breeding season).
These birds will roost and forage in large flocks often made up of more than one species. The European starling, red-winged blackbird, and brown-headed cowbird are often in the mix. In winter, these groups can number many thousands of birds.
A small flock of Grackles during migration
Not all grackles migrate. Climates in the southern and central United States are mild enough that grackles will stay year-round, using these regions for both breeding and wintering.
Even the grackles of Canada and the Northern United States that do fly south for winter are considered short-distance migrants. They never travel very far from their breeding territories.
In winter, grackles largely spend the day foraging in communal flocks. The birds will visit crop fields, feedlots, and suburban areas, picking up seeds or livestock feed. They may also rummage through your trash. Bird feeders offer easy meals in the colder months as well.
The flocks are typically composed of several different species of blackbirds. These birds roost together at night and generally stay in the same groups until breeding season approaches.
Grackle perched on a branch
Grackles are well adapted to survive winter. The bird's main defense is to migrate south away from the colder, northern regions of their range. However, this does not mean they escape winter weather altogether.
Throughout the cold season, grackles spend their days foraging for seeds to keep their energy levels up, which in turn helps them stay warmer. When natural food resources are scarce, these birds are likely to visit backyard feeders. If your yard isn’t covered in a thick blanket of snow, they may even search along the ground for insects or fallen seeds.
Traveling and roosting in large flocks also helps grackles survive the winter. There is safety in numbers. Roosts are often in large trees, offering some protection from the elements.
A group of Grackles at a bird feeder in the backyard, during the winter
Grackles that migrated south for winter will leave in summer to fly back to their breeding grounds. Many grackles, though, are year-round residents in the central and southeastern United States.
Some grackles do move south for the winter. Those that spend the summer breeding season in the northern and northwestern regions of their range typically migrate south to the warmer climates of the central and southeastern United States. The grackles already living in these warmer climates do not migrate.
Close up portrait of a Common Grackle (Quiscalus quiscula) on the ground
Common grackles do occasionally migrate to Texas. Eastern Texas also has a permanent population of this species. On the other hand, the great-tailed grackle (another subspecies of this bird) is a year-round native resident of the southern half of Texas.
Common grackles, the only subspecies of grackles found in the Great Lakes region, will migrate from northern Michigan to the southern border or just outside of the state. This is why grackles are known as short-distance migrants. They often do not need to travel very far between breeding and wintering grounds.
Three species of grackles occur in North America - common, boat-tailed, and great-tailed. The common grackle is the most widespread and mobile of the species, occurring throughout much of the United States - east of the Rockies - and Canada. The boat-tailed grackle occurs exclusively along the southern Atlantic Coast and Gulf Coast of the United States. The great-tailed grackle resides in the southwest and Mexico.
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