Common Grackle

The short answer

• Common Grackles are native and protected under the Migratory Bird Treaty Act, and continent-wide surveys have tracked a long-term population decline even as they remain abundant locally.
• They will not eat safflower at all. Cardinals, chickadees, titmice, nuthatches and house finches all take it readily, which makes it the cleanest single swap available.
• The other reliable answer is a tube-only station: no tray, no hopper, no ground seed. A 115 g grackle has nowhere to stand on a short-perch tube.
• Most of the pressure is a seasonal pulse. Flocks build from late February through May, then break up to nest, and a second pulse follows in late summer.
• Weight-activated perches set to shut out a grackle also shut out blue jays, mourning doves and evening grosbeaks. Decide which of those you want before you buy one.

The Common Grackle is the most awkward bird on this site to write about honestly. It is a native species, protected by federal law, and continent-wide breeding surveys have tracked a substantial long-term decline in its numbers over recent decades. It is also, in March, entirely capable of emptying a 5 lb hopper in a day and driving every cardinal out of the yard.

Both things are true at once. The management below is exclusion and food choice only, which is what the law allows and what actually works.

Identifying it, and the blackbirds it gets confused with#

A grackle in flat light is a big black bird. In sunlight it is bronze or purple-glossed, with the head often a different color from the body, and it has a hard staring pale yellow eye that shows much further away than you would expect. It is long, with a heavy tapered bill and a tail that is nearly a third of its length. In flight the male folds that tail into a shallow V-shaped keel, which no other common blackbird does.

Two behavioral marks are worth as much as the plumage. Grackles walk with the head up in a stiff, deliberate stride, and they routinely carry food to water and dunk it: dry bread, dog kibble, a hard seed. Watch a bird bath in spring and you will see it. They also have a hard keel on the inside of the upper bill used to saw open acorns, which is why they handle food nothing else at the feeder can deal with.

The spring pulse#

Grackle pressure at a feeder is not constant, and treating it as constant is why people overbuy hardware. It comes in two waves.

The practical consequence: if grackles appear in your yard in the first week of March, you are looking at roughly a ten-week problem, not a permanent one. Making a seasonal change (safflower only, trays away, from 1 March to 15 May) is often smarter than rebuilding the station. See spring bird feeding for how that fits the rest of the season.

Behavior at the feeder#

A grackle flock does not fight for a feeder so much as occupy it. Birds arrive in groups of five to forty, land on every horizontal surface, and feed hard for ten to twenty minutes before moving on as a unit. At 115 g a grackle outweighs a cardinal by more than two to one and a chickadee by ten to one, and smaller birds simply wait it out in the shrubs.

Grackles are also efficient in a way that matters to your seed bill. They are ground and tray specialists that clean up everything the tube feeders spill, so a yard with a heavy spill layer under the feeders is feeding grackles whether or not it means to. Sweep or rake the drop zone weekly during the spring pulse, or use a seed catcher, and you remove a resource that no amount of feeder swapping will address.

What they eat, and the two seeds that break the pattern#

1. Hearts Top
2. Cracked corn Top
3. Mealworms Top
4. Black oil Yes
5. Millet Yes
6. Peanuts (shelled) Yes
7. Suet Yes

Cracked corn, sunflower hearts and mealworms sit at the top. Two entries at the bottom are the whole strategy: grackles take no safflower and no nyjer at all. Compare that against the birds you want at the same station.

Top top-tier favorite Yes eats readily Some takes occasionally Rare rarely No not a feeder food

Read the safflower column. Cardinals rate it top-tier, chickadees, titmice, nuthatches, house finches and mourning doves all take it readily, and the grackle takes none. There is no other single swap in bird feeding with a cleaner result, and it works on squirrels at the same time. The trade-offs are covered in safflower versus sunflower: safflower costs more per pound, jays and goldfinches are lukewarm on it, and your regulars will take two to three weeks to accept it. Do not judge the switch in the first week.

The two setups that work#

Setup A: safflower only. Fill every seed feeder with safflower, stop cracked corn entirely, and keep suet inside a wire cage. Cardinals, finches, chickadees, titmice, nuthatches and doves stay. Grackles get nothing and leave. This is the better option if you want to keep a hopper or a tray for cardinals.

Setup B: tube only. Take away every open surface: no platform tray, no ground feeding, no wide hopper ledge. Run short-perch tube feeders with no catch tray, plus a caged suet feeder. A grackle has nowhere to stand and cannot hover-feed for long. The cost is real and you should know it up front: short perches also exclude cardinals, and ground feeding is how you keep juncos, white-throated sparrows and doves. This setup thins your species list to buy quiet.

What does not work#

• Short-term shutdowns. Taking feeders down for two or three days achieves nothing. A flock re-checks a site for well over a week. If you shut down, plan a fortnight and change the food before you restart.
• Visual scares. Owl decoys, reflective tape, spinners and balloons work for a few days at most on a bird this social and this adaptable.
• Slinky springs, monofilament and greased poles. These are squirrel measures. Grackles fly.
• Bigger mixes with more filler. Cheap mix is heavy on cracked corn and millet, both of which grackles rate highly. It makes the problem worse, not cheaper.
• Anything lethal. Beyond being illegal without a federal permit, it does not work: a yard with food in it refills from the surrounding population within days.

Keeping it in proportion#

Grackles are worth watching once they are not eating your entire seed budget. They forage on foot across lawns and ploughed ground, follow farm machinery, wade in shallows for small fish and crayfish, and gather in enormous mixed roosts with starlings and blackbirds in autumn. The species is declining across much of its range even as it looks abundant in any given March, which is a useful reminder that "common" is a snapshot rather than a guarantee.

Managing them is about protecting a feeding station that other birds can use, not about removing a bird from the landscape. If yours are still winning after both setups above, work through the grackles and blackbirds guide, which covers mixed blackbird flocks and the seed-waste layer in more detail.

Frequently asked questions#

How do I keep grackles away from my feeders?

Two approaches work and they combine well. Switch your seed to safflower, which grackles will not eat and cardinals, house finches, chickadees, titmice and nuthatches take readily. Then remove the surfaces they need: take down platform trays, stop ground feeding, and close or replace a wide-ledged hopper. What is left is a tube with short perches and a suet cage inside a wire cage. Expect two to three weeks for your regular birds to accept safflower, and expect the grackle flock to check back for about ten days.

Are grackles protected?

Yes. The Common Grackle is a native North American species and is protected under the Migratory Bird Treaty Act in the US and equivalent law in Canada. It is illegal to kill them or destroy active nests without a permit, unlike the introduced House Sparrow and European Starling. Management at a feeder has to be exclusion and food choice. That is not only the legal position, it is also the effective one, because a flock that finds nothing usable simply moves on.

Why do grackles suddenly show up in spring?

They are among the earliest migrants back into the northern part of their range, and they travel in flocks before they pair off. From late February through May you get a pulse: large numbers moving through, feeding heavily and using your yard as a stopover. Once birds settle into breeding territories the flocks dissolve and pressure drops sharply. If your grackle problem starts in March and you are still fighting it in June, something in the yard is holding them, usually cracked corn or an open tray.

What is the difference between a grackle and a starling?

Size, tail and eye. A Common Grackle is about 115 g with a long keel-shaped tail it folds into a V in flight, a heavy tapered bill and a bright pale yellow eye. A European Starling is about 82 g with a very short square tail, a thin pointed bill and a dark eye, and it looks almost tailless in flight. Both walk rather than hop. In poor light, check the eye first: the grackle's pale iris is visible at a surprising distance.

Do grackles eat other birds' eggs and nestlings?

Occasionally, yes. Grackles are opportunistic omnivores and take eggs, nestlings, insects, small fish, crayfish and waste grain as well as seed. It is real, but it is a normal part of a native predator community rather than a reason to treat the species as an invader. If nesting birds in your yard are the concern, dense native shrub cover and well-placed nest boxes do far more for them than removing grackles ever would.

Sources and further reading

1. Common Grackle Cornell Lab of Ornithology, All About Birds Identification, diet, flocking behavior and population trend
2. North American Breeding Bird Survey US Geological Survey Long-term population trend data for widespread species
3. Migratory Bird Treaty Act Protected Species US Fish and Wildlife Service Federal protection covering native blackbirds
4. Discouraging Unwanted Feeder Visitors Cornell Lab of Ornithology, Project FeederWatch Foods and feeder designs that exclude large flocking birds