Problem Solving
Grackles and Blackbirds Taking Over
These are native, federally protected birds, so every legitimate answer is exclusion. Fortunately exclusion works well, because grackles are big, heavy and awkward on small feeders.
The short answer
- Common grackles, red-winged blackbirds and brown-headed cowbirds are native birds protected by the US Migratory Bird Treaty Act. Killing, trapping or removing them is illegal. Exclusion is the only lawful approach.
- Perches under about 3/4 inch (2 cm) and no seed tray make a tube feeder awkward for a bird the size of a grackle and comfortable for chickadees and finches.
- A caged feeder with a roughly 1.5 inch (4 cm) grid excludes grackles and starlings completely while small songbirds pass through.
- Grackles reject safflower. Cardinals, house finches, chickadees and titmice eat it, which makes it the cheapest single change you can make.
- Most invasions are seasonal flocks passing through in spring or fall. Shutting the feeders down for one to two weeks breaks the habit and costs the resident birds nothing.
Common grackles (Quiscalus quiscula), red-winged blackbirds (Agelaius phoeniceus) and brown-headed cowbirds (Molothrus ater) are native North American birds, and they are protected by the Migratory Bird Treaty Act. Killing them, trapping them, relocating them or destroying active nests is illegal. That is not a technicality about a bird nobody likes; it is the law and it is the frame for this entire page.
The workable answer is exclusion, and the good news is that exclusion is unusually effective here. A grackle is a big bird with big feet and it needs somewhere to stand. Take away the standing room, take away the foods it prefers, and it leaves without any argument.
This page covers how to tell these birds apart from starlings, the exact perch and grid dimensions that separate a grackle from a chickadee, where safflower fits, the one to two week shutdown that breaks a flock's habit, and why most invasions end on their own.
Which bird are you actually looking at?#
The distinction matters because European starlings are introduced and outside the MBTA, while everything below is native and protected.
| Bird | Size | Field marks | Status |
|---|---|---|---|
| Common grackle | 12.5 in (32 cm) | Long keel-shaped tail, pale yellow eye, bronze or purple gloss | Native, protected |
| Boat-tailed and great-tailed grackle | 15 to 18 in (38 to 46 cm) | Much longer tail, coastal and southern | Native, protected |
| Red-winged blackbird | 8.75 in (22 cm) | Male black with red and yellow shoulder, female heavily streaked brown | Native, protected |
| Brown-headed cowbird | 7.5 in (19 cm) | Short conical bill, male glossy black with brown head | Native, protected |
| European starling | 8.5 in (22 cm) | Short square tail, dark eye, white spots in winter, yellow bill in spring | Introduced, not protected |
Female red-winged blackbirds are mistaken for large sparrows constantly, and cowbirds are mistaken for young grackles. If you are unsure, look at the tail and the eye: a long tail and a pale eye means grackle.
Native and protected means exclusion only
There is no lawful backyard route that involves removing these birds. Trapping, shooting, poisoning and destroying nests are all prohibited under federal law, and the narrow depredation provisions that exist are for agricultural and health situations, not feeders. Everything on this page changes the feeder, the food or the schedule instead.
Perch length, trays and feeder geometry#
Grackle exclusion is mostly a matter of denying a large bird a foothold.
Perches under about 3/4 inch (2 cm). A short peg is all a chickadee, goldfinch, titmouse or house finch needs. A grackle cannot balance on it long enough to feed, and neither can a starling. Some tube feeders are sold with long dowel perches or continuous rings, which are the opposite of what you want here; short-perch models exist and cost the same.
No seed tray. A tray bolted under a tube feeder is the most common self-inflicted grackle problem. It converts a feeder they cannot use into a platform they can. Take it off while the flock is around.
No platform feeders. An open platform or tray feeder is a grackle buffet, and there is no way to make one selective. Store it for the season.
Weight-activated feeders. These close the ports when a heavy bird lands. They were designed for squirrels, and a grackle at around 4 ounces (115 g) is light enough that many models do not trip. Treat them as a partial measure.
Domes set low. A weather dome lowered to sit just above a tube feeder physically blocks a bird with a grackle's wingspan from working the upper ports. Cardinals lose out too, so it is a trade.
Cages: the reliable barrier#
A cage with a grid of roughly 1.5 inches (4 cm) is the closest thing to a guarantee. Chickadees, titmice, nuthatches, goldfinches, house finches, downy woodpeckers and juncos pass through it. Grackles, red-winged blackbirds, starlings, jays, doves and squirrels do not.
The cost is real: you also exclude northern cardinals, rose-breasted grosbeaks, jays and mourning doves, which are birds most people are feeding on purpose. The usual compromise is one caged feeder that always works plus one open safflower feeder for the cardinals. Formats, grid sizes and what each one keeps out are compared in caged and selective feeders.
Cowbirds are the exception to be careful about. At 7.5 inches (19 cm) they are the smallest of this group and some individuals will work a 1.5 inch grid, so pair the cage with a seed switch if cowbirds are your main issue.
Leave cowbird eggs alone
Brown-headed cowbirds lay their eggs in the nests of other birds, and people who learn this often want to remove the egg. Doing so without a federal permit is illegal, because the cowbird is a protected native species. Report concerns to your state wildlife agency rather than acting on a nest yourself.
Safflower and the seed swap#
Safflower seed does more work than any other single change. Grackles, starlings and most squirrels reject the bitter coating, while cardinals, house finches, chickadees, titmice and doves eat it without complaint.
At the same time, cut the foods that pull blackbird flocks in:
| Food | Draws grackles and blackbirds | What to do |
|---|---|---|
| Cracked corn | Strongly | Stop entirely during a flock |
| Millet and milo in cheap mixes | Strongly | Read the label and switch mixes |
| Sunflower hearts and chips | Strongly | Pause; offer in-shell instead |
| Peanuts, shelled or loose | Strongly | Only in a mesh or caged feeder |
| Suet in an open cage | Strongly | Move to an upside-down feeder |
| Bread and scraps | Strongly | Never a good feeder food |
| Safflower | Barely | Make it your main seed |
| Nyjer in a finch feeder | Barely | Keep it |
| Whole sunflower in the shell | Moderately | Keep, in a short-perch tube |
Switch to safflower gradually, mixing it into your usual sunflower over about two weeks. Birds are conservative about unfamiliar seed and an abrupt change can empty a feeder of the birds you like as well.
Suet is often the real magnet
Grackles work an open suet cage hard, and they will strip a cake in a day. An upside-down suet feeder shuts them out for the same reason it shuts out starlings: they will not hang inverted to feed, and woodpeckers and nuthatches will. The details are in keeping starlings off feeders.
The one to two week shutdown#
When a flock has settled in, the fastest reset is to stop being a food source.
- Take down every open feeder: platforms, trays, hoppers, open suet cages, peanut dishes.
- Leave up only caged feeders, nyjer, and safflower in a short-perch tube, or take everything down if the flock is large.
- Rake or sweep the ground so no spilled seed remains, since the spill is often what holds them.
- Hold for one to two weeks.
- Restart with safflower, short perches, no trays and inverted suet.
Flocks are mobile and opportunistic. A site that stops producing food drops off their circuit quickly, and they rarely return in force the same season. Your resident chickadees, nuthatches, woodpeckers and cardinals are unaffected by the gap, as covered in do birds become dependent on feeders.
Timing: most invasions are seasonal#
Grackles and red-winged blackbirds are migratory across most of their range, and the heavy feeder pressure comes in waves rather than year-round.
- Late winter to spring, roughly February through April. Northbound flocks arrive and can be dramatic, then thin out as birds pair off and disperse to breed. This is the classic "the grackles have taken over" season across the East and Midwest.
- Late summer to fall. Post-breeding flocks form again and roam widely before and during migration.
- Winter. In the Southeast and parts of Texas, large mixed blackbird flocks are a winter fixture rather than a passing event.
If your invasion starts in March, the honest advice is that patience plus safflower will probably outlast it. Seasonal context for the spring surge is in spring bird feeding.
What does not work#
Scare devices. Owl decoys, reflective tape, spinners and balloons work for a few days at most. Flocking birds habituate fast.
Ultrasonic repellents. No reliable evidence of an effect on birds in yards.
Feeding them somewhere else. A corn pile at the far end of the property makes your address more attractive to blackbirds, not less.
Anything lethal or removal-based. Illegal for these species, and pointless anyway, since a mobile flock is replaced from a regional population within days.
A setup that holds through a flock#
- Safflower as the main seed in a tube feeder with perches under 3/4 inch (2 cm) and no tray.
- One caged feeder with a 1.5 inch (4 cm) grid for chickadees, finches and titmice.
- Suet only in an upside-down feeder.
- Nyjer in a small-port finch feeder, which blackbirds ignore.
- No platform, no ground feeding, no cracked corn while the flock is present.
- Ground spill swept weekly, using the tactics in seed mess, hulls and dead grass.
Grackles are worth a moment's appreciation while you exclude them. They are native birds doing what native birds do, and in most yards the takeover ends within a few weeks whether you act or not. Acting simply makes those weeks cheaper.
Frequently asked questions#
Is it legal to get rid of grackles?
No. Common grackles, red-winged blackbirds and brown-headed cowbirds are native North American birds protected under the Migratory Bird Treaty Act, so killing them, trapping them, or destroying active nests and eggs is a federal offense with narrow permitted exceptions that do not cover backyard feeders. The lawful and effective approach is exclusion: change the feeders, change the seed, or stop feeding for a couple of weeks.
What perch length keeps grackles off a feeder?
Aim for perches under about 3/4 inch (2 cm). A chickadee, finch or titmouse grips a short peg easily, while a grackle at roughly 12.5 inches (32 cm) long has nowhere to balance and gives up quickly. Pair short perches with no seed tray, because a tray turns any tube into a platform the bird can stand on.
Do grackles eat safflower seed?
Grackles generally reject safflower, and so do starlings and most squirrels, while cardinals, house finches, chickadees and titmice eat it readily. It is not absolute and a very hungry flock may sample it, but switching a feeder to safflower removes grackles from that feeder in most yards. Change over gradually across about two weeks.
Why did dozens of blackbirds suddenly show up?
Grackles, red-winged blackbirds and cowbirds gather into large mixed flocks outside the breeding season and move between food sources as a group, so most invasions are migration or winter flocking rather than a permanent change in your yard. They typically stay days to a few weeks. Removing the open food shortens the visit.
Will taking my feeders down for two weeks lose the birds I want?
No. Chickadees, titmice, nuthatches and woodpeckers use many food sources across a wide area and treat a feeder as one stop among many, so a two week gap does not harm them and they return within a few days of refilling. A flock of grackles, by contrast, moves on and generally does not come back to a site that stopped paying.
How do I keep cowbirds away without hurting them?
Stop offering cracked corn, millet, milo and hulled sunflower on the ground or on a platform, since ground and tray feeding is what draws cowbirds. Switch to safflower and to tube feeders with short perches. Brown-headed cowbirds are native and protected, so removing them or interfering with their eggs is illegal.