Blackbird Overpopulation:
The Problem and One Proposal's Failure

In 2001, the U.S. Department of Agriculture's Animal and Plant Health Inspection Service (APHIS) proposed a three-year plan to kill 6 million Red-winged Blackbirds in North and South Dakota by setting out poisoned rice to kill them during spring migration. The U.S. Fish and Wildlife Service refused to grant the permits required to kill these birds during spring, when the red-wings are not causing damage. However, during late summer and fall when red-wings are causing damage to crops, farmers are allowed to kill them. This lesson will provide you with background to understand what the problem is and one proposed solution, and will show you how governmental agencies made their decision about it. Students will learn how scientists and governing agencies collect data, determine how serious a problem is, and make decisions about possible solutions.

Background Visualization

Photo Courtesy of Ann Cook

Imagine that you are a beautiful three-year-old male red-winged blackbird. You arrived on your marsh on March 1, while ice still covered most of the pond. You set up a territory and defended it against all the other males, attracted three females and helped each of them to raise four babies. A crow flew in and stole three babies from one nest, and one baby died from a parasite, but you've successfully fledged eight babies. Two of the females nested again, and again you helped them raise their babies. Raccoons killed all the babies in one of these nests, and a crow killed two in the other, but two other babies survived. Whew! You've been busy!

Now it's the end of July and you're ready for a well-deserved rest. You join a huge flock of blackbirds and set off for a new feeding habitat--fields where you can find seeds to replenish your stores of fat after the hard breeding season and before winter.

Now imagine you're a farmer. This spring and summer you spent hundreds of hours planting a crop and tending to it, and watched it ripen over the summer. The money you will earn from the crop will go to pay your mortgage payment on your house, buy food and clothes for you and your family, and pay for many of your other needs. But just before you're ready to harvest it, in fly thousands of blackbirds. You desperately try to scare them off, but they keep coming back until they've eaten most of your crop. How would you feel?

Blackbird Population Explosion
From 1996 to 1999, the red-winged blackbird population in the Dakotas rose 33%! That's an enormous increase. During spring and the breeding season, even so many redwings don't cause problems for humans because they eat mostly insects. But once the baby blackbirds have fledged, families join huge flocks and switch their diets to grain and seeds. During the day they feed in fields, and they spend the night in thick stands of cattails, in "roosts" that can number over a million birds. Because they do most of their feeding near the roost, farm fields farther than 5 miles from roosts are usually fairly safe from blackbird damage.

How Big Is the Problem?
Every year, sunflower growers throughout the U.S. suffer losses to their crops. On average, they lose

  • 6% to disease
  • 7% to insects
  • 5% to weeds
  • 3% to waste when harvesting with combines

Over most of the nation, loss to blackbirds is negligible, but in North and South Dakota, they lose about 1 - 2% of the crop every year. This sounds negligible, too, but a few farmers lose an enormous portion of their sunflowers. Every year about 500 growers lose more than 25% of their crops to blackbirds. But interestingly, a recent APHIS study estimates that Red-winged Blackbird populations have increased by 33% from 1996 to 1999 while damage to sunflower crops has stayed about the same.

Different Solutions
Here are some of the solutions some people have tried or considered:
  • Fall Poisoning. For years farmers growing sunflower seed have set out poisoned rice in their fields when sunflowers are ripe. This is permitted by the US Migratory Bird Treaty Act, which protects birds but in some cases does allow people to kill them when the bird is in the act of destroying property. The problem is that ripe sunflowers are the blackbirds' favorite food, and so they hardly ever take the poisoned grain.
  • Scaring the Blackbirds. Farmers have tried a lot of different scare tactics--setting out decoy snakes and owls, helium balloons, and noisemakers like propane cannons. One farmer flew over his fields in a helicopter while playing Willie Nelson songs at top volume.
  • Changing the Habitat. Reducing the amount of cattails nearby significantly reduces the number of blackbirds roosting in that area. Cattails can be bulldozed out, or farmers can use a herbicide called glyphosphate that isn't too toxic to other things and is the safest herbicide for wetlands.
  • Insurance. All sunflower growers could contribute to a policy that paid for the losses that a few growers suffer from blackbird damage.
  • Compensation from Birdwatchers. People who purchase sunflower seeds for feeding birds could pay a small extra fee called a surcharge that could be used to reimburse the farmers who lose large amounts of their crops to birds.
  • Spring Poisoning. This is the proposal many farmers wanted APHIS to adopt. The plan was to kill 2 million Red-winged Blackbirds every spring for three years, during the time they migrate through Dakota fields. Rice containing a bird poison would be set out, with some healthy blackbirds in traps whose calls would attract migrants down near the poisoned rice. Birds that ate the rice would die in one to three days from destruction of their kidneys.

How the Government Made the Decision
Two U.S. government agencies had important roles in this issue. The U.S. Fish and Wildlife Service is charged with protecting native American birds and other resources, to ensure that they will last for future generations. The U.S. Department of Agriculture (USDA) is charged with helping farmers to succeed, in order to ensure healthy food supplies for all American. Farmers are allowed to kill blackbirds that are causing damage, if they catch them in the act. The USDA is allowed to poison birds that are causing problems, too. But without permits from the U.S. Fish and Wildlife Service, the USDA is NOT allowed to poison birds that are not causing immediate damage. This red-wing proposal was to bait and kill migrating birds that were not causing damage.

In its findings, the US Fish and Wildlife Service decided against the permits because

  • there is no evidence that the proposal would actually kill the same birds causing the problems, so there is no evidence the proposal will actually help the farmers.
  • other species could have been poisoned along with red-wings, including rare grassland species such as Baird's, Grasshopper, and Lark sparrow.

Meanwhile, farmers who are losing their crops are strongly petitioning the U.S. Department of Agriculture and APHIS to do something about the blackbird problem, and many of the farmers feel that the only solution is to kill as many blackbirds as possible. The U.S.F&WS continues to conduct studies and may give their approval to some poisoning projects if studies indicate that the blackbirds likely to be killed in these projects are from the same population that feeds in the sunflower fields in fall, that other species are not likely to be killed, and that the project has at least some likelihood of solving the problem.

Try This! Role Playing Game
You might want to start with Journey North's lesson : Exposing All Sides: Guide to Making Informed Opinions.

For this role-playing game, some students as individuals or teams should take the following roles, and research and brainstorm about what their needs and wishes are, and how they could go about getting their way. Then the players must present their viewpoints, and the rest of the class will listen to the different points of view and make a decision about what they'd do to solve the problem. These are the roles. You may add more if you like.

  • Sunflower farmer who lost most of last year's crop to blackbirds
  • Sunflower farmer who has never lost his crop to blackbirds
  • Landowner with a small wetland who discovers hundreds of decaying dead blackbirds that had been poisoned elsewhere and flew to his marsh to die
  • Birdwatcher
  • U.S. Fish and Wildlife Service agent
  • APHIS agent
  • Person living on the same road as the sunflower farmer
  • Someone who lives in a city and buys sunflower seeds for feeding birds
  • Member of the American Bird Conservancy
  • Member of the Humane Society
  • Person who works for the company that makes pesticides
  • Biologist who studies red-winged blackbirds
  • Member of the National Audubon Society
  • Member of the National Sunflower Association
  • Newspaper reporter

To help students research their roles, they might want to check out:

Discussion and Journaling Questions:
  • What are your feelings about this issue?
  • How important is the redwing poisoning issue compared with other issues?
  • Which people involved with the issue do you think have the strongest emotions about it?
  • Which people involved with it have the most solid information?
  • If you were in charge of the world, how would you solve the problem?