A couple weeks ago, I linked a story from Richmond, Virginia, in which a large flock of cedar waxwings became stuck in pigeon repellent. Many of them died on the scene; others died at a rehabilitation center. Recently, two more waxwings died, bringing the total deaths to about 60. (It is difficult to find an exact body count.) The remaining survivors are still in rehabilitation.
According to the Virginia state government, the repellent was "an EPA registered product ... used in accordance with the manufacturer's instructions." That does not mean that its use was wise or even legal. The repellent is not named in the news stories, but it is usually described as "a sticky substance." Sticky repellents have been known to cause problems in the past. (See the cases from Arizona and New York.) The Humane Society recommends that such repellents not be used for pigeon control:
Sticky substances (polybutenes) are sold to discourage pigeons and other birds from landing on treated surfaces and are often marketed as "humane." However, The HSUS does not recommend these products because they can adhere to and foul the feathers of pigeons who comes into contact with them, and are even more harmful to smaller species and various "non-target" birds.The Cornell Lab of Ornithology also warns against use of sticky repellents (in this case against woodpeckers):
Although some people recommend applying sticky repellents such as Tanglefoot Pest Control, Roost-No-More, and Bird Stop to areas where damage is occurring, we are against using them. These products can get on a bird’s plumage, impairing its ability to fly and stay warm.The incident may also be a violation of the Migratory Bird Treaty Act. Rock pigeons, of course, are not protected by the law because they are a nonnative species introduced by humans. However, cedar waxwings are protected; killing several dozen of them is an unauthorized take.
Presumably the state workers involved in the decision-making or application of the repellent did not intend to harm other wild birds. I have some sympathy for their desire to discourage pigeons from roosting around the Capitol. Pigeons are messy creatures, and many visitors and workers probably find their repulsive.
However, wildlife control measures should not be implemented willy-nilly and should affect only animals that are causing a problem. Building managers should not take the word of "control experts" that their methods are humane. Likewise, EPA registration is not a guarantee that a chemical is safe. (See, for example, the case of carbofuran, which was "an EPA registered product" until its registration was canceled in 2006.) The products to be used should be researched thoroughly prior to implementation. At the very least, this should involve some internet searches (beyond the first page of results). In the case of a state government, ideally the research should involve consultation on potential risks with the state's own wildlife agencies. Wild birds face many threats to their survival; careless use of pigeon control should not be one of them.