Flocks of European starlings, so many they look like leaves on trees, are passing through Powell on their yearly southern migration.

Their chatter, sounding like a combination of bird and bug, fills the air. But if you get close enough you can detect another sound: constant splats of their poo hitting branches, cars and the earth from above.

In recent weeks, the starlings have dirtied many local properties, particularly in the northern part of the city.

“It’s been going on for about a month now,” said Ken Hoffmann, who lives just outside the city limits on 14th Street/Lane 8.

“Every evening I try to go out at dusk and discourage them from landing here. They’re messy,” he said. “My desire is to figure out a way to keep them from returning.”

Hoffmann heads out in his yard, shotgun in hand, and sends some bird shot in their direction. “I hit one or two or three. They’re stealing food from the other birds I feed,” he said.

But, like clockwork, a few minutes go by and they come right back. Hoffmann has begun to call them his “pets.”

According to the Cornell Lab of Ornithology, the invasive species is now among the continent’s most numerous songbirds. They’re resented for their abundance and aggressiveness as they move in mobs to residential areas in large, noisy flocks.

“All European Starlings in North America descended from 100 birds set loose in New York’s Central Park in the early 1890s,” the Lab reports. “The birds were intentionally released by a group who wanted America to have all the birds that Shakespeare ever mentioned. It took several tries, but eventually the population took off. Today, more than 200 million European Starlings range from Alaska to Mexico.”

Unfortunately, they are drawn to lawns and farm fields, gorging on just about anything, from bugs, seeds and grains to garbage. They compete for nest space in crevices with native bird species and are known to aggressively chase off waterfowl, flickers, flycatchers, swallows, bluebirds and others.

Starlings can be found in abundance in every state in the country, but are most apparent as they gather in massive flocks during migration. They do so during the winter in part as a defense against predators, said Zach Hutchinson of Casper, community naturalist for the National Audubon Society, Rockies region.

“When they’re in big flocks, they can be a nuisance to some. It’s a technique used by a lot of birds to lower the risk of being nabbed,” Hutchinson said. “The confusion and chaos they present is good for them against predators, but bad for humans when they’re in your trees, pooping on your property.”

In Powell, residents have been seen banging items together and honking horns to scare the birds off their roosts.

European starlings are classified as a “predacious bird” in Wyoming. In other words, you can legally shoot them.

Starlings are one of only two birds classified as predacious in the state, with the English sparrow being the other. While the species can be shot on sight, they often feed with protected birds — and discharging firearms within the city limits is also against the law.

The species do have some benefits, mostly in the number of insects they consume.

“I used to have a deep seated dislike for starlings, but in banding them [for studies] I’ve come to appreciate them more,” Hutchinson said. “They’re quite spectacular when you see them up close.”

Grasshoppers are among starlings’ favorite bugs. While there haven’t been any studies on how many insects they devour, Hutchinson has heard from farmers who appreciate their help with hopper populations. “Insects make up a large percentage of their diet,” he said.

In winter, the birds eat seeds and grains. In Wyoming, they can often be seen feeding on Russian olives — offering perhaps another reason to control the tree species.

“You have one invasive species feeding on another,” Hutchinson said.

One suggestion for minimizing the number of starlings flocking to your property is leaving lawns and fields unkempt. “They don’t like to feed in tall grasses,” Hutchinson said.

Of course, that doesn’t help in town. The City of Powell has an ordinance requiring homeowners to keep their lawns and weeds mowed, said Mayor John Wetzel.

North America, particularly the U.S., is one of the strongholds for starlings. The U.S. has about one-third of the world’s starling population and in places like the United Kingdom, starlings have been disappearing over the past 50 years. “It’s very possible that in the coming years we could have the major population in the world,” Hutchinson said.

For more on starlings, visit Hutchinson’s blog: www.flockingaround.com/post/start-loving-european-starlings