European starlings are wildly successful by any measure. Discounting a failed attempt to introduce them in Portland in the late 1800s, the first individual was observed in Oregon in 1943. Populations quickly exploded, and just 20 years later they were abundant throughout.
Starlings are despised by many, and I wonder why. OK, they can be an agricultural pest, especially around fruit, but so can robins. Maybe beautiful singers get a pass. Yes, starlings can overwhelm a feeder and chase away more timid species. Still, this seems insufficient to explain the level of disdain many have for this bird. Could it be we dislike success itself? Consider crabgrass, dandelions, and in many places in the Rogue Valley, deer. Humans hate the competition.
So what makes starlings so successful? First, they are assertive. Some might say aggressive. When they find a nest cavity they want, be it in a tree or nest box, they take it. This often leaves others, such as ash-throated flycatchers, swallows and western bluebirds, without a home.
I have seen other birds stand up to starlings on only two occasions. The first involved a pair of starlings building a nest in a hollow in an oak. One morning the agitated birds repeatedly approached the hollow and scolded loudly, dropping the now-forgotten nesting material they had been carrying, but after several hours they abandoned the nest. That evening two yellow eyes at the entrance told the tale. There is no intimidating a screech owl.
The second incident involved a northern flicker. I watched the flicker leave a cavity high in a cottonwood with an egg in its mouth. With a flick of its head the egg fell 50 feet to a rather messy end. The shell was bluish with light brown spotting, definitely a starling egg.
Assertiveness isn’t the only reason starlings have been so successful. They have another trick.
Given the bounty at the local supermarket, most Americans fail to appreciate that food energy limits many if not most animal populations. A bird that uses its limited food resources more efficiently wins. The profit can be converted into more young.
A great many birds undergo two molts a year, including buntings, tanagers, warblers and even some sparrows. They have a summer molt and a late winter molt. The summer molt typically involves the complete replacement of all feathers. This is costly but necessary. Feathers wear out. Usually plumage produced at this time is drab, helping birds avoid predators.
In the breeding season one must take risks to win a mate. The late winter molt produces bright breeding plumage. However, the need for new feathers comes at a terrible time. Food is scarce, and most species molt as few feathers as possible, typically limiting the fresh party colors to the head and breast.
Now, back to starlings. They “cheat.” They have no late winter molt to lose their white-speckled winter plumage. Instead they rely on wear to remove the white spots on the ends of their feathers, revealing the bright, iridescent courtship plumage beneath. The energy savings is great and can result in earlier breeding, more nests and more starlings. They aren’t the only bird to employ this strategy. American robins and western meadowlarks are two more.
While I may not like all starling behaviors, there is much to be admired about this successful bird.
Stewart Janes is a biology professor at Southern Oregon University. He can be reached at firstname.lastname@example.org.