Answer: Who Caused the Demise of Bluebirds in North America?

Answer: Who Caused the Demise of Bluebirds in North America?


What's going on with bluebirds, Henry IV, and their possible population demise?

When I heard the original comment on the radio, I was able to track it down by finding the program web site (in this case, "To the Best of Our Knowledge" at and find the program (search for [ Shakespeare starling ] and you find it in one click), and then listen to the program again.

In the radio show (and in the book "How Shakespeare Changed Everything") Stephen Marche writes that starlings were mentioned in one line of Henry IV, part 2, which then motivated Bronx pharmacist Eugene Schieffelin to introduce 60 pairs of starlings into Central Park in the winter of 1890. That succeeded so well that there are now, 120 years later (2012), more than 200 million starlings in North America, where they cause huge damage to fruit crops, buildings and... incidentally… other birds.

That's such an astonishing claim that I had to see if it was true.

The easy way to find this thread of a topic is to search for:

[ bluebirds extinction ]

Which leads to a number of articles (including the Wikipedia article on bluebirds, noting that there are 3 different kinds of bluebirds in the U.S.) that all mention competition between starlings and bluebirds, and all point to Eugene Schieffelin as the perpetrator. (My favorite article in the Bluebird genre is: "A history of Bluebirds" by the Sialis organization, so named for the Latin name for the Eastern Bluebird. It's marvelous what fans will do.)

A little background research on Eugene Schieffelin reveals a real character. He was a member of the American Acclimatization Society as the group that released starlings into Central Park as a kind of art project in 1890 to make Central Park a little more cultured, and that meant Shakespearean.

Lest we judge them too harshly, this really was before people understood the terrible effects that introduced speicies could have in a new ecosystem.

As it turned out, most of the birds they introduced from Shakespeare's mentions turned out to be harmless or low reproducers. The exceptions-starlings and English sparrows-continue to plague North America to this day.

Short answers to questions:

1. WHAT connection does Henry IV have with the collapse of bluebird populations?
The starling was mentioned in "Henry IV, Part 1" for its remarkable mimicry abilities, where it was to be used as a constant reminder of a wrong my repeating the name of the wrongdoer. They were introduced to New York in 1890 and propogated wildly across North America. But it turns out that starlings bully several native species, often evicting bluebirds and woodpeckers.

2. WHO was such a fan of Henry IV that he caused the demise of bluebirds in North America?
Eugene Schieffelin, a pharmacist in the Bronx, New York City.

Finally, WHAT is the name of the organization that sponsored his (now notorious) act that led to the problems with bluebirds?
Schieffelin belonged to the American Acclimatization Society

Wait... there's more!

Several people pointed out that in a Scientific American article from May 2008, Steve Mirsky writes that starlings actually appear to be innocent in the case of the missing bluebirds. The feather friends at the Cornell Laboratory of Ornithology contend on their Web site that

"…a study in 2003 found few actual effects on populations of 27 native species. Only sapsuckers showed declines because of starlings, and other species appeared to be holding their own against the invaders." So when it comes to songbird decline, as Shakespeare almost said, maybe the fault is not in our starlings but in ourselves."

That's a clever closing line. I saw this SciAm article as well, so I did a bit more looking. First, I found the original paper: Koenig, W. D. 2003. European starlings and their effect on native cavity-nesting birds. Conservation Biology 17: 1134-1140. pdf

This is where the quote comes from…

Then I did a search like this:

[ starlings bluebirds ]

And discovered that in a more recent article (2012), the Ornithology Lab at Cornell NOW says:

"…They often out-compete woodpeckers, Great Crested Flycatchers, Tree Swallows, Eastern Bluebirds, and Purple Martins for nesting sites. Consequently, the populations of these and other native cavity-nesting species have declined."

In another web article, Cornell's Ornithologists write: "They [starlings] nest in cavities (holes in trees, buildings, and nest boxes) and will aggressively destroy eggs and kill nestlings of native birds (like bluebirds and woodpeckers) to use their cavities."

This made me curious, so I started looking at Google Scholar for a few papers in the recent ornithological literature to follow up on this.

[ bluebirds starlings ] — on Google Scholar, which I then sorted by date to see the latest hits

This leads to a paper: "The relationship between introduced European Starlings and the reproductive activities of Mountain Bluebirds andTree Swallows in British Columbia" Canada (Koch, et al.; International Journal of Avian Science, v 154, n 3, p 590-600, July 2012)

The gist of which is:

"Starlings and Mountain Bluebirds showed inverse trends in nest abundance. Mountain Bluebird clutch sizes were smaller if they were initiated later in the breeding season…"

Which boils down to this: Where starlings go, bluebirds have a tough time. They compete for nesting cavities and food resources. And, tellingly, starlings will actively and aggressively evict bluebird nestlings.

So it's not quite an open-and-shut case, but the preponderance of evidence does seem to be that starlings stress bluebirds (and sapsuckers).

And for all the hassle that starlings cause, you still have to appreciate the writing style of this article about starlings vs. bluebirds from Sports Illustrated (Robert Cantwell, 1974):

"There are about 110 species of starlings in the world, but the only one in North America is the European starling, Sturnus vulgaris, which until Schieffelin went to work ranged from Great Britain to parts of Mongolia. The starling averages 8" in length and has a lustrous metallic sheen to its greenish-black, lightly spotted plumage. It has a yellowish-white bill and short legs set wide apart, which give it a bowlegged appearance. Starlings walk rather than hop, placing one foot in front of the other in a way that makes them appear pigeon-toed. They have a peculiar swinging gait, as though they were shouldering someone off a sidewalk. They travel in flocks, and when they feed along the ground they walk fast, all heading in the same direction, staying close together, and moving with a purposeful, disciplined and deliberate air; no grazing or straying, just eating and hurrying along in search of mischief."

That's great, muscular writing. While it would be rejected by any decent scientific journal, you can't help but feel an appreciation for the starlings, bullies though they may be.

Search lessons: As we've talked about before, you often need to dig one or two layers deeper, especially when you run across information to the contrary of what you're expecting. Be sure not to fall prey to confirmation bias, just keep checking until you see the latest interpretation of events.

Keep searching!

Wednesday search challenge (8/15/12): Who caused the demise of the bluebirds in North America? | SearchReSearch


Image via Ralph and Jenny.