Georgetown Rufous-collared Sparrow: Further Thoughts

First off: What a great find! Congratulations to Tim Davis and Andrew Davis for finding and correctly identifying the bird, and kudos to Joe Roller for getting the word out so quickly.

Hugh Kingery made an excellent point:

> I've always thought it too bad that an exotic is considered
> guilty until proved innocent (if "proof" is the right word).

Sheesh--you'd think the guy is a lawyer or something... ;)

Seriously, Hugh gets at something quite important. It's essential to start off with a reasonable assumption, and then to attempt to test that assumption. (Or even to "prove" it, as in the legal system.) In the U.S. legal systemm, we start off with an assumption of innocence, and then we go about attempting to test that assumption.

In science, the procedure is analogous. We start off with a "null hypothesis," which we attempt to prove--to *dis*prove, actually. The alternative to this "null hypothesis" is called--wait for it!--an "alternative hypothesis."

Let's say I'm on the grounds of the Denver Zoo, minding my business and eating my potato crisps, when, all of a sudden, a splendid Common Grackle and an equally splendid Indian Peafowl saunter up to me and beg for handouts. Naturally, my first instinct is to ask this question: "Can I enter these two species on my Denver County eBird checklist?"

For the grackle, a reasonable null hypothesis, I would say, is that the bird is, for want of a better term, "wild." That's our base line, our starting point, our working assumption. To disprove that hypothesis, we would need information ("data") to contradict the bird's wild status. For example, we might see that the bird is wearing a band that says "Property of the Denver Zoo." But, absent such information ("data"), we stick with our assumption (our "null hypothesis") that the bird is wild.

For the peafowl, conversely, a reasonable null hypothesis, I would say, is that the bird is not wild. Now, suppose someone points out to us that the bird is carrying a small radio transmitter. Upon further investigation, we learn that the transmitter was affixed to the bird in the wild in India, and that the bird flew nonstop across the Indian Ocean, the Middle East, Europe, the Atlantic Ocean, and eastern North America (with continuous signal transmission the whole way), and then landed in the Denver Zoo. In this scenario, we would toss out our assumption (we would "reject the null hypothesis") of non-wild origin in favor of the "alternative hypothesis" of wild origin.

The key point is, You have to start with a well-chosen assumption ("null hypothesis"). The folks who invented our legal system believed that innocence was a good starting point. In the case of our Denver Zoo birds, it depends on the bird: I think most people would agree on "wild" for the grackle, but "not wild" for the peafowl.

So what about the Georgetown Rufous-collared Sparrow? I think it's more likely that the bird is an escape than a vagrant from Mexico or points south. But I don't think the odds are overwhelmingly against natural vagrancy, as in the case of a peafowl at the Denver Zoo. So I'm gonna go with "innocent until proven guilty" on this one. Now, we already have "circumstantial evidence" for its "guilt": I'm thinking of Dennis Garrison's link to Rufous-collared Sparrows for sale in the USA, and Nick Komar's follow-up about I-70 as a good point of escape for the species. But I think further investigation is warranted. I think it might be possible to disprove natural vagrancy for this individual not by circumstantial evidence but rather with an ornithological "smoking gun"--an eyewitness report that the bird jumped out of a Ryder Truck at Jenny's Market, or a band that reads "Hecho en Mexico," or something like that.

All that said, I wonder if we're missing the broader point. This bird IS remarkable. If it flew up here on its own from Mexico (or points south), that's impressive. (And, just to repeat myself, I do NOT think that's the case.) But it's also remarkable if the bird is an escape and surviving on its own in lowly Georgetown. Here's an interesting mini-commentary from Michael Retter's "Sightings" column, p. 20, in the current (May 2011) issue of Birding magazine:

"A Common Crane was in Buffalo, NE 3/24; this species is more frequently detected in NE than in any other state or province in North America. An 'uncountable' Hooded Crane was, if anything, even more impressive; the bird escaped from a facility in ID and got all the way to NE."

Just because a bird is an escape does NOT mean it is somehow unimpressive. Hooded Cranes in Nebraska, Rufous-collared Sparrows in Colorado...good stuff!

By the way, the most impressive avian story of the past decade in Colorado has been the astonishing conquest of our state by the Eurasian Collared-Dove--a population of captive origin, of course.

Let's show this Georgetown sparrow some respect. If it's a vagrant, that's pretty darned impressive. If it's "just" an escape, it's nonetheless a beautiful bird, with a gorgeous song, that must be remarkable indeed to behold in Georgetown; and it's impressive that the bird is, for now, holding its own up there.

And check this out: There always has to that first pioneer. Nick gets at that point, although a bit facetiously. But, seriously, at some point, a Eurasian Tree-Sparrow got it all started in St. Louis; a Eurasian Collared-Dove got it all started in Florida (and, before that, in the West Indies); a Peach-faced Lovebird (coming soon to a checklist near you!) got it all started in Phoenix; and--who knows?--maybe, as Nick has said, a Rufous-collared Sparrow will have gotten it all started in Georgetown. Again, let's show this bird some respect.

Even though it's probably "just" an escape.

A final thought. Christian Nunes said in a recent post to COBirds: "Humans have their fingers in everything, if you haven't noticed." I agree, but with a twist. Yes, we have our fingers in everything--and that ought to affect our perception of birds that we have traditionally thought of as "wild" or "natural." Think of a "wild" vagrant hummingbird at a feeder in New York City in January: Everything about that scenario is overwhelmingly *un*natural. NYC, for starters! And the plastic feeder. And the "hummer juice." And human-caused alterations to the landscape and the climate--affecting not only the individual hummer, but indeed the behavior and ecology of the entire species.

By extension, the next time you see a "wild" vagrant at Prewitt Reservoir, consider just how profoundly *un*natural that occurrence is. A Long-tailed Jaeger flying around an artificial reservoir in Colorado is profoundly human-influenced, in the same manner as a Rufous-collared Sparrow that escaped from an RV in Georgetown.

For further thoughts on the matter, check this out:

http://aba.org/nab/v64n4p548.pdf

If nothing else, you will encounter the longest word ever to have appeared in the title of an ABA publication!

-------------------------------

Ted Floyd
Editor, Birding

Blog: http://tinyurl.com/4n6qswt

Twitter: http://tinyurl.com/2ejzlzv

Facebook: http://tinyurl.com/2wkvwxs

-------------------------------