Friday, November 03, 2006

"a little knowledge is a dangerous thing"

Reports of rare or unusual birds can sometimes lead to mass hysteria, and an observer’s expectations of seeing a rare or unusual bird can lead to self-delusion, resulting in common birds being mistakenly identified and reported as something else entirely (usually the rare bird that the observer was expecting to see). I know this to be true, as it has happened to me (more on that later, maybe).

Tom Nelson recently brought to light one such case in which a woodpecker sighted in Florida by an amateur birder and initially reported as an Ivory-billed Woodpecker later turned out to have actually been a common Red-bellied Woodpecker.

This phenomenon is not new. An early example was brought to light by Jonathan Dwight in the April 1918 issue of The Auk. Dwight was one of the founding members of the American Ornithologists’ Union. Clearly, the problem of evaluating sight records is something that ornithologists have had to wrestle with since amateurs and professionals started keeping track of birds and their movements. And it has been the vexation of State bird record committees since their inception. A surprisingly large proportion of the rarities submitted to bird record committees lack these "Minimum considerations for verification of sight records." Which leads one to ask, "How many of Cornell's seven reported Arkansas sightings of Ivory-billed Woodpeckers would have been accepted if submitted to a bird record committee for review?"

6 Comments:

Blogger Bill Pulliam said...

The recent case you and Nelson cite is from an observer who by their own description knows absolutely nothing about birds. This person is no more an "amateur birder" than I am an "amateur cricket player." It was also posted to an open public form directly by the naive observer; it was not brought forward by anyone with any ornithological knowledge as any sort of evidence for IBWO survival. It is of no relevence whatsoever to understanding the issues of sightings by experienced, skilled observers, such as is the case with a very few of the recent reports. I'm surprised and a bit disappointed that you decided this was worthy of spotlighting, considering the plethora of irrelevence and distraction already swamping the IBWO discussions.

November 03, 2006 2:19 PM  
Anonymous Anonymous said...

When innocent people are put in jail, isn't usually because of faulty eye-witness identification?

If we can't even readily identify our own species after a brief glimpse, why could we expect to do so with other species?

November 03, 2006 7:43 PM  
Blogger John L. Trapp said...

The recent case you and Nelson cite is from an observer who by their own description knows absolsutely nothing about birds.

Okay, Bill, in my excitement and haste, I admittedly overstated the familiarity of the observer with birds. At first glance, his blog gives the impression that he is an enviornmentalist, or at least a greenie, but that certainly does not connote a knowledge of birds, as is made abundantly clear in the last sentence of the last-referenced blog entry, where he says, "before these sightings, I didn't know there were woodpeckers in FL."

By the way, this observation was reported by the observer on his personal blog; to his credit, he later realized his mistake and published a correction in a separate blog entry. The existence of the blog entries (the initial report and the correction) were brought to the attention of the BirdForm community by a third party, from which they were linked by Tom Nelson.

Given that he knew little or nothing about woodpeckers, what is it that led this naive observer to the conclusion that he had seen an IBWO? That, I think, has fascinating social and psychological implications. Many of the IBWO sightings that have come to light over the years are by novices who have no more knowledge of woodpecker ID than the gentleman from Florida.

As evidenced by the Jonathan Dwight article, the phenomenon of naive observers misidentifying common birds as somthing rare or unusual and reporting them as such to authorities, is nothing new. In my opinion, even experienced observers can sometimes delude themselves into thinking they have seen something they haven't.

November 05, 2006 10:49 PM  
Anonymous Anonymous said...

"In my opinion, even experienced observers can sometimes delude themselves into thinking they have seen something they haven't."

I think this is the key point. Forget some dude who "didn't know FL had woodpeckers". Consider instead Auburn.

Clearly, Auburn went out in the field shortly after the CLO announcement and "found" Ivory Bills. A clear case of observer expectancy bias if there ever was one.

Just because a person is educated, even a PHD, doesn't mean they aren't prone to bias. Dr. Hill et al will now be ridiculed for many years. And the Florida knot-head will escape any long term effect.

Why? Because we expect more from our PHDs.

November 06, 2006 11:51 AM  
Blogger Bill Pulliam said...

The fact that people with little or no knowledge of natural history often report Ivorybills, Carolina Parakeets, Condors, Thunderbirds, and Bigfoot is nothing new. In the 1970's Atlanta Audubon had a designated person to handle all the "I have one of those Ivory Bill Wood Peckers at my bird feeder" phone calls. This shows that people who know nothing about nature can imagine that they have seen just about anything, and are highly influenced by popular media and mythology. But of what real relevence is this to the evaluation of reports from people who in fact do know quite a lot about nature and how to observe it? The phrase "weapon of mass distraction" comes to mind.

I dare say that distinguishing individuals of the same species is rather a different task than distinguishing individuals that are not even in the same genus. A better comparison would be to ask how often you mistake your mother for a gibbon, rather than how often you mistake her for the milkman. Certainly it happens, but not very frequently. And I daresay you have probably not ever called 911 to report that an escaped orangutan was enjoying its breakfast at your kitchen table, only to discover that it was in fact your spouse.

I don't expect high field ID skills from Ph.D.s; I expect them from experienced birders who may have a Ph.D. or may have never finished high school. What I expect from Ph.D.s is the ability to discuss matters of science in a sensible fashion. Well, actually, perhaps "hope" is a better word than "expect."

I believe Dr. Observer Expectancy Bias may biased towards seeing Observer Expectancy Bias.

November 06, 2006 10:42 PM  
Anonymous Anonymous said...

Bill, bill, bill,

It's not statistics that lie. It's incompetent sampling of populations that turn out not to be the populations that you thought you were sampling.

That Hill was totally biased to seeing IBWOs where none existed is practically admitted by him. He says he was primed and desirous to "see".

You really need to revisit much of the new statistical work on bias and incompentency in sampling. You may know statistical analysis. But you need more training in sampling.

But that's true of most people. So don't take it too hard. Statistical sampling is difficult. And takes actual field experience to fully understand just how hard it is to do right. And even then, it's often done wrong.

This IBWO fiasco of Observer Expectancy Bias is fodder for many a future college statistics course.

November 08, 2006 11:39 AM  

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