Saturday, November 03, 2007

-- Of Mangos and Dead Horses --

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For those who don't already know, Green-breasted Mangos are large flashy hummingbirds of Central America, occasionally documented in the US. One was recently confirmed in Georgia, an interesting find to be sure. Most that have ventured into the US
over the years though, have been found in Texas (16 or more), not a far cry out of their range, and thusly not so difficult to account for. But in the past, one such bird was documented in western North Carolina and, 7 years later, another in Wisconsin. The probability of a Mango, by its own volition, making it as far north as WI., or even NC. (when they've not been seen anywhere north of Texas) I believe is vanishingly small, and so have always presumed these two individuals likely got trapped in the back of carrier trucks (possibly hauling tropical plants, as there are many trucks moving south to north doing such) and released when the sliding back door opened upon destination arrival. 'Little brown jobs' (sparrows and wrens) get trapped in the back of large trucks with some regularity and there's no particular reason it couldn't have happened twice (or more) to Mangos in 7 years --- in fact, I think it far more probabilistic than any other explanation. Thus, I find it interesting that David Sibley actually believes it more likely these two birds are true vagrants, which I would term "wishful thinking" ;-) pretty much unsupported by any evidence (such as intervening sightings between Texas and farther north). But of course neither of us can know for sure...

But it got me to thinking... what would it take to convince me there really were vagrant Mangos traveling so far north? --- It would take 'numbers;' i.e. not 1 or 2 isolated cases, but a half-dozen of them, in a more condensed time-frame, showing up in northerly locales --- that might begin to be persuasive that something really is going on here other than the randomness of the long haul freight industry.
AND AGAIN, (you knew I was headed somewhere with this ;-) THAT is what we have with Ivory-billed Woodpeckers --- numbers --- 1 or 3 or 5 or even a dozen sightings over the many years might easily be written off as mistakes, but not so likely for the dozens of claims piled up over that elapsed time (NOT all of which are brief, or undetailed, or from non-credible sources, or coming in the middle of IBWO frenzy, despite what some will say).

I'm beating a dead horse here with those who disagree, but I'll repeat it nonetheless: UNTIL there are adequately thorough searches of a majority of pertinent habitat areas, and while sightings continue to infrequently occur, there is NO SOLID EVIDENCE for the extinction of this species (just solid evidence of rarity). Invoking the fact that birders make mistakes
as a blanket explanation for so many varied claims across time, is almost insultingly simplistic; a catchall explanation that can be used for anything. And again, if skeptics truly believe that 'brief' identifications are so regularly UNreliable, than I challenge them to come out foursquare against the inclusion of brief sightings on any-and-all official bird counts --- such reports should have no place in databases if their unreliability is as commonplace as painted (funny thing, that brief sightings are accepted so routinely on count days; brief looks of Pileateds are apparently never subject to error, and brief looks of IBWO are 100% subject to error).

If several more years of significant searching result in no documentation for Ivory-bills I'll have no problem saying it looks as though the species may be extinct afterall (though I'll still have no idea in which decade the extinction occurred). And some of us can then say with a clear conscience that we gave it our all, and erred on the side of the bird. But if in that time the species is confirmed what will skeptics have to say...? "geee, sorry, my baaaad," or will some of them be sooo busy packing their bags for a swing by the swamp to get a look just so they can check it off their (unvalidated) lifelists, to bother saying anything at all --- and I'll just bet, by that point, in their estimation, a 2-second look will have magically become plenty sufficient time for putting it on that lifelist, and recounting their wonderful story 100 times over when they return home....

P.S.... in all of this, I don't mean to sound overly harsh with David S.; he's easily one of the most civil and well-spoken folks in these whole proceedings... but this doesn't mean, as I'm sure he'd admit, that he might not be 'mistaken' about both the Green-breasted Mango and the Ivory-billed Woodpecker.
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