Hello, All:

A common rule of thumb I've heard numerous times in Ohio is that as the
size of a flock of Trumpeter Swans grows, the probability that NONE of the
birds will have neck bands rapidly approaches zero.  I've never heard
anyone suggest that this a definitive distinction (and it certainly is
useless with singletons or very small groups), but wondered if one of the
better informed Ohio Listers might be able to address whether this is still
a useful data point when flocks of native swans are observed.

Bird well,

Paul

On Mon, Feb 20, 2012 at 3:19 PM, Victor Fazio <[log in to unmask]>wrote:

>  Reading Bill Whan's succinct message on Ohio swans, I have
> to say he is right on the money. I would like to go a bit further
> and say that after 5 years of reviewing several thousand swan
> entries in eBird, that among the most problematic ID issues in
> Ohio is that involving swans.
>
> This is no more evident than at Ottawa N.W.R., Magee Marsh W.A.,
> and Metzger Marsh in late April and May. Ebird review permits me
> to call up all records of both species simultaneously allowing a
> side-by-side comparison. In a way, EBird is self-policing in that
> at popular birding sites I can see a degree of corroboration or
> lack thereof in the multitude of other checklists. This only applies
> to the last 5-6 years where there is sufficient sample size.
>
> When I examined every Tundra Swan report for these marshes
> from late April through May, none were accompanied by a
> Trumpeter Swan record. While not impossible, it is improbable
> when compared with the dozens of other checklists in the
> same time frame only reporting Trumpeter Swans.
>
> In the most dramatic case, in May 2007 a host of about 25-30
> swans were present at Metzger Marsh. One party reported
> nothing but Mute Swans, another party nothing but Trumpeter
> Swans, and another party nothing but Tundra Swans (on
> the same day).
>
> FYI: In the absence of corroborating details, I am forced to
> invalidate conflicting entries such as these.
>
> Part of the problem was at my end in that the May checklist
> filter erroneously allowed for Tundra Swan sightings without a
> call-out from EBird. I changed that a couple of years ago and
> there have been no May records since.
>
> While detecting such aberrations at the edge of the distribution
> of a species is fairly straightforward, doing so well within their
> respective distributions is much more challenging. And this winter
> has been especially
> so. The introduction of eBird 3.0 in October greatly streamlined
> the data entry process making it much more user friendly. In
> doing so, now one need not examine one's list at all for errors.
> One is encouraged to do so, but only after the fact of submitting
> the record. In recent months, I have now contacted about a dozen
> persons regarding conspicuous (read flagged) swan entries that
> proved to be erroneous typos. But how many have I missed?
>
> I can only ask that if anything is flagged in eBird, that you
>
> PLEASE, PLEASE, PLEASE
>
> check the data entry. And if you have an issue with the item being
> flagged by all means comment to that effect. At a minimum, I will know
> you intended that data entry. And if I agree with your position, I will
> change the threshold, or otherwise provide an explanation for it.
>
> Looking at a snap shot of Trumpeter Swans in Ohio for mid-January 2012
> among those that are corroborated and for which I accept as valid, the
> state wide tally accounts for about 80-85 birds. The highest valid single
> concentration from past years (54) is from a Ottawa N.W.R. census Nov 2008.
> the next two highest counts of 50 and 47 are also O.N.W.R. counts
> with the latter from 1 January 2012.
>
> I will happily stand corrected should higher verifiable tallies be made
> available.
>
> There are several much higher counts without any corroboration from inland
> Ohio that seem highly improbable and, without details, I am left no choice
> but to leave invalidated.
>
> Finally, a clarification regarding Trumpeter Swan movements. It is
> generally
> true they disperse little and not far however there are some exceptions.
> Namely, there are several Pennsylvania and Virginia
> records, of which some are birds from Ohio. One of the Virginia records
> is published in North American Birds. The other is very recent. See ...
>
> http://www.flickr.com/photos/22374475@N07/6847490621/in/pool-437129@N20/
>
> or this eBird entry
>
> http://ebird.org/ebird/view/checklist?subID=S9778289
>
> Birds of the Upper Midwest (Minnesota/Iowa) do seem to be developing
> greater dispersal capabilities and routinely reach Oklahoma and may well
> be responsible for recent Texas sightings. Do any of these birds augment
> winter populations in Ohio? I have no idea.
>
> This plot of winter distributions of the Trumpeter Swan for the past 10
> years
> may be informative.
>
>
> http://ebird.org/ebird/map/truswa?neg=true&env.minX=-104.62501571425179&env.minY=28.6734397372551&env.maxX=-62.43751571425179&env.maxY=43.820425522158736&zh=true&gp=true&mr=12-2&bmo=12&emo=2&yr=2002-2012&byr=2002&eyr=2012
>
>
> OR
>
> http://preview.tinyurl.com/6mpvajb
>
>
> Keep in mind that "Swan sp." or "Trumpeter/Tundra Swan" are perfectly
> legitimate data entries in eBird.
>
> .
> NOTE:
> .......ANY correspondence should address me at [log in to unmask]
>
> and I welcome any inquiries regarding eBird.
>
> cheers
>
> Vic Fazio
> Shaker Hts, OH
>
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--

Paul H. Dubuc,

Validation Consultant
(609) 356-9517 cell
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(800) 458-2634 fax

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