Date: 2/28/17 8:13 am
From: Michael Schrimpf <michael.schrimpf...>
Subject: Re: [nysbirds-l] Red-tailed Hawk subspecies and eBird reporting them
Hi all,

I don't usually post to the list - I'm presently a PhD student at Stony
Brook, and also volunteer as an eBird reviewer.

I certainly agree with Shai that in most cases it is safe to assume that
all individuals observed belong to the common taxa, and when those are
reported in regions where this assumption is safe, eBird reviewers are
expected to accept those records. So, those Yellow-shafted Flickers in
Shai's example would all be validated in a NY checklist, even if an
observer may not have studied all 27 of those flickers carefully - that
would not be the case in western Kansas (where reporting flickers to
subspecies does require careful examination).

Speaking for myself (not with any authority from eBird Central) I
respectfully disagree with Shai's claim that it would be "incorrect" to
report those individuals that were seen clearly to subspecies, while
reporting the others to species.

Any analysis of the distribution of one of these taxa will need to make
filtering decisions about how to treat those individuals not recorded to
subspecies, and in this case would treat any 'Northern Flickers' as
Yellow-shafted Flickers, so the total numbers would not wind up being
misleading at all. I suppose that if you are scanning some of the output on
the eBird website, and looking through numbers of Yellow-shafted Flickers
alone (without the context of the rest of the checklist), it could be
misleading, but I see that more as a limitation to the data exploration
tools. Data recorded in different categories can always be lumped, but not
always split, so in my opinion recording finer scale information (like
which individuals you were able to ID to a more specific taxa) should not
be considered 'incorrect'. That is actually one reason why I make more
liberal use of the "spuh" and "slash" categories in eBird than many other

While these are my views on the topic, I would welcome input from the eBird
team leaders (who have had many similar discussions internally and on the
eBird reviewer listserv). I've cc'ed Marshall Iliff here, and will put the
question to the reviewer listserv as well.

Michael Schrimpf
Suffolk County

On Tue, Feb 28, 2017 at 9:39 AM, Shaibal Mitra <Shaibal.Mitra...>

> Hi Rich and all,
> This is a very interesting piece and definitely a helpful way to begin a
> broader conversation on this topic within the bird records community.
> As explained in this article, the question of how to report species and
> their subspecies is quite complex. I've thought about this a lot and have
> derived a set of guidelines that can be applied to the problem in a more
> general way, including the related challenge of reporting other sets of
> nested taxa, such as spuhs and their constituent species.
> Having read the article on Red-tailed Hawk taxa in Vermont, there are some
> issues that I think deserve extra emphasis.
> At the level of species and their subspecies, in most situations there is
> exactly one identifiable subspecies that is overwhelmingly more frequent
> and abundant than any other subspecies at any given site and any given
> date. There are actually surprisingly few situations in which the second
> most likely subspecies of a given species occurs frequently enough that it
> poses any challenge to the simple equation that a report of the species
> equals a report of the default subspecies in that situation.
> For a large number of species, only one subspecies has ever been recorded
> in a given area. For instance, all Northern Flickers ever studied
> critically in New York State have been Yellow-shafted, without even one
> exception in all of time. It would be flatly incorrect and misleading to
> include on a Vermont eBird checklist something like:
> 23 Northern Flicker--migrating
> 4 Northern Flicker (Yellow-shafted)--studied carefully
> Such an approach would mis-represent the number of Yellow-shafted Flickers
> observed, and the appropriate approach is to report 27 flickers as one line
> item, and it doesn't really matter which category one uses because they are
> effectively identical in Vermont in the 21st Century.
> At the next level of complexity, there are many cases in which one
> subspecies occurs regularly whereas others occur as rare vagrants. Thus, it
> can be presumed that all Brant observed on Long Island are hrota unless
> explicitly suspected as something else. It is simply an error to record
> something like this on a checklist from Jamaica Bay:
> 1 Brant (Black)--photos
> 300 Brant (Atlantic)--studied carefully
> 2,000 Brant--estimated
> Again, this grossly mis-represents the number of Atlantic Brant observed.
> The 2,000 neglected Brant can be assumed to be hrota because the greatest
> conceivable number of vagrant orientalis, bernicla, etc. that could be
> present is a very small number, hovering around zero at all times, and
> clearly smaller than the error implicit in the estimate. Whether one uses
> "Brant" or "Brant (Atlantic)" is almost irrelevant because the two are
> quantitatively equivalent on Long Island, but one should never use both.*
> Examples of genuine numerical uncertainty are really quite few in the
> northeastern United States. Familiar examples include Greater and Lesser
> Snow Goose (though these are quite difficult to identify and should
> probably be left alone under most circumstances for that reason alone), and
> Yellow and Western Palm Warblers. Apparently Red-tailed Hawks in Vermont
> represent another example of this sort of exceptional case, because
> abieticola is suspected to occur, at least potentially, at a high enough
> frequency in some seasons that it would be inaccurate to presume that all
> Red-tailed Hawks are borealis.
> Shai Mitra
> Bay Shore, NY
> *An exception to this guideline arises when a specific individual bird is
> intermediate-looking and has to be listed as generic "Brant" (with copious
> notes and photos) because it looks neither like prevailing hrota nor
> vagrant orientalis--or when a particular swan grebe might be listed as
> "Aechmophorus sp." because it looks different from the regular vagrant
> "Western Grebe" but sounds different from the mega-rarity "Clark's
> Grebe".....:)
> ________________________________________
> From: <bounce-121283286-11143133...> [
> <bounce-121283286-11143133...>] on behalf of Richard Guthrie [
> <richardpguthrie...>]
> Sent: Tuesday, February 28, 2017 7:30 AM
> To: NYSBIRDS_L; <hmbirds...>; <midhudsonbirds...>
> Cc: <iworley...>
> Subject: [nysbirds-l] Red-tailed Hawk subspecies and eBird reporting them
> With Ian's permission, I'm delighted to share his informative article
> about differentiating Red-tailed Hawk subspecies that may also be found in
> New York State. To read the article and see the pictures, please visit the
> Vermont eBird website at:
> recognizing-subspecies-in-vermont/
> And feel free to visit Vermont and report your hawk, and songbird, duck,
> woodpecker, etc. sightings up there as well. : )
> Rich Guthrie
> New Baltimore,
> The Greene County,'
> New York
> ---------- Forwarded message ----------
> From: Ian Worley <iworley...><mailto:<iworley...>>
> Date: Mon, Feb 27, 2017 at 7:06 PM
> Subject: [VTBIRD] Red-tailed Hawk subspecies in Vermont .... and how to
> submit them to eBird
> To: <VTBIRD...><mailto:<VTBIRD...>
> Red-tailed Hawk subspecies are catching birders' eyes in neighboring
> states, and now in Vermont. How are they recognized and how should they be
> reported to eBird and the Vermont Bird Records Committee? What if I'm not
> interested in the subspecies?
> These questions are answered in a new article just published on the
> Vermont eBird website:
> recognizing-subspecies-in-vermont/
> If you have questions regarding eBird entries of subspecies, feel free to
> contact any of the six Vermont eBird county coordinators/reviewers: Sue
> Elliot, Craig Provost, Spencer Hardy, Kyle Jones, Ian Worley, and Kent
> McFarland.
> Good birding to all as spring migration rolls in during the next many
> weeks!
> Ian
> ...............................................
> --
> Richard Guthrie
> --
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