Date: 2/28/17 6:41 am From: Shaibal Mitra <Shaibal.Mitra...> Subject: RE: [nysbirds-l] Red-tailed Hawk subspecies and eBird reporting them
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:
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:
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.
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...>
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:
And feel free to visit Vermont and report your hawk, and songbird, duck, woodpecker, etc. sightings up there as well. : )
The Greene County,'
---------- 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
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?
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!