[MASSBIRD] ABA Checklist Update–fairly long / potentially boring

[Neil Hayward]

Dear Massbirders,

(If you're not interested in taxonomy or US listing please feel free to ignore, or do something more interesting like finish making that cranberry sauce!)

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The American Birding Association (ABA) published the 2017 update (v8.0) to its checklist yesterday. This is one of the more significant changes we've seen. The ABA voted last year to include Hawaii in its territory, and this checklist now includes countable Hawaiian species, together with their new codes. (ABA codes run from 1 to 6 for abundance, where 1 is common and 6 is extirpated or extinct). 105 new birds were added from Hawaii (many introduced), although almost a third are code 6, reflecting the mass extinction that has befallen many of the endemics there, especially the honeycreepers.

The incorporation of Hawaii means that some of the codes have become more common, as rarities in the traditional ABA area (henceforth known as "ABA Continental") are not so rare in Hawaii. Hence, White-tailed Tropicbird (currently a Code 3 rarity) becomes a Code 2 (uncommon regular). Similar changes happen with Red-footed Booby and Wedge-tailed Shearwater, among others.

Some of the code changes reflect changes in abundance in the existing ABA Continental area, or changes that more accurately reflect the abundance. Hence, some examples:

• Iceland Gull–Code 2 (previously Code 1)
• Brown Booby–Code 2 (previously Code 3). So, this is no longer a "rarity", which presumably means it won't trigger eBird rarity alerts. 
• California Condor–Code 2 (previously Code 6). This reflects the current countability of Condor which had been listed as extirpated (code 6).
• Tufted Flycatcher–Code 4 (previously Code 5). This species has started to breed in AZ, is now annual, and so doesn't qualify for the extreme rarity status that is code 5.
• Nutting's Flycatcher–Code 4 (previously Code 5). Same reason as for Tufted Flycatcher.
• Himalayan Snowcock–goes from Code 2 to Code 3 rarity. This is a bit of a head-scratcher. This exotic is resident in the Ruby Mountains of Nevada and they don't go anywhere. To my mind, it's no different than Colima Warbler, a very locally restricted birds in small numbers but a regular breeder.
• Common Ringed Plover moves from Code 2 to Code 3 rarity. Long overdue! As a Code 2 (due to its very restricted breeding range in western AK, primarily St. Lawrence Island), this never triggered eBird rarity alerts, much to the annoyance of almost everyone who'd like to see one in the Lower 48, or anywhere else outside of Gambell!
• Bristle-thighed Curlew also moves from Code 2 to Code 3, probably for the same reason as the plover above. But BTCU does winter in good numbers in HI (where it's relatively easy to find and photograph), so it's perhaps a stretch to consider this as a Code 3 rarity.
• Yellow-footed Gull similarly moves to become a Code 3. 
• Brown Jay becomes rarer (Code 3 to Code 4) reflecting the lack of recent records. As much of the required habitat connecting Mexico to the Rio Grande Valley has been lost, so to have Brown Jays. The last Brown Jay in the US was seen in 2012.
• Tamaulipas Crow also moves from Code 3 to Code 4, although ironically, after not being seen for seven years, they finally returned to the beautiful Brownsville Dump earlier this month!
• McKay's Bunting becomes a rarity (Code 3) from Code 2. This is breeding bird on two Bering Sea Island (Hall and St. Matthew) and winters on the west coast of AK (notably at Nome). The Code 3 presumably reflects how inaccessible and difficult to find this species can be.

The new checklist is based on the AOS Checklist (58th Supplement to the 7th Edition which came out this summer). The biggest change for us, at least, was the change in status of Thayer's Gull to a subspecies of Iceland Gull. Thus, Thayer's is no longer countable as a separate species from Iceland.

Four new birds were added to the ABA Checklist from vagrancy (Pine Flycatcher, Cuban Vireo, Amethyst-throated Hummingbird and Common Shelduck). The only one relevant to this region is Common Shelduck. Common Shelduck has turned up with greater frequency at the right times of the year in the right places for it to finally be considered a genuine vagrant, rather than an escape, thus mirroring a similar history in the status of Pink-footed and Barnacle Goose. A number of local birders here chased the three Common Shelducks in New Brunswick last December, and more recently a young bird at Rye, NH. Interestingly, a Common Shelduck was reported here in MA in Nahant / Lynn on December 6/7 in 2009. Establishing the provenance of this bird was problematic, and an escape couldn't be ruled out, but the timing (winter), location (northeast) and age (juvenile) were good pointers for a genuine vagrant. In the 15th Annual Report of the Massachusetts Avian Records Committee, the authors noted that they'd "be willing to revisit the record in the future if evidence of natural vagrancy to the Northeast coast emerges. The record failed on its third ballot, 6–2." Thus, the recent promotion of this bird on the ABA checklist may prompt another discussion about this species here. (2009 was not the only MA record; another bird was reported in Dennis on Jan 24, 2004.)

As a reminder of a recent ABA change, extirpated exotics that no longer appear on the checklist are still countable if you saw them during the time that they were on the checklist. Thus, if you saw Budgerigar during or before 2015 in the Tampa area, you can still count it on your list. Same goes with Crested Myna (Vancouver before 2004) and a few others. A fuller explanation of extirpated exotics can be found here: http://listing.aba.org/aba-checklist-appendix-part-1-extirpated-exotics/

Here's hoping this didn't ruin your culinary preparation for tomorrow.

Happy Thanksgiving!

–Neil

Neil Hayward

Cambridge, MA

[alice morgan]

We had a Common Shelduck on East Beach in Dartmouth on Oct. 3, 2003. At least two other birders saw it. We assumed it was an escapee. 

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Alice & Dane Morgan
Brookline & S. Dartmouth, MA