American Birding Podcast



2017 AOS Supplement is Out!

Every summer, birders anxiously await publication of the “Check-list Supplement” by the American Ornithological Society’s Committee on Classification and Nomenclature of North and Middle American Birds (a.k.a. the NACC). The supplement details revisions to the NACC’s Check-list Below is a brief rundown of those changes. (You can read the Supplement here, and you can read the committee members’ comments on the proposal here.)

Be sure to check out ABA’s annual Check-list Redux” in Birder’s Guide to Listing & Taxonomy. There, you’ll find photos, maps, and more detailed analysis of these changes. (You can see last year’s “Check-list Redux” here.)

You can read all the proposals on which the NACC voted this year at Species marked with asterisks (*) below are those which do not appear on the ABA Checklist, either because there are no currently accepted records in the ABA Area or because they are non-natives that have not yet been admitted to the list. Daggers (†) denote extinct species. Nowadays, it can be assumed that any change in taxonomy is due (at least partly) to analysis of new genetic data, so that is not always mentioned below. As a general policy, the NACC accepts as additions to its North American Check-list any species the ABA’s Checklist Committee adds to its list. Those changes are not listed here.

This year, the topics most likely to generate discussion are splits of Red Crossbill and Magnificent Hummingbird, a lump of Thayer’s and Iceland gulls, and a resolution of sorts into the taxonomic affiliations of the unique Yellow-breasted Chat.


Hello to the Cassia Crossbill


  • Red Crossbill (Loxia curvirostra)
  • Cassia Crossbill (Loxia sinesciuris)


In the Albion Mountains and South Hills of Cassia County, Idaho, there are no tree squirrels. Scientists have convincingly argued that this novel situation has allowed for the evolution of the area’s very own resident species of crossbill: Loxia sinesciuris, known as the Cassia Crossbill. Indeed, sinesciuris means “without squirrels”. In most of the Rockies, the seeds of lodgepole pine (Pinus contorta) are eaten, stored, and buried by tree squirrels such as the red squirrel (Tamiasciurus hudsonicus). In Cassia County, however, there are no squirrels, so the pines have been locked in an evolutionary arms race with but one main predator: the crossbill. Over thousands of years, the pine evolved bigger and harder cones to prevent the crossbill from accessing its seeds. And the crossbill evolved a bigger, deeper bill and stronger facial muscles in order to pull the seeds out of the cones.

This situation is remarkable because it happened in the presence of other crossbills. Two “types” of Red Crossbill (2 and 4), from which Cassia Crossbill was split, still commonly visit the area. But crossbill flocks are very cohesive and seem to form regional dialects quickly. The Cassia Crossbill not only has a different bill structure compared to the Red Crossbills with which it shares its range—but it also has different vocalizations. It seems that the evolution of Cassia Crossbill is a rare example of sympatric speciation in birds.

Good locations for seeking this species in the South Hills of south-central Idaho include Wahlstrom Hollow, Lower Penstemon Campground, Pettit Campground, the Diamondfield Jack parking area, and the Bostetter Guard Station. All are eBird hotspots. Separation of Cassia Crossbill from Red Crossbill is challenging, to say the least. Photos and audio recordings are certainly helpful, but note the following: Cassia Crossbill’s songs are more complex than those of Red Crossbill. Its dyup call has been described as dry, hollow, noticeably lower-pitched, and duller-sounding than the jip! of “Type 2” Red Crossbill; it may even recall the chup of an agitated American Robin. Cassia Crossbill’s bill is shorter and thicker than those of the Red Crossbill “types” in the area.

Finally, the Idaho Press Club lists CASH-uh (such as in the middle two words of “to cash a check”) as the preferred pronunciation of the county and, thus, the bird.


Goodbye to Thayer’s Gull

Larus thayeri Larus glaucoides thayeri

Thayer’s Gull is now treated as a subspecies of Iceland Gull. The authors of the Supplement state that more research is needed to determine if kumlieni should still be maintained as a valid subspecies; many birders and scientists believe it is instead a hybrid swarm between L. g. glaucoides and L. g. thayeri. Whatever you believe, your ABA Area list just decreased by one if you’ve seen both.

Thayer’s Gull in Illinois. Photo by Michael Retter.

Unfortunately, this lump breaks the NACC’s own “A=B+C Rule”, which states that unique English names should be used for splits and lumps so as to avoid confusion. When someone shouts “Iceland Gull” at the lakewatch this winter, what does it mean? Does the speaker intend a purely white-winged bird (glaucoides sensu stricto), as I would? L. g. glaucoides or L. g. kumlieni? Or glaucoides, kumlieni, or thayeri? It seems that Baffin Gull, Arctic Gull, Inuit Gull, Green-billed Gull, and Silver-winged Gull could have been workable and confusion-saving alternatives for naming the more-inclusive taxon.

Split of Magnificent Hummingbird

  • Rivoli’s Hummingbird (Eugenes fulgens)
  • Talamanca Hummingbird* (Eugenes spectabilis)

This split separates birds of southern Central America from those of Mexico, the U.S., and northern Middle America. Rivoli’s Hummingbird is found in pineoak woodlands from the southwestern U.S. south to northern Nicaragua; adult males have a peridot-colored (yellow-green) throat and blackish underparts. Talamanca Hummingbird is found in cloudforest and high oak forests of Costa Rica and western Panama; adult males have a turquoise- or teal-colored throat and dark green underparts. The latter was originally named “Admirable Hummingbird” by Robert Ridgway, but his suggestion was unheeded. Instead, Eugenes spectabilis has been named for the Talamanca Mountains of eastern Costa Rica.

This split raises the not particularly serious question of what to call a Berylline x Magnificent hybrid, which birders had playfully dubbed “Beryificent Hummingbird”. Berivoli’s? Riviline?


Split of Northern Harrier

  • Northern Harrier (Circus hudsonius)
  • Hen Harrier* (Circus cyaneus)

This split separates New World and Old World populations. The main effect on ABA Area birders is that of a scientific name change for Northern Harrier.

Adult male Hen Harriers are noticeably different compared to their Northern cousins. They are clean gray above (no dark mottling), have a larger black wingtip that covers six rather than five primary tips, and a medium gray (not black) trailing edge to the secondaries from above. They also tend to be clean white below. Females are difficult to tell apart. Juvenile Hen Harriers are strongly barred below on a rusty backgroundnot clear and rusty below as in Northern.

There are no accepted ABA Area records of Hen Harrier, but a severed wing discovered on Attu Island in 1999 may be from this species.


Split of Northern Shrike

  • Northern Shrike (Lanius borealis)
  • Great Gray Shrike* (Lanius excubitor)

This split separates New World and Old World populations. It seems that the Northern Shrikes from North America and northeast Asia are more closely related to Loggerhead Shrikes than they are to Great Gray Shrikes from western and central Eurasia. The effect on most ABA Area birders is that of a scientific name change for Northern Shrike.

The Northern Shrike race sibiricus nests in northeastern Siberia. As an adult, it differs from borealis in having pale lores and no white borders over the black mask. It also tends to be slightly paler gray above and lack a white spot on the lower eyelid. Identification of young birds seems less straightforward; juvenile sibiricus may have a pale border over the mask, but wholly pale lores may warrant scrutiny.

There are no accepted records of Great Gray Shrike from the ABA Area. In vol. 46, no. 2 of Western Birds, Gibson and Withrow write that sibiricus is “casual in [the western] Aleutians…[with] two specimens [at the University of Alaska Museum and] published photos [by] Schwitters.” Migrant “gray shrikes” in western Alaska deserve extra scrutiny.

LeConte’s Is One Word

  • Le Conte’s Thrasher ➛ LeConte’s Thrasher
  • Le Conte’s Sparrow ➛ LeConte’s Sparrow

Historical evidence strongly suggests that 19th-century entomologist John Lawrence LeConte, after whom the sparrow and the thrasher are named, did not usually write his last name with a space in it.

Split of Anas and New Sequence for the Dabbling Ducks

The genus Anas was found to be paraphyletic, so it has now been split into four genera: Sibirionetta (Baikal Teal), Spatula (shovelers, including false teal), Mareca (Gadwall, Falcated Duck, and wigeons), and Anas (mallards, pintail, and true teal). Surely unsurprising to some birders familiar with the appearance of many hybrid dabbling ducks will be that among these species, Baikal Teal’s lineage is distinct and split off first from the others. Many male hybrid dabbling ducks (for instance, Mallard x Gadwall, Gadwall x Northern Shoveler, American Wigeon x Green-winged Teal, Blue-winged Teal x Green-winged Teal) display a facial pattern strikingly similar to that of Baikal Teal, and this is believed to be an ancestral trait that sometimes reappears with hybridization. The new sequence and scientific names are as follows.

• Baikal Teal (Anas formosa Sibirionetta formosa)

  • • Garganey (Anas querquedulaSpatula querquedula)
    • Blue-winged Teal (Anas discorsSpatula discors)
    • Cinnamon Teal (Anas cyanoptera Spatula cyanoptera)
    • Northern Shoveler (Anas clypeata Spatula clypeata)
    • Gadwall (Anas strepera Mareca strepera)
    • Falcated Duck (Anas falcata Mareca falcata)
    • Eurasian Wigeon (Anas penelope Mareca penelope)
    • American Wigeon (Anas americana Mareca americana)
    • Laysan Duck (Anas laysanensis)
    • Hawaiian Duck (Anas wyvilliana)
    • Eastern Spot-billed Duck (Anas zonorhyncha)
    • Mallard (Anas platyrhynchos)
    • American Black Duck (Anas rubripes)
    • Mottled Duck (Anas fulvigula)
    • White-cheeked Pintail (Anas bahamensis)
    • Northern Pintail (Anas acuta)
    • Green-winged Teal (Anas crecca)


Goodbye, Chen

The genus Anser was found to be paraphyletic, so the “white goose” genus, Chen, has been lumped into the “gray goose” genus, Anser. The sequence and scientific names for the Anser geese are now as follows.

• Emperor Goose (Chen canagicus Anser canagicus)
• Snow Goose (Chen caerulescens Anser caerulescens)
• Ross’s Goose (Chen rossii Anser rossii)
• Graylag Goose (Anser anser)
• Greater White-fronted Goose (Anser albifrons)
• Lesser White-fronted Goose (Anser erythropus)
• Taiga Bean-Goose (Anser fabalis)
• Tundra Bean-Goose (Anser serrirostris)
• Pink-footed Goose (Anser brachyrhynchus)


Sparrows, Spindalises, Yellow-breasted Chat, and a number of Tropical Groups Get Their Own Families and a New Sequence

Yellow-breasted Chat in South Dakota. Photo by Michael Retter.

Studies of higher-level taxonomy in the perching birds has revealed deep evolutionary divisions, warranting that these groups be put in their own families. Birders and ornithologists have long known that Yellow-breasted Chat is an odd bird, and now we have the proof. A warbler it is not.

Beware the similarity between the words Icteridae (the New World Blackbird family) and Icteriidae (the Yellow-breasted Chat family)—the latter has only an extra i to differentiate it! As for pronunciation, I imagine the blackbird family will be most commonly pronounced ICK-ter-ih-day, and the Yellow-breasted Chat family ick-TEHR-ee-ih-day.

  • Rhodinocichlidae (Thrush-tanagers)
  • Emberizidae (Old World Buntings)
  • Passerellidae (New World Sparrows and Towhees)
  • Calyptophilidae (Chat-tanagers)
  • Phaenicophilidae (Hispaniolan Tanagers)
    Neospingidae (Puerto Rican Tanager)
  • Spindalidae (Spindalises)
  • Zeledoniidae (Wrenthrushes)
  • Teretistridae (Cuban Warblers)
  • Icteriidae (Yellow-breasted Chat)
  • Icteridae (New World Blackbirds)
  • Parulidae (New World Warblers)
  • Mitrospingidae (Dusky-faced Tanager and three South American Species:

Olive-backed Tanager, Red-billed Pied Tanager, and Olive-green Tanager)

  • Cardinalidae (Cardinals and Allies)
  • Thraupidae (True Tanagers)


Goodbye, Procelsterna

  • Blue-gray Noddy (Procelsterna ceruleaAnous ceruleus)

The noddy genus Anous was found to be paraphyletic, so the genus Procelsterna has been absorbed into it. Blue-gray Noddy occurs in Hawaiian waters.


Goodbye, Mesophoyx

  • Intermediate Egret (Mesophoyx intermediaArdea intermedia)

The genus Ardea was found to be paraphyletic with respect to Mesophoyx.


New Genus for Yellow-fronted Canary

  • Yellow-fronted Canary in Kona, Hawaii. Photo by Michael Retter.

    Serinus mozambicusCrithagra mozambica

Established in Hawaii, Yellow-fronted Canary has been moved from the genus Serinus to Crithagra.


New Sequence for Sandpipers


Upland Sandpiper

Bristle-thighed Curlew


Little Curlew

Eskimo Curlew

Long-billed Curlew

Far Eastern Curlew

Slender-billed Curlew

Eurasian Curlew
Bar-tailed Godwit
Black-tailed Godwit
Hudsonian Godwit
Marbled Godwit
Ruddy Turnstone
Black Turnstone
Great Knot

Red Knot



Broad-billed Sandpiper

Sharp-tailed Sandpiper

Stilt Sandpiper
Curlew Sandpiper

Temminck’s Stint

Long-toed Stint

Spoon-billed Sandpiper

Red-necked Stint



Rock Sandpiper

Purple Sandpiper

Baird’s Sandpiper
Little Stint

Least Sandpiper
White-rumped Sandpiper

Buff-breasted Sandpiper

Pectoral Sandpiper
Semipalmated Sandpiper
Western Sandpiper

Short-billed Dowitcher

Long-billed Dowitcher

Jack Snipe
Eurasian Woodcock

American Woodcock

Solitary Snipe

Pin-tailed Snipe
Common Snipe

Wilson’s Snipe

Terek Sandpiper

Common Sandpiper

Spotted Sandpiper

Green Sandpiper

Solitary Sandpiper

Gray-tailed Tattler

Wandering Tattler

Lesser Yellowlegs


Spotted Redshank

Common Greenshank

Greater Yellowlegs

Common Redshank

Wood Sandpiper

Marsh Sandpiper

Wilson’s Phalarope

Red-necked Phalarope

Red Phalarope


New Sequence for Finch Genera







































Changes to Sequence and Subfamily Classification within the New World Blackbirds (Icteridae)

  • Xanthocephalinae (Yellow-headed Blackbird)
  • Dolichonychinae (Bobolink)


  • Sturnellinae (Meadowlarks)



  • Ambylcercinae* (Yellow-billed Cacique)


  • Cacicinae* (Oropendolas and true caciques)




  • Icterinae (New World Orioles)


  • Agelaiinae (New World Blackbirds)











Notable Changes That Were Not Accepted

  • Split of Willet into Eastern and Western willets
  • Two-way split of Bell’s Vireo
  • Two-way split of Brown Creeper
  • Three-way split of Yellow-rumped Warbler
  • Lumping of Yellow-eyed and Dark-eyed juncos
  • Lumping of Common and Hoary redpolls
  • Changing English name of Ring-necked Duck to Ring-billed Duck


On the Horizon

Topics which may be considered next year include splitting Naumann’s Thrush from Dusky Thrush, splitting White-winged Scoter, splitting Cuban from Eastern Meadowlark, lumping Gilded Flicker back into Northern Flicker, and lumping Bicknell’s Thrush back into Gray-cheeked Thrush. Major revisions of higher-level hummingbird and vireo taxonomy are also anticipated.




(Asterisks are no longer used to label species not found in the ABA Area; instead, they denote species that are not found in the the NACC Area.)


Split of Emerald Toucanet

  • Northern Emerald-Toucanet (Aulacorhynchus prasinus)
  • Southern Emerald-Toucanet* (Aulacorhynchus albivitta)

Northern Emerald-Toucanet is found from Mexico south to the Darién Gap; it includes three rather different-looking subspecies groups: prasinus, wagleri (“Wagler’s Toucanet”), and caeruleogularis (“Blue-throated Toucanet”). Southern Emerald-Toucanet is found in South America.


Split of Prevost’s Ground-Sparrow

• White-faced Ground-Sparrow (Melozone biarcuata)
Cabanis’s Ground-Sparrow (Melozone cabanisi)

White-faced Ground-Sparrow is resident from Chiapas south to western Honduras; it has an extensively white face. Cabanis’s Ground-Sparrow is endemic to central Costa Rica; it has a complex pattern of reduced white on the face.

Split of Yellow-eyed Junco

  • Yellow-eyed Junco (Junco phaeonotis)
  • Baird’s Junco (Junco bairdi)

Baird’s Junco. Photo by Michael Retter.

Baird’s Junco, endemic to the highlands of southern Baja California Sur, has been split from the other populations of Yellow-eyed Junco. Baird’s averages browner on the flanks and duller on the back. It also tends to have a more complex song.



Genus Change for Violet-bellied Hummingbird

  • Damophila julie Juliamyia julie

The genus Damophila was coined in 1832 to describe a species of “micro” moth. It was not until 1854 that the same word was used to describe a hummingbird. According to the Principle of Priority, Damophila is not available for the hummingbird genus, which must be renamed. That “new” hummingbird genus is Juliamyia.



New Genus for Red-breasted Blackbird

  • Sturnella militarisLeistes militaris


The red-breasted meadowlarks of South America and southern Central America now have their own genus. Note that Red-breasted Blackbird is called Red-breasted Meadowlark by the IOC.



New Genus for Cuban Blackbird


  • Dives atroviolaceusPtiloxena atroviolacea


Addition of Mangrove Rail to the Check-list

The large rails along the Pacific Coast of Central America (north to El Salvador) are considered to belong to Mangrove Rail (Rallus longirostris), which was until recently lumped into Clapper Rail.


Greenland Records

Nine species were added to the Check-list because of records in Greenland. They are:

  • Ruddy Shelduck (Tadorna ferruginea)
  • Western Water Rail (Rallus aquaticus)
  • Oriental Plover (Charadrius veredus)
  • Rook (Corvus frugilegus)
  • Hooded Crow (Corvus cornix)
  • Eurasian Blackcap (Sylvia atricapilla)
  • White’s Thrush (Zoothera aurea)
  • Meadow Pipit (Anthus pratensis)
  • Lesser Redpoll (Acanthis cabaret)


Additional Proposals Not Accepted

  • Split of Grayson’s Robin from Rufous-backed Robin
  • Split of Wagler’s and Blue-throated Toucanets from Northern Emerald-Toucanet
  • Split of Yellow-eyed Junco into Guatemalan and Mexican juncos
  • Wagler’s and Blue-throated toucanets split from Emerald Toucanetboth now contained within Northern Emerald-Toucanet
  • Split of Guatemalan Flicker from Northern Flicker