The eBird Taxonomy

Updated 15 Aug 2019 — eBird Taxonomy v2019

The eBird Taxonomy is a hierarchical approach to creating a species list for data entry and listing purposes across the world. You can download an excel version of the eBird taxonomy at the bottom of the page. Since understanding exactly what is meant by every bird species or taxon on a given list is an essential part of reporting your sightings, we detail our approach below to help clarify any questions.

Download

To download the eBird taxonomy, the Clements taxonomy, or a merged version, please visit the Clements/eBird checklist download page. As explained below, the eBird Taxonomy includes all taxa available in eBird; the Clements Checklist includes just species, subspecies groups, and subspecies (subspecies are not available in the eBird taxonomy), and the eBird/Clements Checklist includes both lists merged together. This last option is especially useful for determining what subspecies comprise each subspecies group, for example.

eBird Taxonomy — Categories

The eBird taxonomy is much more than a list of species. It includes every field-identifiable taxon that could be relevant for birders to report. The taxonomic categories are each dealt with differently in eBird output and the eight categories are clearly indicated in the downloadable file below (a ninth category, Clements ssp., is available only in the Clements Checklist). The eight eBird categories are as follows:

• Spuh:  Genus or identification at broad level, e.g., swan sp. Cygnus sp. 
• Slash: Identification to Species-pair, e.g., Tundra/Trumpeter Swan Cygnus columbianus/buccinator 
• Species: e.g., Tundra Swan Cygnus columbianus 
• ISSF or Identifiable Sub-specific Group: Identifiable subspecies or group of subspecies, e.g., Tundra Swan (Bewick’s) Cygnus columbianus bewickii or Tundra Swan (Whistling) Cygnus columbianus columbianus
• Hybrid: Hybrid between two species, e.g., Tundra x Trumpeter Swan (hybrid)
  Intergrade: Hybrid between two ISSF (subspecies or subspecies groups), e.g., Tundra Swan (Whistling x Bewick’s) Cygnus columbianus columbianus x bewickii
• Domestic: Distinctly-plumaged domesticated varieties that may be free-flying (these do not count on personal lists) e.g., Mallard (Domestic type)
• Form: Miscellaneous other taxa, including recently-described species yet to be accepted or distinctive forms that are not universally accepted, e.g., Red-tailed Hawk (abieticola), Upland Goose (Bar-breasted)

eBird Taxonomy — Species

Our species and subspecies taxonomy follows the Clements Checklist. The Clements Checklist is a global bird taxonomy which follows regional authorities. In the New World, the Clements Checklist largely defers to the two AOS committees–the North American Classification Committee (NACC) and the South American Classification Committee (SACC)–with the goal of near-complete compliance. The few departures from their taxonomy and nomenclature tend to be in the handful of the cases where the two committees are not in agreement, or where one or both committees makes a taxonomic or nomenclatural decision that is at odds with prevailing usage elsewhere in the world. In the latter case, this most often applies to very rare vagrants in North America (e.g., Siberian Stonechat, Dusky Thrush). All such departures are listed in detail in Appendix A (NACC) and Appendix B (SACC).

The eBird taxonomy (v2018) is current with Clements v2018 which is itself current with the 60th supplement to the AOS-NACC Check-List and the AOS-SACC Check-List through 6 Jun 2019 (The NACC issues updates once a year in August, whereas the SACC updates their taxonomy continually.)

Clements updates occur once a year in the late summer/autumn, and are documented in full, and can be downloaded directly here. The downloadable list is very useful since this checklist includes a description of the world range for each species and subspecies as well. eBird taxonomic updates coincide with the Clements updates in August.

eBird Taxonomy — Subspecies, Groups, and ISSFs

The Clements checklist includes identifiable groups, which we also use in eBird. Identifiable groups–which eBird refers to as ISSF (Identifiable Subspecific Form)–are taxonomic units below the species level that follow subspecific boundaries as defined by the Clements checklist. These may be a formally described subspecies,

Junco hyemalis aikeni……Dark-eyed Junco (White-winged)

a subspecies pair:

Junco hyemalis hyemalis/carolinensis…..Dark-eyed Junco (Slate-colored)

or a group of subspecies which we define:

Junco hyemalis [oreganus Group]….Dark-eyed Junco (Oregon)

These groups or ISSFs allows eBirders to make note of identifiable differences (which may be helpful if the species are later split) to study the distribution and abundance of different subspecific forms where they both occur. We encourage eBirders to use these groups to report whenever possible; note that you can always add any species or group to your checklist by clicking “rare species” and using the “Add a species” box.

The Clements checklist is a work in progress. New species are described each year and new splits are justified in print almost weekly. In addition to keeping up with these rapid advances in bird taxonomy, the Clements team also endeavors to add a number of new subspecies groups to the checklist in the coming years. Assistance is welcome, especially from South America and the Old World.

eBird Taxonomy — beyond Clements

In addition to the formal taxonomic concepts that are included in the Clements Checklist, the eBird taxonomy includes an expanded list of other bird taxa that birders may report. Like the Clements list, we have rules governing the nomenclature and taxonomic placement of these birds, so that they appear in predictable places on any bird list. These additional categories of bird taxa are listed below, and are identified accordingly in our eBird taxonomy.

Hybrids and intergrades

We have made an effort to include many known hybrids that occur in the wild. While this is not a list of every single hybrid combination reported, we have tried to include those that are frequent enough and distinctive enough that they might be reported by birders. These range from the common combinations like “American Black Duck x Mallard” and “Western x Glaucous-winged Gull” to considerably rarer combinations like “Magnificent x Berylline Hummingbird” and “White-throated Sparrow x Dark-eyed Junco.” Note that the hybrid names always follow phylogenetic sequence, with the first species in sequence coming first in the hybrid name. Hybrids are listed immediately following the ISSF groups in the second parent species in the sequence. All hybrids are followed by the parenthetical note “(hybrid)”–thus you can review all hybrids by searching for (hybrid) within the “Find a species” text box during checklist entry.

We also include intergrades, where hybridization between two subspecies or ISSFs produces an identifiable cross. For example, since the two forms of Green-winged Teal (American and Eurasian) are distinctive and each is treated as an ISSF in the eBird taxonomy, we consider the hybrid result of a mixed pairing to be an intergrade.

Spuhs (and slashes)

Spuhs? What is a spuh, you ask? For difficult to identify groups (like flycatchers) or distant birds (hawkwatchers regularly cope with this problem), birders will often record their identifications only to the genus level, or to some other level above species. “Spuh” is our affectionate term for birds not identified to the species level. Examples include: Empidonax sp., scoter sp., Accipiter sp., or duck sp. Many birders keep track of these sightings, and they can be tracked in eBird as well.

Note that we have two ways of tracking spuhs. Some are listed with the group name and “sp.” But when there are only two members of a species pair are possible, we instead have opted to list these with a slash. For example, we do not use “murre sp.” but instead list “Common/Thick-billed Murre.” The often-used “dowitcher sp.” is instead listed as “Short-billed/Long-billed Dowitcher.” Other useful listings include: Greater/Lesser Yellowlegs, Semipalmated/Western Sandpiper, and Parasitic/Pomarine Jaeger. We refer to each of these as a slash in our taxonomy.

You can review the available spuhs by searching for “sp.” in the “Find a species” box and you can review all slash combos by searching for “/”.

Domestics

Some species such as Mallard, Graylag Goose, or Wild Turkey have a long history of domestication, and their free-flying progeny are sometimes encountered in the field. We allow these birds to be reported in eBird using Mallard (Domestic type), Graylag Goose (Domestic type), and Wild Turkey (Domestic type). Note however that the domestic types in eBird are phenotypes, and thus are field identifiable as birds of domestic origin by virtue of their white plumage, large size, puffy rear ends (e.g., Mallards) or other traits that are not typical of wild populations. This option *should not* be used to report birds that are identical to wild birds but that you presume to be escapees. Importantly, our “domestic type” is a distinct lineage for these birds and not a value judgment of whether you believe it recently escaped from a cage or pen. This is often mis-used in eBird, so please try to understand this distinction before reporting domestic types in eBird. domestics are generally not counted on eBird lists, but there are two exceptions. Rock Pigeon (Feral Pigeon) is used to represent the wild, free-flying pigeons that occur in cities worldwide, and it distinct from Rock Pigeon (Wild type), which is much rarer and of conservation status in many regions (read more here). Muscovy Duck (Established Feral) is to be used for feral type birds (white, or blotchy, often with oversized red warty protuberances on the face) that are considered established parts of the avifauna in areas such as Florida; the Muscovy Duck is unusual since it also has an option for Muscovy Duck (Domestic type) which does not count on lists but is phenotypically identical.

Forms

In some cases, there are additional bird entities that can’t be described with a formal scientific name. These may include new species (or suspected new species) that birders are already reporting and documenting. Since the Clements Checklist will not add them until the formal description has appeared in a peer-reviewed paper, it can be years (or decades) until the species would be available via that list. Collecting data on these entities is important, so we include them as a “form”, which is a catch-all for additional birds which we want birders to report, but which do not yet have a formal scientific name (some of them may never have such a name). We expect to expand this list in the future to include other yet-to-be-described species.

These forms are listed in Appendix C.

Alternate common names

We support 50+ alternate common names, including Spanish, French, Thai, Russian, Spanish, Chinese, Turkish, Hebrew and many more. Please see more at Common Name Translations in eBird.

A work in progress

Both the Clements taxonomy and the eBird taxonomy are works in progress. If you notice any species, subspecies, hybrid, or “spuh” that is conspicuously absent, please let us know with an email to ebird@cornell.edu. Furthermore, should you find any errors in spelling, nomenclature, taxonomy, or sequence, please do let us know as well.

Recent updates: The eBird taxonomy is updated once a year. To see summaries of the recent updates, you can read the stories here:

• June 2010 update
• January 2011 update
• August 2011 update
• August 2012 update
• September 2013 update
• August 2014 update
• August 2015 update
• August 2016 update
• August 2017 update
• August 2018 update
• August 2019 update

APPENDIX A

The Clements Checklist follows the two AOS committees, NACC and SACC, but there are a small number of cases where the committees are not in alignment. Since the American Birding Association (ABA) and many other groups follow the species taxonomy of the NACC, we document these departures in detail below. Note that minor differences in checklist order occur as well, but are not detailed in full. Appendix B documents departures from the SACC.

eBird/Clements departures from the AOS North American Classification Committee (NACC) Check-List are detailed in full below:

SPLITS

• Comb Duck (Sarkidiornis melanotos): We split Knob-billed Duck (Sarkidiornis melanotos), of the Old World, and Comb Duck (Sarkidiornis sylvicola), of the New World, as separate species. Neither AOS committee has yet considered a proposal for these species, although the AOS-SACC is currently reviewing this species.
• Mallard (Anas platyrhynchos): We split Mexican Duck (Anas diazi), which occurs in Mexico and in the United States along the Mexican border, from the widespread Mallard (Anas platyrhynchos). Genetic divergence of Mexican Duck from Mallard is at comparable levels to other similar taxa that are recognized as species, such as American Black Duck Anas rubripes and Mottled Duck Anas fulvigula and hybridization between Mallard and Mexican Duck has not been demonstrated to occur at higher levels than between Mallard and other species in the Mallard complex. AOS-NACC did recently (2018) consider this proposal but did not elect to split and may reconsider this decision for 2020.
• Paltry Tyrannulet (Zimmerius vilissimus): We follow AOS-SACC in splitting Paltry Tyrannulet in to four species: Guatemalan Tyrannulet (Zimmerius vilissimus), Mistletoe Tyrannulet (Zimmerius parvus), Spectacled Tyrannulet (Zimmerius improbus), and Venezuelan Tyrannulet (Zimmerius petersi). Guatemalan Tyrannulet occurs in the highlands of s. Mexico, Guatemala, Honduras, and El Salvador, Mistletoe Tyrannulet occurs primarily in lowland areas from Belize and s. Guatemala to w. Colombia, Spectacled Tyrannulet occurs in montane areas of n. Colombia and w. Venezuela, and Venezuelan Tyrannulet occurs in the coastal ranges of northern Venezuela. AOS-NACC has yet to consider a proposal to split these species.
• Purple Swamphen (Porphyrio porphyrio): Although considered a single species by NACC, it has recently been recognized that there are six species within Purple Swamphen, occurring roughly from west to east in the Old World as follows: Western Swamphen (Porphyrio porphyrio); African Swamphen (Porphyrio madagascariensis); Gray-headed Swamphen (Porphyrio poliocephalus); Black-backed Swamphen (Porphyrio indicus); Philippine Swamphen (Porphyrio pulverulentus); and Australasian Swamphen (Porphyrio melanotus). The species was recently added to the North American list because of an established, introduced population of Gray-headed Swamphen in Florida. Since that time, a vagrant African Swamphen has also appeared on Bermuda. The NACC considered this split in 2016 but chose not to split Purple Swamphen at this time. AOS-NACC did recently consider this proposal but did not elect to split.
• Fork-tailed Swift (Apus pacificus) is considered a single species by the AOU, but split into four species by most other authorities, including eBird/Clements. Of those, only Pacific Swift (Apus pacificus) has occurred in North America (as a vagrant to Alaska). The other three species are Salim Ali’s Swift (Apus salimalii), Blyth’s Swift (Apus leuconyx), and Cook’s Swift (Apus cooki), all of which are non-migratory and unlikely to occur in North America. AOS-NACC did consider this proposal but did not elect to split.
• Stonechat (Saxicola torquatus) is considered a single species by the AOS, but split into three species by the British Ornithologists’ Union (BOU) and others. We follow the three-way split in eBird, and thus have: European Stonechat (Saxicola rubicola), African Stonechat (Saxicola torquatus), and Siberian Stonechat (Saxicola maurus). All North American records pertain to Siberian Stonechat. Note that some authorities (e.g., IOC) further split Stejneger’s Stonechat (Saxicola [m.] stejnegeri), and if that is followed, North American records would presumably be of this taxon, although not all records have been confirmed as stejnegeri. AOS-NACC did recently consider this proposal but did not elect to split.
• Hwamei (Garrulax canorus): In accord with most authorities, Chinese Hwamei (Garrulax canorus) and Taiwan Hwamei (Garrulax taewanus) are split by eBird, resulting in the common name difference between the NACC and eBird/Clements. AOs-NACC recently (2019) considered this split and elected not to adopt it.
• Dusky Thrush (Turdus naumanni): In accord with the British Ornithologists’ Union (BOU) and others, we recognize the split of Dusky Thrush (Turdus eunomus) and Naumann’s Thrush (T. naumanni), which the AOU retains as a single, lumped species: Dusky Thrush (Turdus naumanni). These two very different looking thrushes have both been reported from the AOU Area, although the two or three reports of Naumann’s Thrush have not been documented by a specimen or photograph and thus are only considered hypothetical.

COMMON NAMES

• Eurasian Marsh-Harrier (Circus aeruginosus): In accord with prevailing usage elsewhere in the world, we use the name Eurasian Marsh-Harrier rather than Western Marsh Harrier. There are only a couple vagrant records from the Caribbean, giving the NACC a tenuous claim on a rarely-used name.
• Water Rail (Rallus aquaticus): The NACC added this species in 2017 based on records from Greenland, and opted to use the novel, hyphenated English names Western Water-Rail for Rallus aquaticus and Eastern Water-Rail for the extralimital Rallus indicus. eBird/Clements continues to use the more widely established names of Water Rail and Brown-cheeked Rail, respectively.
• Eurasian Moorhen (Gallinula chloropus): The Common Moorhen (Gallinula chloropus) was recently split into Old World and New World forms, Common Moorhen (Gallinula gallinula) and Common Gallinule (Gallinula galeata), respectively. These two species are genetically very different but almost identical in the field (although calls differ). We use the name Eurasian Moorhen to better describe its range and to avoid confusion with the previously lumped species (Common Moorhen sensu lato) species, which has a nearly worldwide distribution. [Note: it is very odd that NACC has chosen to refer to one of these species as gallinule and the other as moorhen. Globally, most Gallinula are known as moorhens.]

SCIENTIFIC NAMES​

• Orinoco Goose (Oressochen jubatus): We follow SACC in using this name; NACC uses Neochen jubata.
• Paint-billed Crake (Mustelirallus erythrops): In accord with the most recent science, now adopted by SACC, we use the scientific name Mustelirallus erythrops for Paint-billed Crake, instead of Neocrex erythrops used by NACC.
• Colombian Crake (Mustelirallus erythrops): In accord with the most recent science, now adopted by SACC, we use the scientific name Mustelirallus colombianus for Colombian Crake, instead of Neocrex colombiana used by NACC.
• In accord with SACC, we revise the genus on three antbirds:
  • Chestnut-backed Antbird (Poliocrania exsul): NACC uses Mymeciza exsul.
  • Dull-mantled Antbird (Sipia laemosticta): NACC uses Mymeciza laemosticta.
  • Zeledon’s Antbird (Hafferia zeledoni): NACC uses Mymeciza zeledoni
• Pale-eyed Pygmy-Tyrant (Atalotriccus pilaris): In accord with SACC, we consider Pale-eyed Pygmy-Tyrant to be in the genus Atalotriccus.
• Green Manakin (Xenopipo holochlora): In accord with SACC, we consider Green Manakin to be in the genus Xenopipo.
• Dwarf Jay (Cyanolyca nanus): We follow Dickinson and Christidis (2014) in correcting this scientific name, while NACC still uses Cyanolyca nana.
• Greater Necklaced Laughingthrush (Ianocincla pectoralis): NACC considers this Garrulax pectoralis.

SEQUENCE

• The sequence of hawks and eagles differs substantially between eBird vs. NACC. eBird follows the most current research used by SACC, but needed to apply it worldwide. For this reason, Bald Eagle is placed below Accipiters on the eBird list (but not on the NACC list). It is our hope that NACC soon will follow this newer research. It was partially adopted in 2015 when White-tailed Hawk was moved by NACC to the Genus Geronautes, in accord with eBird and SACC.
• The sequence of some sparrows (towhees, Zonotrichia) has changed to follow the more recent phylogenies of American Emberizids already adopted by SACC. We expect NACC to address these same revisions in the near future.

APPENDIX B — SACC DEPARTURES

The below documentation discusses inconsistencies with the SACC Check-List as of to July 2019.

SPLITS

• Comb Duck (Sarkidiornis melanotos): See above; SACC and NACC use the same taxonomy for this species.
• Ruddy Duck (Oxyura jamaicensis): We follow NACC in considering the Ruddy Duck (Oxyura jamaicensis) and Andean Duck (Oxyura ferruginea) to be separate species. Ruddy Duck occurs only in North America and Andean Duck only in South America. Note that we include the controversial taxon andina, of central Colombia, within Andean Duck.
• Barolo Shearwater (Puffinus baroli): The SACC species Little Shearwater (Puffinus assimilis) is a complex of small shearwaters that have recently been proven to not necessarily be each other’s closest relatives (e.g., Austin et al. 2004). The taxonomy adopted by Clements/eBird and NACC best matches that used by Onley and Scofield (2007. Albatrosses, Petrels and Shearwaters of the World). In addition to other splits from both Audubon’s and Little Shearwater for areas outside of North America (e.g., we recognize Persian and Tropical Shearwaters), we grant species status to each of the two North Atlantic forms that were previously considered Little Shearwater: Barolo Shearwater (Puffinus baroli) and Boyd’s Shearwater (Puffinus boydi). The former breeds on the Azores, Madeira, and several other islands off the Mediterranean and North Africa and is the form that has strayed to North America. The latter (Boyd’s Shearwater) breeds on the Cape Verde Islands and is yet unknown from North America, but might occur in the future. Note that the BOU merges Boyd’s and Barolo under a single species: Macaronesian Shearwater (Puffinus baroli).
• Great-winged Petrel (Ptrerodroma macroptera): A recent paper supported this split and recognizes Gray-faced Petrel (Pterodroma gouldi), which breeds on islands off the North Island of New Zealand, as distinct from Great-winged Petrel (Pterodroma macroptera), which breeds on islands in the southern oceans. Only Gray-faced Petrel has occurred (as a vagrant) in North America, where there are several California records. In South America, there is one record of Gray-faced Petrel from Chile and at least one record of Great-winged Petrel from Brazil. AOS-NACC has split them, but AOS-SACC has yet to consider a proposal to split these species.
• Band-rumped Storm-Petrel (Oceanodroma castro): Although it does not result in a name change or any change in the records yet, eBird and Clements have begun to recognize that Band-rumped Storm-Petrel is actually a cryptic complex of several species. Only Cape Verde Storm-Petrel (O. jabejabe) and Monteiro’s Storm-Petrel (O. monteiroi) have been recognized thus far, but ultimately at least one other Atlantic taxon is likely to be split from Band-rumped. the form, Band-rumped Storm-Petrel (Grant’s) is yet undescribed, but increasingly well-known in its east Atlantic breeding areas and its vocal differences have been described by the Sound Approach team. In addition, at least two and maybe more Pacific taxa (including the Galapagos form, also available in eBird) surely will be split. Debate continues about which form(s) occur(s) in United States waters. While this has no effect on current lists (since only nominate and the undescribed taxa are yet documented or believed to visit North American waters), it is worth keeping in mind that the eBird/Clements definition of Band-rumped Storm-Petrel is different from that of the AOS. AOS-NACC formally recognized O. monteiroi (and presumably O. jabejabe) but AOS-SACC has yet to formally consider a proposal to split these species.
• Whiskered Flycatcher: We consider Sulphur-rumped and Whiskered flycatchers to be different species, but SACC has yet to adopt this split, considering both under a single species Sulphur-rumped Flycatcher (Myiobius barbatus).

COMMON NAMES

• Moseley’s Rockhopper Penguin (Eudyptes moseleyi): SACC uses the name Rockhopper Penguin, in accord with this proposal. We use Moseley’s Rockhopper Penguin which is more established globally.
• Southern Rockhopper Penguin (Eudyptes chrysocome): SACC uses the name Tristan Penguin, in accord with this proposal. We use Southern Rockhopper Penguin which is more established globally.
• For a suite of species in the genera Columba, Metriopelia, and Uropelia, we use the hyphenated name Ground-Dove (following NACC spelling for Columba) while SACC opts for the unhyphenated form, Ground Dove.
• White-winged Parakeet (Brotogeris versicolurus): SACC uses the common name Canary-winged Parakeet; White-winged Parakeet is in accord with NACC.
• Tawny-faced Gnatwren (Microbates cinereiventris): SACC uses Half-collared Gnatwren; Tawny-faced Gnatwren is in accord with NACC.
• Southern Masked-Weaver (Ploceus velatus): SACC uses African Masked Weaver; Southern Masked-Weaver is in much wider use in the species’ home range.

SCIENTIFIC NAMES

• European Greenfinch (Chloris chloris) – SACC uses scientific name Carduelis chloris

APPENDIX C — eBird “forms”

The following birds, listed in the eBird taxonomy as “forms”, are not formally recognized by the Clements taxonomy and thus do not have official taxonomic status and do not have official taxonomic names. In some cases we create a name, while in others we use published names that have yet to gain formal acceptance. At least a few of these have been described and may soon be updated to species rank. These are listed in full below:

Brant (Gray-bellied) Branta bernicla (Gray-bellied)
Upland Goose (White-breasted) Chloephaga picta (White-breasted)
Upland Goose (Bar-breasted) Chloephaga picta (Bar-breasted)
Flightless Steamer-Duck (Chiloe form) Tachyeres pteneres [undescribed form]
Rock Pigeon (Wild type) Columba livia (Wild type)
Palawan Cuckoo-Dove (undescribed form) Macropygia [undescribed form]
Timor Nightjar (undescribed form) Caprimulgus [undescribed Timor form]
Maranhao Hermit (unrecognized species) Phaethornis maranhaoensis [unrecognized species]
Crowned Woodnymph (Violet-crowned Woodnymph) Thalurania colombica (Violet-crowned Woodnymph)
Crowned Woodnymph (Green-crowned Woodnymph) Thalurania colombica (Green-crowned Woodnymph)
Guanacaste Hummingbird (unrecognized species) Amazilia alfaroana [unrecognized species]
Hawaiian Coot (Red-shielded) Fulica alai (Red-shielded)
Hawaiian Coot (White-shielded) Fulica alai (White-shielded)
American Coot (Red-shielded) Fulica americana (Red-shielded)
American Coot (White-shielded) Fulica americana (White-shielded)
Slate-colored Coot (White-billed) Fulica ardesiaca (White-billed)
Slate-colored Coot (Yellow-billed) Fulica ardesiaca (Yellow-billed)
Great Nicobar Crake (undescribed form) Rallina [undescribed form]
Whimbrel (White-rumped) Numenius phaeopus phaeopus/alboaxillaris/variegatus
Rock Sandpiper (quarta/tschuktschorum/couesi) Calidris ptilocnemis quarta/tschuktschorum/couesi
Brown-hooded Gull (White-winged) Chroicocephalus maculipennis (White-winged)
Brown-hooded Gull (Dark-winged) Chroicocephalus maculipennis (Dark-winged)
Iceland Gull (thayeri/kumlieni) Larus glaucoides thayeri/kumlieni
Iceland Gull (glaucoides/kumlieni) Larus glaucoides glaucoides/kumlieni
Lesser Black-backed Gull (taimyrensis) Larus fuscus taimyrensis
Lesser Black-backed Gull (intermedius/graellsii) Larus fuscus intermedius/graellsii
New Caledonian Storm-Petrel (undescribed form) Fregetta [undescribed form]
Leach’s/Townsend’s Storm-Petrel (dark-rumped) Oceanodroma leucorhoa/socorroensis (dark-rumped)
Leach’s/Townsend’s Storm-Petrel (white-rumped) Oceanodroma leucorhoa/socorroensis (white-rumped)
Band-rumped Storm-Petrel (Madeiran) Oceanodroma castro castro
Band-rumped Storm-Petrel (Grant’s) Oceanodroma castro [undescribed form]
Band-rumped Storm-Petrel (Darwin’s) Oceanodroma castro bangsi
Black-capped Petrel (White-faced) Pterodroma hasitata (White-faced)
Black-capped Petrel (Dark-faced) Pterodroma hasitata (Dark-faced)
Gough Prion (undescribed form) Pachyptila [undescribed form]
Galapagos Shearwater (Dark-winged) Puffinus subalaris (Dark-winged)
Galapagos Shearwater (Light-winged) Puffinus subalaris (Light-winged)
Great Cormorant (Dark-breasted) Phalacrocorax carbo carbo/sinensis
Imperial Cormorant (Blue-eyed) Phalacrocorax atriceps (Blue-eyed)
Imperial Cormorant (King) Phalacrocorax atriceps (King)
Great Blue Heron (Wurdemann’s) Ardea herodias (Wurdemann’s)
Variable Hawk (Puna) Geranoaetus polyosoma (Puna)
Variable Hawk (Red-backed) Geranoaetus polyosoma (Red-backed)
Red-tailed Hawk (abieticola) Buteo jamaicensis abieticola
Red-tailed Hawk (calurus/abieticola) Buteo jamaicensis calurus/abieticola
Elgin Buzzard (undescribed form) Buteo [undescribed form]
Principe Scops-Owl (undescribed form) Otus [undescribed form]
San Isidro Owl (undescribed form) Ciccaba [undescribed form]
White-spotted Boobook (undescribed form) Ninox [undescribed form]
Inambari-Tambopata Antwren (undescribed form) Herpsilochmus [undescribed Inambari-Tambopata Antwren]
Loreto Antwren (undescribed form) Herpsilochmus [undescribed Loreto form]
Aripuana Antbird (undescribed form) Sciaphylax [undescribed form]
Lambayeque Tapaculo (undescribed form) Scytalopus [undescribed Lambayeque form]
Millpo Tapaculo (undescribed form) Scytalopus [undescribed Millpo form]
Ayacucho Tapaculo (undescribed form) Scytalopus [undescribed Ayacucho form]
Ampay Tapaculo (undescribed form) Scytalopus [undescribed Ampay form]
Yungas Woodcreeper (undescribed form) Deconychura [undescribed form]
Bahia Treehunter (undescribed form) Heliobletus [undescribed form]
Mantaro Thornbird (undescribed form) Phacellodomus [undescribed form]
Araguaia River Spinetail (undescribed form) Certhiaxis [undescribed form]
Necklaced Spinetail (undescribed form) Synallaxis stictothorax [undescribed La Libertad form]
Amazonian Spinetail (undescribed form) Synallaxis [undescribed Amazonian form]
Mantaro Spinetail (undescribed form) Synallaxis [undescribed Mantaro form]
White-tailed Tityra (unrecognized species) Tityra leucura [unrecognized species]
Maranhao-Piaui Pygmy-Tyrant (undescribed form) Myiornis [undescribed form]
Peruvian Tyrannulet (Amazonas) Zimmerius viridiflavus [undescribed form]
Orinoco Wagtail-Tyrant (undescribed form) Stigmatura [undescribed form]
Alor Myzomela (undescribed form) Myzomela [undescribed Alor form]
Taliabu Myzomela (undescribed form) Myzomela [undescribed Taliabu form]
Peleng Fantail (undescribed form) Rhipidura [undescribed form]
Bacan Drongo (undescribed form) Dicrurus [undescribed form]
Bismarck Flyrobin (undescribed form) Microeca [undescribed form]
Kilombero Cisticola (undescribed form) Cisticola [undescribed Kilombero form]
White-tailed Cisticola (undescribed form) Cisticola [undescribed White-tailed form]
Taliabu Grasshopper-Warbler (undescribed form) Locustella [undescribed form]
Taliabu Leaf Warbler (undescribed form) Phylloscopus [undescribed form 1]
Banggai Leaf Warbler (undescribed form) Phylloscopus [undescribed form 2]
Lesser Whitethroat (Lesser) Sylvia curruca curruca/blythi/halimodendri
Lesser Whitethroat (Lesser/Desert) Sylvia curruca curruca/minula
Lesser Whitethroat (Desert/Gansu) Sylvia curruca minula/margelanica
Lesser Whitethroat (Lesser/Hume’s) Sylvia curruca curruca /althaea
Lesser Whitethroat (Lesser/Desert/Hume’s) Sylvia curruca curruca/minula/althaea
Subalpine Warbler (cantillans/inornata) Sylvia cantillans cantillans/inornata
Meratus White-eye (undescribed form) Zosterops [undescribed Meratus form]
Wangi-Wangi White-eye (undescribed form) Zosterops [undescribed Wangi-Wangi form]
Obi White-eye (undescribed form) Zosterops [undescribed Obi form]
Mantaro Wren (undescribed form) Pheugopedius [undescribed form]
Meratus Jungle-Flycatcher (undescribed form) Cyornis [undescribed Meratus form]
Togian Jungle-Flycatcher (undescribed form) Cyornis [undescribed Togian form]
Spectacled Flowerpecker (undescribed form) Dicaeum [undescribed form]
Mount Mutis Parrotfinch (undescribed form) Erythrura [undescribed form]
Western Yellow Wagtail (lutea/flavissima) Motacilla flava lutea/flavissima
Western Yellow Wagtail (flava/beema) Motacilla flava flava/beema
Western Yellow Wagtail (iberiae/cinereocapilla/pygmaea) Motacilla flava [cinereocapilla Group]
Evening Grosbeak (type 1) Coccothraustes vespertinus (type 1)
Evening Grosbeak (type 2) Coccothraustes vespertinus (type 2)
Evening Grosbeak (type 3) Coccothraustes vespertinus (type 3)
Evening Grosbeak (type 4) Coccothraustes vespertinus (type 4)
Evening Grosbeak (Mexican or type 5) Coccothraustes vespertinus (type 5)
Red Crossbill (Wandering or type A) Loxia curvirostra (type A)
Red Crossbill (Bohemian or type B) Loxia curvirostra (type B)
Red Crossbill (Glip or type C) Loxia curvirostra (type C)
Red Crossbill (Phantom or type D) Loxia curvirostra (type D)
Red Crossbill (Parakeet or type E) Loxia curvirostra (type E)
Red Crossbill (Scarce or type F) Loxia curvirostra (type F)
Red Crossbill (Parakeet or type X) Loxia curvirostra (type X)
Red Crossbill (Appalachian or type 1) Loxia curvirostra (type 1)
Red Crossbill (Ponderosa Pine or type 2) Loxia curvirostra (type 2)
Red Crossbill (Western Hemlock or type 3) Loxia curvirostra (type 3)
Red Crossbill (Douglas-fir or type 4) Loxia curvirostra (type 4)
Red Crossbill (Lodgepole Pine or type 5) Loxia curvirostra (type 5)
Red Crossbill (Sierra Madre or type 6) Loxia curvirostra (type 6)
Red Crossbill (Enigmatic or type 7) Loxia curvirostra (type 7)
Red Crossbill (Newfoundland or type 8) Loxia curvirostra (type 8)
Red Crossbill (Sitka Spruce or type 10) Loxia curvirostra (type 10)
Pine Siskin (green morph) Spinus pinus (green morph)
Dark-eyed Junco (Slate-colored/cismontanus) Junco hyemalis hyemalis/carolinensis/cismontanus
White-crowned Sparrow (Dark-lored) Zonotrichia leucophrys leucophrys/oriantha
White-crowned Sparrow (Yellow-billed) Zonotrichia leucophrys nuttalli/pugetensis
Orange-crowned Warbler (Gray-headed) Leiothlypis celata celata/orestera
San Pedro Tanager (undescribed form) Thraupidae [undescribed form]
Ibera Seedeater (undescribed form) Sporophila [undescribed form]