Overview

Go directly to December 2023 spreadsheet downloads with range updates

Go directly to October 2023 Taxonomy Updates & Corrections

This is the 17th installment of updates following the publication, in 2007, of the 6th edition of The Clements Checklist of Birds of the World. Because the Clements Checklist has become tightly interwoven with eBird, the checklist now is referred to as the eBird/Clements Checklist. The entire checklist (including documentation of all revisions and new range updates from v2023b) is available as a downloadable spreadsheet (in Excel and .csv formats). The most current spreadsheet is version 2023b (released December 2023) and represents an update to the most recent year’s taxonomic revision from October 2023 (i.e., the eBird/Clements Checklist v2023 released on 27 October 2023).

The Clements Checklist v2023b is a mid-year update that affects only range statements. There are no changes to taxonomy, names, or sequence in v2023b; these will be published in our v2024, expected in late October 2024. We are providing this mid-year update to improve consistency and format, make a small number of corrections, and incorporate many updates to range statements. This is a work in progress, and we plan to continue updating range statements in v2024 and beyond.

Most of the Clements et al. v2023 range statements have been modified in v2023b in at least slight or non-substantive ways (such as spelling out of cardinal directions or changing the order in which islands are listed in accordance with convention), while others have changed in more important ways, typically by addition of more detail, corrected/updated spellings and place names, and updating based on new information. Only those range statement changes in v2023b that we consider substantive are annotated in the “text for website v2023b” column, but users who wish to see the full set of differences can readily compare the two versions by, for example, pasting the range column for v2023 next to that for v2023b.

The list of the major October 2023 Updates & Corrections (e.g., new species, splits, lumps, and name changes) remain as-is. As noted above, however, full documentation of all changes is incorporated into the spreadsheet itself; and eBird also has a very useful summary of the major changes.

The Clements et al. (2023) spreadsheet contains the following fields (data columns):

• Sort v2023: This is the sequence of species, groups, and subspecies in eBird/Clements v2023.
• Species code:  Internal taxon identifier, added to the Clements Checklist 2023 and eBird/Clements Checklist v2023 and relates to the Cornell Lab internal identifiers for each taxon. These are not necessarily stable with respect to taxonomic concepts between versions, but they usually are and serve as a good method for URLs in eBIrd and Macaulay Library. Note that this field has traditionally been provided for the eBird Taxonomy, but these codes are new for subspecies and families this year.
• Taxon Concept Id: A persistent, unique identifier for the taxonomic concept which is maintained by Avibase (https://avibase.bsc-eoc.org/) and can be looked up in the URLs of that website (e.g., https://avibase.bsc-eoc.org/species.jsp?avibaseid=30FEC6BE). This is the best database identifier to be used to compare taxa between this version and future versions of the taxonomies.   It also can be used to track any changes to the circumscribed range of any taxon and can be compared to see how taxonomic concepts move between species_code or scientific name.
• Clements v2023 change: Concise note indicating that a change from eBird/Clements Checklist v2022 occurred for that entry. Sometimes only a single change is made per entry; in other cases several changes are made.
• Text for website v2023: This is a fuller explanation of the change(s) from Clements Checklist v2022 for that entry.
• Category: This indicates whether the entry on that line is a species; a subspecies; a monotypic group (i.e., a group that is equivalent to a single subspecies); or a polytypic group (a group composed of two or more subspecies). The total number of subspecies recognized in the eBird/Clements Checklist is the sum of all entries listed as “subspecies” and as “group (monotypic)”.
• English name
• Scientific name
• Authority: The name(s) of the person, or group of people, who described a species or subspecies, followed by the year of publication of the description (first added in 2022). Authorities are in ( ) if originally described in a different genus than now used here.
• Name and authority: The full scientific name combined with the authority, in a single column (first added in 2022).
• Range
• Order
• Family
• Extinct: An entry (1) in this column means that the species or subspecies is extinct.
• Extinct year: The year the species or subspecies went extinct or an approximation of the last year in which it was reported; “xxxx” is used when the date of extinction is not readily accessible.
• Sort v2022: The sequence of species in eBird/Clements Checklist v2022.
• Page 6.0: The page number of the species in the last (sixth) print edition (2007).
  

Summary Statistics for eBird/Clements Checklist v2023

Species

This year’s update includes three species newly described to science, all three of which were initially found years ago. It can take a long time and a huge amount of effort to document and scientifically describe new species, as demonstrated by the stories behind the descriptions of the Principe Scops-Owl Otus bikegila of Príncipe Island, Gulf of Guinea, West Africa, the Wangi-Wangi White-eye Zosterops paruhbesar, from the island of Wangi-wangi southeast of Sulawesi, and Ibera Seedeater Sporophila iberae from northern Argentina and now being reported more widely.

Otherwise, this year’s checklist includes 124 splits and 16 lumps; including the three new species listed above, this amounts to a net gain of 111 species. In terms of splits and lumps, we are current with the 2023 decisions of the American Ornithological Society’s North American Classification and Nomenclature Committee (NACC), and the decisions of the South American Classification Committee (SACC) through July 2023. Additionally, the eBird/Clements Checklist is a participant in the Working Group Avian Checklists (WGAC), a collaborative effort at reaching consensus and alignment on avian classification, under the auspices of the International Ornithologists’ Union. Currently WGAC is focused on alignment at the level of the species and genus. In the future, after WGAC completes the first sweep across all species-related cases, consensus will be sought at higher and lower levels of classification and staying current with new research findings. We have implemented most WGAC decisions through June 2023.

Taxon Concept Identifiers

This year we include Taxon Concept ID as a separate column for the first time; this is a unique taxonomic identifier meant to identify a specific taxonomic concept. The same English name, scientific name, and even type specimen may be applied to different populations over time, even across versions within a single taxonomy. A Taxon Concept ID refers to a population with shared characteristics and a specific range circumscription and not to the treatment of these populations within a specific taxonomy. For example, when well-defined subspecies or subspecies groups are elevated to species level (i.e., a split), the Taxon Concept IDs for each of these will not change even though the common and scientific names and taxonomic rank will change. A change to the genus or the spelling of a scientific name will not result in a change to the Taxonomic Concept ID. Taxon Concept IDs are the best way to track taxonomic changes through time and to accurately integrate unrelated datasets. We use the Taxon Concept IDs developed and maintained by Avibase (https://avibase.bsc-eoc.org/) which also maintains linkages between avian taxonomic authorities and versions through time. Example: In 2021, eBird/Clements lumped Northwestern Crow (Corvus caurinus) with American Crow (Corvus brachyrhynchos), resulting in no name change for American Crow but a substantial change in the range of American Crow, since populations in coastal British Columbia and Alaska are now included in American Crow (Corvus brachrhynchos). Consequently, this lump results in 1) deletion of Northwestern Crow (Corvus caurinus) from the dataset; 2) conversion of all those former Northwestern Crow records to American Crow (Corvus brachyrhynchos); 3) change in the TAXON CONCEPT ID for American Crow (Corvus brachyrhynchos) from avibase-9E9F2476 to avibase-69544B59. Thus, the TAXON CONCEPT ID helps to track taxonomic changes, including those where the name might not change but the actual taxonomic concept does change, such as American Crow (Corvus brachyrhynchos).

Groups

eBird/Clements Checklist has adopted the concept of the group, which initially was developed by eBird. A “group” is a distinctive (field identifiable) subspecies or group of subspecies. The group is not a formal taxonomic unit, but often represents a potential future split (and so groups are a valuable taxonomic tool).

Higher-Level Taxonomy

Two additional families (Hylias, Hyliidae and Parrotbills, Paradoxornithidae) are recognized this year, and none are lost, so the total number of extant families in the eBird/Clements Checklist is 251 (including the family Hawaiian honeyeaters, Mohoidae of Hawaii, all species of which are extinct).

These 251 families are listed below, with the names of orders in the left column in bold, followed by the number of families in that order (in parentheses, after the name of each order). The middle and right columns are the scientific and English names of the families followed by the number of species in each family (in parentheses, after the name of each family).