AviList Terms of Reference

Brown Booby Sula leucogaster plotus by Yann Muzika; Cornell Lab of Ornithology | Macaulay Library

Download the 12 Jun 2026 version of the AviList Terms of Reference (PDF)

1. Background

For many years, multiple global taxonomic bird lists were maintained by experts from different organisations. Recognising that maintaining multiple lists duplicates effort and causes taxonomic confusion among list users, AviList was developed over the period 2017-2024 as a collaboration between the International Ornithological Community (IOC) World Bird List, the eBird/Clements Checklist, Avibase, the North American Checklist Committee (NACC), the South American Checklist Committee (SACC) and BirdLife International. The group maintains a strong association with the International Ornithologists’ Union (IOU). These terms of reference describe the processes AviList follows for maintaining the global list.

2. Vision

A unified checklist of the world’s bird species and subspecies that becomes the primary global point of reference on avian taxonomy.

3. Mission

To generate, promote and curate the most up-to-date, comprehensive and widely adopted open-access data source on the taxonomy, classification and nomenclature of the world’s extant and recently extinct bird species, based on the Biological Species Concept and an integrative taxonomic approach.

4. Objectives

  • To provide information on the taxonomy, classification, authorship, date, original descriptions, bibliographic references and type information for described taxa that can be linked to distributional data, IUCN Red List assessments and other pertinent information.
  • To become the preferred taxonomic source for regional, national and international organizations and bodies working in government, law enforcement, trade, conservation, science and the broader ornithological community.
  • To undertake and promote an open and transparently documented taxonomic decision-making process on the basis of which decisions can be seen by the global ornithological community to be consistent, dependable and fair.
  • To create a mechanism to allow the wider ornithological community to propose taxonomic changes and to provide input on decisions.
  • To assist the ornithological community by converging on consensus positions in difficult taxonomic cases.
  • To promote the science of taxonomy globally by highlighting areas where further research is most needed.
  • To ensure AviList incorporates input from the wider ornithological community through the inclusion of socially and geographically diverse voices and communities at all levels. 
  • To ensure that the objectives of AviList are being met through a rigorous process of monitoring and evaluation.

5. Standards and Principles

  • Generally accepted principles of academic freedom are applicable to all intellectual activities undertaken by, or under the direction of, participants in this process.
  • All participants acknowledge that the success of AviList requires a co-operative working relationship established upon a foundation of mutual trust, good communication and substantive commitments from all concerned.
  • All participants respect and abide by the independent scientific process for assessing taxonomic limits, and positively promote and communicate AviList and the messages emerging from it.
  • All taxonomic assessments, to the extent that this is reasonably possible within available resources, are correctly and adequately documented and supported by the best scientific information available.
  • All taxonomic decisions are open to external challenge.
  • AviList exists as an annually updated electronic file available publicly on a dedicated website (avilist.org).
  • Joint fundraising for activities in support of the development of AviList is encouraged.
  • AviList is only available through the regular updates of the AviList website. Draft versions of AviList updates will not be available prior to publication on the AviList website.
  • AviList is not a prescriptive classification; the advancement of new hypotheses in the service of taxonomic progress should never be mistaken for non-compliance with AviList or any other checklist.
  • All Committees and Advisory Groups endeavour, as far as practically possible, to reflect diversity among their members, including in relation to gender, regional representation, age and other characteristics.
  • The recommended citation for AviList gives AviList Core Team as the authoring body [example: AviList Core Team (2025) AviList: The Global Avian Checklist v2025. avilist.org]. AviList Core Team refers to the four contributing committees (Executive, Taxonomic, Bibliographic and Nomenclatural, and Technical). Members of the AviList Core Team are listed within the checklist document to give appropriate recognition of their contributions.

6. Intellectual Property (IP)

  • AviList will be open access under a Creative Commons Licence.
  • Contributors will retain the IP on their contributions and, provided they do not compete with AviList, can apply their IP to other projects.
  • Each participant conserves the ownership of the IP they create if they are doing this on their own, or jointly if done as part of a group.
  • Each participant agrees, to the extent permitted by applicable law, to grant an irrevocable, nonexclusive, non-transferable, royalty-free license to use their Intellectual Property Rights in the data contributed to AviList.
  • All current and past committee members and contributors are detailed on the AviList website.
  • Regional and Specialist Advisory Groups are detailed on the AviList website.

7. Committee Structure

AviList is governed and/or advised by the following Committees and Advisory Groups:

  • Executive Committee
  • Taxonomic Committee
  • Bibliographic Committee
  • Nomenclatural Committee
  • Technical Committee
  • English Names Committee
  • Regional and Specialist Advisory Groups

7.1 Executive Committee

The Executive Committee is responsible for the strategic direction of AviList and ensuring that the Vision, Mission and Terms of Reference are adhered to and that the Objectives and Standards and Principles are being met. It comprises 8 to 10 members: a Chair, the Chairs of the Taxonomic, Bibliographic, Nomenclatural, Technical, and English Names Committees, and representatives of the Cornell Lab of Ornithology, BirdLife International, Avibase and the IOU (to be selected by those organisations). Any of the last four representatives may be Chairs of one of the Committees, or these may be different individuals. Other members of the five additional AviList committees can also be part of the Executive and will be chosen based on expertise and representational needs in the Executive. The Chair is a taxonomist who is independent of these committees and organisations (though may formerly have represented or worked for them) and is appointed by majority vote of the other members of the Executive Committee for a period of 5 years (provided they remain active), which can be renewed on expiry. The Chair can be removed before the expiry of this period by a majority vote of other Executive Committee members. A Deputy Chair is appointed from among other Executive Committee members by majority vote to conduct business in the Chair’s absence. The Committee shall meet as often as required, but at least once a year. The discussions may be conducted in person, by written communications, by email exchanges or by video conference. The Agenda and Minutes for all meetings will be prepared and circulated by the Chair. The final decisions of the Committee will be based on consensus as far as possible, or, if not, by a simple majority vote of all members (in the case of a tie, the Chair’s vote is decisive).

The duties of the Executive Committee include, but are not necessarily restricted to, the following:

  1. acting as the ultimate governance body for AviList
  2. guiding and supporting the development of AviList and monitoring its application, uptake and impact
  3. agreeing on realistic priorities, within available resources, relating to curating, updating and expanding AviList, and the processes and information systems that support it
  4. identifying additional resources required to support AviList and working towards securing them
  5. considering and establishing mechanisms for incentivizing and mobilizing support for AviList and identifying areas of possible collaboration with taxonomists and end-users globally
  6. appointing the Chairs of the other Committees
  7. helping resolve disputes or disagreements within or between other Committees
  8. reviewing and deciding on revisions to the Terms of Reference set out in this document as required
  9. ensuring there is compliance with the process for monitoring adherence to the Mission, Objectives and Standards, and Principles set out in these Terms of Reference

7.2 Taxonomic Committee

The Taxonomic Committee comprises individuals with a range of relevant skills and appropriate experience required to assess species and subspecies limits under the Biological Species Concept using an integrative taxonomic framework as well as higher order classification. It comprises: (1) a Chair (appointed by the Executive Committee), (2) one representative each of the IOC checklist, the eBird/Clements checklist (produced by the Cornell Lab of Ornithology) and the BirdLife International checklist, nominated by those authorities, and (3) 4 to 8 other taxonomic experts, appointed by the Taxonomic Committee Chair with the agreement of the Executive Committee for a period of 5 years (provided they remain active), which can be renewed on expiry. Appointees can be re-appointed at the end of their tenure for subsequent terms. The Chair of the Taxonomic Committee is appointed by the Executive Committee for a period of 5 years, which can be renewed on expiry. It is intended that the Committee comprises no fewer than 6 and no more than 12 members, including the Chair. Members are selected for their proven scientific and technical competence in taxonomy and shall act in their personal capacity rather than as representatives of any organization. All decisions are based on rigorous assessments of all available data. Decisions are based on voting with a simple majority rule (one vote per member, including the Chair). In the case of a tie, members will be asked to revisit their votes in light of subsequent voting. If a tie still results then the Chair’s vote is decisive.

All decision-making discussion will be captured, documented and permanently stored; these discussions will be shared on the AviList website after publication of each annual revision.

The duties of the Taxonomic Committee include, but are not necessarily restricted to, the following:

  1. curating and annually updating the taxonomic treatments in AviList based on all available scientific data, including peer-reviewed journal publications, field guides, monographs, publicly accessible sound recordings, images, videos, unpublished reports, and personal observations. Specifically this includes:
    1. evaluating and resolving (by vote) discrepancies between AviList and other national, regional or global taxonomic lists
    2. evaluating newly published scientific literature relevant to assessing taxonomic limits and deciding (by vote) whether a change to AviList is warranted
    3. evaluating descriptions of newly described taxa and assessing (by vote) whether they warrant changes to AviList
    4. evaluating proposals for novel taxonomic changes, and appeals against previous changes, received from the wider ornithological community
  2. providing justifications for the taxonomic treatments followed
  3. providing scientific and technical recommendations, guidance and progress reports to other Committees, including the Executive Committee, as required
  4. establishing and overseeing the work of Regional and Specialist Advisory Groups to work on specific issues as necessary
  5. managing with the Technical Committee the mechanism by which the wider ornithological community provides relevant information and comment on decisions

7.3 Bibliographic Committee

Members of the Bibliographic Committee are selected on the basis of their specialized knowledge and familiarity with the primary literature that is relevant to the introduction and application of the scientific names applied to taxa in ornithology. Additionally, they have access to, and an understanding of, the secondary literature that addresses problematic cases. The Chair is appointed by the Executive Committee. Members are appointed by the Bibliographic Committee Chair with the agreement of the Executive Committee, initially for a period of 5 years (provided they remain active) and can be re-appointed at the end of their tenure for subsequent terms. It is intended that the Committee comprises no fewer than 6 and no more than 12 members, including the Chair. Decisions are based on discussions and general agreement between committee members.

The duties of the Bibliographic Committee include, but are not necessarily restricted to, the following:

  1. curating and annually updating bibliographic information in AviList based on all available scientific data, including peer-reviewed journal publications, monographs, the historic literature and exchanges among experts
  2. evaluating and resolving (by vote) bibliographic discrepancies between AviList and other national, regional or global taxonomic lists
  3. providing justifications for the bibliographic treatments followed

7.4 Nomenclatural Commitee

Members of the Nomenclatural Committee are selected on the basis of their general knowledge of avian nomenclature. The Chair is appointed by the Executive Committee. Members are appointed by the Nomenclatural Committee Chair with the agreement of the Executive Committee, initially for a period of 5 years (provided they remain active) and can be re-appointed at the end of their tenure for subsequent terms. It is intended that the Committee comprises no fewer than 6 and no more than 12 members, including the Chair. Decisions are based on voting with a simple majority rule (one vote per member, including the Chair). In the case of a tie, members will be asked to revisit their votes in light of subsequent voting. If a tie still results then the Chair’s vote is decisive.

The duties of the Nomenclatural Committee include, but are not necessarily restricted to, the following:

  1. curating and annually updating nomenclatural information in AviList based on all available scientific data, including peer-reviewed journal publications, monographs, the historic literature and exchanges among nomenclatural experts
  2. evaluating and resolving (by vote) nomenclatural discrepancies between AviList and other national, regional or global taxonomic lists
  3. providing justifications for the nomenclatural treatments followed

7.5 Technical Committee

Members of this Committee have specialist knowledge in data science and technology, particularly as it pertains to taxonomic databases and the development of software for managing and distributing taxonomic data. The Chair is appointed by the Executive Committee. Members of the Technical Committee will comprise representatives of the Cornell Lab of Ornithology and Avibase, and chosen by those organisations. Additional members can be appointed by the Technical Committee Chair with the agreement of the Executive Committee. Membership in the Technical Committee is for a period of 5 years (provided members remain active); members can be re-appointed at the end of their tenure for subsequent terms. It is intended that the Committee comprises no fewer than 3 and no more than 6 members, including the Chair.

The duties of the Technical Committee include, but are not necessarily restricted to, the following:

  1. managing AviList content
  2. identifying potential incongruencies in the data
  3. building and managing software to allow the committees to submit and review cases
  4. building and managing software and online platforms to allow the wider ornithological community to contribute to the AviList process, e.g. by submitting proposals and appeals or contributing relevant information to ongoing issues
  5. generating AviList outputs for public distribution

7.6 English Names Committee

For v2025 published on 11th June 2025, AviList adopted the English names of bird species published within the IOC World Bird List (v15.1) as its default (except where taxonomy did not align). For v2026 and all subsequent versions, an English Names Committee (ENC) has been established. It comprises: (1) an independent Chair (appointed by the Executive Committee), (2) one representative each of the former IOC checklist, the former eBird/Clements checklist (produced by the Cornell Lab of Ornithology), and the former BirdLife International checklist, each nominated by those authorities, (3) the Chair of the Taxonomic Committee (TaxCom), and (4) additional representatives for the regions covered by AviList’s four Old World Regional Advisory Groups (RAGs), as needed. Members are appointed for a period of 5 years (provided they remain active). Appointees can be re-appointed at the end of their tenure for subsequent terms. The Chair of the English Names Committee is appointed for a period of 5 years, which can be renewed on expiry. It is intended that the Committee comprises no fewer than 7 and no more than 11 members, including the Chair. Decisions are based on voting with a simple majority rule (one vote per member, including the Chair). In the case of a tie, members will be asked to revisit their votes in light of subsequent voting. If a tie still results then the Chair’s vote is decisive.

While the English name choice of the ENC is the recommended name as a global standard, we acknowledge that regional preferences may exist in English names. Although we view global standardization and alignment of English names as desirable, where this cannot be achieved, we recommend that departures from AviList names follow official regional standards where available and remain as limited and aligned as possible. AviList collaborates with eBird and the Cornell Lab to support alternate English names, as well as common names in other languages, in the context of its global taxonomy.

The duties of the English Names Committee include, but are not necessarily restricted to, the following:

  1. liaise with Regional and Specialist Advisory Groups as required when proposing English name changes
  2. consider English name changes when necessitated through taxonomic change
  3. consider English name changes when necessitated through compelling social or cultural developments

7.7 Regional and Specialist Advisory Groups

Regional and Specialist Advisory Groups comprise existing regional and specialist taxonomic groups and new ones established by the Executive Committee or the Taxonomic Committee to help support the maintenance and development of AviList. The Regional and Specialist Advisory Groups will input regional and specialist perspectives on taxonomy, subspecies and distributions, and where relevant, on nomenclature and English names, for consideration by the relevant Committees. In the case of those Regional and Specialist Advisory Groups assisting the Taxonomic Committee, the Groups will submit taxonomic proposals and recommendations for the Taxonomic Committee to consider and decide upon, and may also assess submissions from the broader ornithological community for tabling to the Taxonomic Committee. Chairs of the Regional Advisory Groups may be invited to sit on the Taxonomic Committee with an observer status for set periods in order to build expertise across regions and avian taxonomic groups. However, to preclude conflicts of interest in the taxonomic decision process, members (including Chairs) of Regional Advisory Groups established by the AviList Executive cannot serve on AviList Committees. The Regional and Specialist Advisory Groups will be able to develop their own Terms of Reference and working practices provided they contribute to and are consistent with the Vision, Mission, Objectives and Principles of AviList.

The Chairs of the Regional and Specialist Advisory Groups are appointed by the Taxonomic  Committee and then endorsed by the Executive Committee. Advisory Group members are then appointed by the Chairs with the agreement of the Chair of the Taxonomic Committee. All members are appointed for a period of 5 years (provided they remain active) and can be re-appointed at the end of their tenure for subsequent terms.

The duties of the Regional and Specialist Advisory Groups may include, but are not necessarily restricted to, the following:

  1. responding to requests for information and advice from the Taxonomic Committee
  2. submitting high-quality taxonomic proposals for consideration by the Taxonomic Committee and thereby advancing taxonomic decision-making for their respective regions or areas of expertise
  3. taking under consideration serious taxonomic proposals from members of the public of their respective geographic region, and crafting them into compelling proposals for consideration by the Taxonomic Committee
  4. promoting AviList in their respective regions
  5. assisting the Taxonomic Committee in assessing subspecies limits
  6. providing recommendations for English name changes based on regional taxonomic changes or compelling social or cultural developments

Final decisions on taxonomic issues rest with the Taxonomic Committee, nomenclatural issues with the Nomenclatural Committee, and English names with the English Names Committee.