BIRD TAXONOMY / VERSIONED CLASSIFICATION DOSSIER v0.1

Status: RESEARCH / PRE-CAPTURE ONLY
Utility family: VERSIONED CLASSIFICATION + OBSERVATION REPROJECTION
Fixture: Warbling Vireo complex — Vireo gilvus / Vireo swainsoni
Authority comparison: eBird/Clements v2024 → AOS 66th Supplement / eBird-Clements v2025 → AviList v2025b / v2026 issue queue
Research date: 2026-08-09
Authority: NONE — research input only
Explicit non-claims: No CaptureReceipt, SourceEdition, taxonomic adjudication, species identification, SRS receipt, standing, or canonical Counterpedia identity is created here.

A. WHY THIS SUBJECT

The user question is gentle:

“What species is this bird?”

Most knowledge systems answer as though the species name were simply a property of the organism.

But biological classification is an institutional, versioned model over populations.

A bird does not mutate because a checklist changes.

A field observation does not gain new anatomical or acoustic evidence because a committee publishes a split.

And the same scientific-name string can change meaning because its circumscription changes.

This fixture demonstrates a new Counterpedia primitive:

CLASSIFICATION IS A VERSIONED PROJECTION OVER THE WORLD, NOT THE WORLD ITSELF.

B. THE FIXTURE

BIRD-POP1 — Warbling Vireo complex

Historically, North American checklists treated eastern and western Warbling Vireos as one species:

Warbling Vireo
Vireo gilvus

The western forms were subspecies within that broader species concept.

In 2025 the American Ornithological Society's North and Middle America committee split Vireo swainsoni from Vireo gilvus.

The resulting AOS treatment is:

Eastern Warbling-Vireo
Vireo gilvus

Western Warbling-Vireo
Vireo swainsoni

eBird/Clements v2025 adopted the same split.

AviList v2025b, published June 2026, did not make taxonomic changes from AviList v2025. AviList's 2026 issue queue lists the Warbling Vireo split as under consideration for the forthcoming v2026 checklist.

Therefore, in August 2026, one can legitimately encounter different current checklist states depending on the named authority/version.

The organism did not change.

The classification did.

C. THE MOST IMPORTANT IDENTITY PROBLEM

Before the split:

Vireo gilvus
=
broad Warbling Vireo concept
=
eastern + western populations

After the AOS split:

Vireo gilvus
=
Eastern Warbling-Vireo
=
narrower eastern concept

The string is the same.

The extension of the taxon is not.

Therefore Counterpedia must never use:

scientific_name_string == taxon_identity

as its identity rule.

This is the quiet-taxonomy equivalent of the museum object's accession lesson.

A taxon concept needs at least:

authority
checklist
version
scientific_name
circumscription
parent/split lineage

D. SOURCE INVENTORY

BIRD-S01 — AOS Sixty-sixth Supplement

Issuer: American Ornithological Society
Publication: Sixty-sixth supplement to the American Ornithological Society’s Check-list of North American Birds
Journal: Ornithology 142(3), 2025
Published: 14 August 2025
Locator: https://academic.oup.com/auk/article/142/3/ukaf015/8231021
Source class: primary taxonomic authority decision
Priority: P0

The supplement:

• adds Vireo swainsoni as a species split from Vireo gilvus;

• changes Vireo gilvus to Eastern Warbling-Vireo;

• creates Western Warbling-Vireo for Vireo swainsoni;

• cites concordant genetic, morphological, song, molt, migration and brood-parasitism differences;

• notes low levels of hybridization / cytonuclear discordance across a broad contact region.

This is the authority-changing artifact.

BIRD-S02 — eBird 2025 Taxonomy Update

Issuer: Cornell Lab of Ornithology / eBird
Title: 2025 eBird Taxonomy Update
Locator: https://science.ebird.org/en/use-ebird-data/the-ebird-taxonomy/2025-ebird-taxonomy-update
Source class: operational checklist / observation-remapping authority
Priority: P0

The 2025 eBird/Clements taxonomy incorporates the AOS split.

For Warbling Vireo, eBird states that:

• eastern and western birds are now separate species;

• breeding birds can often be safely assigned geographically and/or by song;

• many migrants, wintering birds and contact-zone records cannot be safely assigned;

• ambiguous records are retained as Eastern/Western Warbling Vireo;

• eBird treats slash taxa as an important data-integrity mechanism;

• bulk conversion rules vary by geography and season;

• British Columbia records are presumed Western under its published conversion logic;

• observer records should not be made more specific when evidence does not support that specificity.

This source is crucial because it demonstrates classification migration of a living observation database rather than merely a checklist publication.

BIRD-S03 — AviList v2025b

Issuer: AviList Core Team
Title: The Checklist v2025b
Published: 11 June 2026
Locator: https://www.avilist.org/checklist/v2025b/
Source class: global consensus checklist edition
Priority: P0

AviList states:

• v2025b is a minor revision of v2025;

• core taxonomic fields such as English and scientific names were not changed;

• taxonomic/nomenclatural changes are reserved for v2026;

• the checklist is explicitly versioned and previous editions remain available.

For this dossier, exact row bytes for the Vireo gilvus concept should be captured in CAP1 before formal source-resolution/adjudication.

The current state is inferred from BIRD-S03 together with BIRD-S04 below: v2025b did not adopt the 2025 AOS split, while the split is explicitly queued for AviList v2026 consideration.

BIRD-S04 — AviList Issues Under Consideration

Issuer: AviList
Title: Issues under Consideration
Observed update: July 2026
Locator: https://www.avilist.org/checklist/issues-under-consideration/
Source class: prospective taxonomy-governance record
Priority: P0

The page lists:

split
Vireo gilvus
split Vireo swainsoni from V. gilvus (Warbling Vireo)

and references the AOS-NACC 2025 proposal / 66th Supplement.

AviList says:

• issues in this table are under review for the next version;

• decisions are not final until published;

• v2026 is planned for September or October 2026.

This gives Counterpedia an unusual lifecycle state:

AOS/eBird:
  ADOPTED

AviList v2025b:
  NOT YET ADOPTED

AviList v2026:
  UNDER CONSIDERATION

The pending proposal is not a future fact.

BIRD-S05 — Carpenter et al. cryptic-speciation study

Authors: Amanda M. Carpenter et al.
Title: Genetic, bioacoustic and morphological analyses reveal cryptic speciation in the warbling vireo complex (Vireo gilvus: Vireonidae: Passeriformes)
Journal: Zoological Journal of the Linnean Society 195(1):45–64
DOI: 10.1093/zoolinnean/zlab036
Locator: https://academic.oup.com/zoolinnean/article/195/1/45/6407100
Source class: peer-reviewed primary scientific evidence
Priority: P0

The study found:

• two major eastern/western mitochondrial groups;

• additional structure in nuclear markers;

• acoustic, ecological and morphological differentiation;

• support for long-standing eastern/western divergence;

• recommendation that eastern and western Warbling Vireos may be best treated as separate species;

• caution that further work in contact zones was warranted before formal taxonomic revision.

This distinction matters:

scientific evidence supports split
≠
authority has adopted split

A research paper can supply evidence to an authority decision without itself becoming the checklist.

BIRD-S06 — Carpenter et al. contact-zone / hybridization study

Title: Do habitat and elevation promote hybridization during secondary contact between three genetically distinct groups of warbling vireo (Vireo gilvus)?
Journal: Heredity 128:352–363
Published: 2022
DOI: 10.1038/s41437-022-00529-x
Locator: https://www.nature.com/articles/s41437-022-00529-x
Source class: peer-reviewed primary scientific evidence
Priority: P1

This work informs the contact-zone problem and helps explain why classification and field identification are related but not identical problems.

E. SYNTHETIC OBSERVATION FIXTURE 1 — CLEAR WESTERN RECORD

This is a synthetic demo observation, not a claim that Counterpedia captured an actual bird.

Observation WV-OBS-01

observed_at:
  2024 breeding season

location:
  British Columbia, Canada

observer_label_at_time:
  Warbling Vireo

evidence:
  location
  date
  optional song recording

taxonomy_at_observation:
  eBird/Clements v2024

At observation time:

Warbling Vireo
Vireo gilvus

is a perfectly ordinary species-level label under the then-current eBird/Clements treatment.

After eBird/Clements v2025 adopts the split, eBird's published record-migration logic presumes British Columbia records to be Western unless evidence indicates otherwise.

The projected current eBird classification becomes:

Western Warbling Vireo
Vireo swainsoni

But under the still-unsplit AviList v2025b concept, the corresponding taxonomic projection remains the broad Warbling Vireo concept pending AviList's next taxonomic release.

Therefore one immutable observation can have multiple classification projections:

WV-OBS-01
   │
   ├── eBird/Clements v2024
   │      Warbling Vireo
   │      Vireo gilvus [broad concept]
   │
   ├── eBird/Clements v2025
   │      Western Warbling Vireo
   │      Vireo swainsoni
   │
   └── AviList v2025b
          Warbling Vireo concept
          split not yet adopted

The field observation is not rewritten.

F. SYNTHETIC OBSERVATION FIXTURE 2 — AMBIGUOUS MIGRANT

Now use a second synthetic record:

Observation WV-OBS-02

observed_at:
  migration season

location:
  region where both eastern/western birds may occur

evidence:
  visual observation only
  no diagnostic song
  no genetics
  no decisive morphology

Under the older one-species taxonomy:

Warbling Vireo
Vireo gilvus

was species-level identification.

After the split, the observation evidence may support only:

Eastern/Western Warbling Vireo
Vireo gilvus/swainsoni

This is an extraordinary knowledge-system regression test:

A taxonomy can become more precise while a historical observation becomes less taxonomically specific.

Nothing has gone wrong.

The new classification asks a question the old observation was never required to answer.

G. DO NOT RETROACTIVELY INVENT EVIDENCE

Counterpedia must never do:

2024 observer:
  Warbling Vireo

2025 split:
  western map cell

system:
  "observer identified Western Warbling Vireo"

unless the system clearly marks that as a later deterministic reprojection under a named taxonomy and conversion rule.

The historical observation remains:

observed_label:
  Warbling Vireo

The later projection can be:

projected_taxon:
  Western Warbling Vireo

projection_basis:
  eBird/Clements v2025
  geographic conversion rule

These are different facts.

H. TAXON CONCEPT, NOT NAME STRING

Counterpedia needs a graph like:

TaxonConcept
  authority
  checklist_version
  rank
  scientific_name
  English_name
  circumscription
  included_lower_taxa
  geographic concept
  source_edition

Then:

TaxonConcept EBIRD-2024-WARVIR
  scientific_name = Vireo gilvus
  circumscription = eastern + western Warbling Vireo complex

versus:

TaxonConcept AOS-2025-EASTERN
  scientific_name = Vireo gilvus
  circumscription = eastern lineage only

The identical binomial is not enough to merge these nodes.

I. SPLIT LINEAGE

The taxonomic relationship is concept lineage:

Warbling Vireo
Vireo gilvus sensu broad pre-2025
        │
        ├── retained narrower concept
        │      Eastern Warbling-Vireo
        │      Vireo gilvus
        │
        └── split child
               Western Warbling-Vireo
               Vireo swainsoni

A split is not:

old species was false

It is:

authority now partitions the former concept differently

J. AUTHORITY IS PART OF THE ANSWER

Ask on 2026-08-09:

“What species is the western Warbling Vireo population?”

Counterpedia should not emit one naked answer.

It should be able to return:

AOS-NACC 2025:
  Western Warbling-Vireo
  Vireo swainsoni

eBird/Clements v2025:
  Western Warbling Vireo
  Vireo swainsoni

AviList v2025b:
  split not yet incorporated
  current concept remains broader pending v2026 review

AviList v2026:
  NOT PUBLISHED

That is not indecision.

That is accurate authority scoping.

K. PENDING ≠ ADOPTED

AviList's issue queue is ideal for Counterpedia lifecycle semantics.

proposal:
  split Vireo swainsoni from V. gilvus

state:
  under consideration

future edition:
  v2026 planned

current edition:
  v2025b

The system must refuse:

“AviList has split Warbling Vireo.”

until the published edition actually does so.

Likewise:

“AviList will split it.”

is too strong while the proposal is merely under consideration.

This gives us:

PROPOSED
UNDER_REVIEW
ADOPTED
PUBLISHED
SUPERSEDED

as distinct lifecycle states.

L. EVIDENCE ≠ TAXONOMIC AUTHORITY

The Carpenter paper supports eastern/western divergence.

But it is not interchangeable with:

• AOS committee decision;

• eBird operational taxonomy;

• AviList consensus checklist.

Counterpedia should model:

scientific_study
  supports
taxonomic_proposal

taxonomic_authority
  evaluates
proposal

checklist_edition
  publishes
taxon_concept

No direct jump from:

paper says divergence

to:

therefore species

without naming the species concept / authority context.

M. CLASSIFICATION AND IDENTIFICATION ARE DIFFERENT

A taxonomic split answers:

How should populations be classified?

A field identification asks:

Which classified population did this individual observation belong to?

The first can become more resolved while the second remains ambiguous.

eBird's slash treatment demonstrates exactly this.

Therefore:

taxonomy_resolution
≠
observation_resolution

N. 30-SECOND DEMO

Show one old bird checklist:

JUNE 2024
British Columbia

Warbling Vireo
Vireo gilvus

Move taxonomy slider:

eBird/Clements 2024

WARBLING VIREO
Vireo gilvus

eBird/Clements 2025

WESTERN WARBLING VIREO
Vireo swainsoni

Why did this change?
AOS 66th Supplement split western population.
Record mapped under eBird's published geographic rule.

Now switch authority:

AviList v2025b

WARBLING VIREO
broader taxon concept

status:
AOS split is under consideration for AviList v2026

Same bird.

Same observation.

Different governed classification projection.

That's the reveal.

O. SECOND 30-SECOND DEMO — PRECISION CAN GO DOWN

Show an older migrant observation:

2024
Warbling Vireo
species-level

Apply the new taxonomy.

Instead of confidently selecting East or West:

Eastern/Western Warbling Vireo

Counterpedia says:

The taxonomy got more precise. The old observation did not.

This may be the best sentence in the entire Quiet Utility corpus.

P. REVERSE-WIKIPEDIA VALUE

Open the AOS 66th Supplement:

AOS split decision
      ↓
new taxon concept:
Western Warbling-Vireo
      ↓
eBird/Clements adoption
      ↓
record-migration rules
      ↓
millions of potential historical observation projections

Open the Carpenter study:

genetics + song + morphology
      ↓
evidence used in taxonomic reasoning
      ↓
AOS decision
      ↓
downstream checklist editions

Open the AviList issue page:

AOS decision
      ↓
AviList proposal under consideration
      ↓
NOT YET current AviList taxonomy

One paper / one committee decision can have a massive reverse dependency graph.

Q. FIVE QUIET-UTILITY CLAIM ROLES

Candidate vocabulary only.

BIRD-Q1 — TAXON CONCEPT

Vireo gilvus under the pre-2025 broad Warbling Vireo treatment is not the same circumscription as Vireo gilvus under the AOS 2025 Eastern Warbling-Vireo treatment.

BIRD-Q2 — AUTHORITY-SCOPED CLASSIFICATION

AOS-NACC and eBird/Clements v2025 recognize Western Warbling Vireo Vireo swainsoni as a species.

BIRD-Q3 — PENDING CLASSIFICATION

As of the current AviList v2025b cycle, the same split is under consideration for AviList v2026 rather than silently treated as already published.

BIRD-Q4 — OBSERVATION REPROJECTION

A historical Warbling Vireo record can be deterministically projected to a newer taxon under a named checklist conversion rule without altering the observation's original label.

BIRD-Q5 — RESOLUTION LOSS

An observation once valid at species level under a broad concept may support only a slash / unresolved species pair after that concept is split.

R. WHY-NOT SPECIMENS

Why not 1

“Scientists discovered that Warbling Vireo never existed.”

Refuse.

The former broad taxon concept was a valid classification used by named authorities. The later split repartitions that concept.

Why not 2

“My 2024 sighting changed species in 2025.”

Qualify.

The bird and observation did not change. A later taxonomy may reproject the observation into a different taxon concept.

Why not 3

“The Latin name stayed Vireo gilvus, so nothing changed.”

Refuse.

The circumscription of Vireo gilvus narrowed under the split.

Why not 4

“AviList's issue page says the split, so AviList already recognizes it.”

Refuse.

An issue under consideration is not a published checklist decision.

Why not 5

“If eBird can't decide East or West after the split, the old observation was bad.”

Refuse.

The original observation may have been fully adequate for the taxonomy then in force. The new taxonomy asks for finer evidence.

S. PRODUCT PRIMITIVES THIS FIXTURE REQUIRES

1. Taxon-concept identity

Never scientific-name string alone.

2. Named taxonomy authority + exact edition

AOS-NACC / 66th Supplement
eBird/Clements / v2025
AviList / v2025b

3. Split/lump lineage

split_from
retains_name_from
narrows_circumscription_of
lumped_into

4. Observation identity independent of classification

The immutable observation survives taxonomy migrations.

5. Classification projection

observation
  ×
taxonomy edition
  ×
conversion evidence/rule
=
classification projection

6. Unresolved/slash concepts

Ambiguity is a governed output, not a data-quality embarrassment.

7. Proposal lifecycle

Proposal / vote / adopted / published must remain distinct.

T. CAPTURE PRIORITY — BIRD CAP1

P0

1. BIRD-S01 AOS 66th Supplement exact article/PDF bytes

2. BIRD-S02 eBird 2025 taxonomy-update page

3. BIRD-S03 AviList v2025b short or extended XLSX exact bytes

4. BIRD-S04 AviList current issues-under-consideration page

5. BIRD-S05 Carpenter et al. peer-reviewed article / publisher artifact

P1

1. BIRD-S06 contact-zone / hybridization study

2. exact AOS 2025-C-3 proposal and committee votes/comments

3. eBird/Clements v2024 checklist bytes

4. eBird/Clements v2025 checklist bytes

5. AviList v2025 decision-summary row for Vireo gilvus

6. current IOC row(s) for comparison, if useful

P2

1. one historical Warbling Vireo observation fixture with photo/audio and permission for demo use

2. one ambiguous migration observation fixture

3. museum specimen metadata linking old/new taxon concepts

U. CAPTURE / INGEST / CLASSIFICATION DISCIPLINE

checklist editions
committee supplement
primary research papers
observation artifacts
        ↓
CAP1-A exact custody
        ↓
CAP1-B dagr-ingest
        ↓
SRC1 edition identity
        ↓
taxon-concept extraction
        ↓
authority-scoped adjudication
        ↓
observation classification projection
        ↓
reader taxonomy/time/authority switcher

CAP1 does not identify birds.

Ingest does not choose a taxonomy.

A research paper does not publish a checklist.

A pending proposal does not become current classification.

V. REGRESSION TESTS LEARNED FROM THIS FIXTURE

BIRD-R1 — Same scientific name can mean a different taxon concept

Vireo gilvus broad pre-split ≠ Vireo gilvus narrow post-split.

BIRD-R2 — Observation identity survives taxonomic change

Do not rewrite what the observer recorded.

BIRD-R3 — Reprojection must name taxonomy + version + rule

No silent migration.

BIRD-R4 — More precise taxonomy can reduce observation specificity

Species-level old record may become a slash.

BIRD-R5 — Authority disagreement is not corruption

Different current checklists may temporarily carry different treatments.

BIRD-R6 — Pending is not adopted

Proposal lifecycle must be explicit.

BIRD-R7 — Scientific evidence does not itself create authority

Paper → evidence; checklist authority → published classification.

BIRD-R8 — Split lineage must preserve the old concept

Historical pages/observations need the concept that actually existed then.

W. PROVISIONAL THESIS

This Quiet Utility entry establishes:

Counterpedia can tell you what a living thing is called without pretending that classifications are timeless properties of nature.

Its strongest public sentence is:

The taxonomy got more precise. The old observation did not.

Its deeper architecture sentence is:

A taxonomic name is meaningful only together with its authority, edition, circumscription, and lineage; observations must survive independently so they can be reprojected without rewriting history.

And its quiet-corpus invariant is:

When classifications change, preserve the observation and version the interpretation.