chickennet-research-0.1.0-perch2

ChickenNet Research 0.1.0 — Perch 2

A research-only three-head chicken-vocalization classifier fitted on frozen 1,536-dimensional Google Perch 2 embeddings.

Status: frozen public research candidate; these exact joblib bytes are not deployed.

Artifact SHA-256: a5b83b648b19d2837fe775161cf35fce22f2a717e630c08253f2b9c6d2fe58d0

Dataset hash: 974df55df9a3262944e32563e1111cf6f32cf52a128548a39aab5d69852bc3b0

Current operational relationship

Since July 2026, a later JSON/NPZ successor from the ChickenNet research family has operated as a conservative review-only head in the private field site's shared Perch 2 listener. That successor is chickennet-dev2-field-probe, bundle ID d81cd5aee82176065f79abe4ae19db69f5c52c0ca4818d43fd981bf7781dcc41, with field review threshold 0.9999. Its exact checked bundle is now published as ChickenNet Research 0.2.0.

The successor is a distinct artifact; it is not this joblib under another name. Its threshold crossings remain unconfirmed model assertions. Deployment does not transfer field-validation claims to this frozen public candidate. See the living deployment contract.

Outputs

The fitted heads are independent. They are not a softmax and do not sum to one. The serialized inference contract gates both subtype heads on chicken_vocalization_present, so crow or other-vocalization labels are suppressed when the broad head does not pass.

A window may activate the broad presence head plus one subtype head. Low scores across every head should be treated as abstention/background.

Feature contract

• Backbone: Google Perch 2 CPU release
• Input to Perch: five seconds, 32 kHz, mono, float32
• Input to this artifact: one 1,536-dimensional Perch embedding
• Verified Perch model-tree SHA-256: 3fb2d54b3e34534f1130052b25737e54bbb5ebfd340ec040d4510772b64c81ff
• The Perch weights are not included in this repository.

The official Perch code repository is Apache-2.0. The Kaggle model-weight license was not exposed by the metadata available during this build, so this card does not claim that the weights themselves are Apache-2.0.

Training data

Total: 2,317 five-second windows.

Ross-308 was split by individual bird. Its health and lighting fields were retained only as provenance, never used as targets. Clean annotations were merged into non-overlapping five-second contexts from the parent recordings. Noisy/clipped/contact-artifact annotations were excluded and logged.

ESC-50 was split by original Freesound src_file, not its published fold alone. The audit found original source IDs crossing published folds; grouping by src_file prevents that leakage.

No source audio is redistributed here.

Evaluation

Internal grouped test

These values are an internal fit check, not field-readiness evidence. Crow support is especially small, and source-domain shortcuts can remain despite grouped splits.

Locked external iNaturalist challenge

The thresholds were frozen before this challenge. It contains 42 permissively licensed Domestic Chicken sounds from 30 observers: 31 CC BY and 11 CC0.

• Broad-head passes: 33/42
• Broad-head weak-positive hit rate: 78.6%
• Median broad-head score: 0.858

This is a taxon-level weak-positive challenge. A centered crop may not contain an audible chicken call. It has no negative examples, so precision and false-positive rate cannot be measured. Crow versus other-call metrics are not reported because call type is not annotated.

Private stationary-microphone confound audit

A private reviewed frog archive supplied 1,308 local fixed-microphone windows. Chicken absence was not separately reviewed, so the following is an upper bound on candidate false positives, not a confirmed false-positive rate:

• broad-head candidate positives: 10/1,308 windows across 8/436 files;
• crow-head candidate positives: 9/1,308 windows across 7/436 files;
• other-vocalization candidate positives: 0/1,308 windows.

No private paths or audio are included in the public artifact.

Use

import joblib
from chickennet.candidate import active_labels, predict_candidate

package = joblib.load("chickennet-research-0.1.0-perch2.joblib")
embedding = ...  # shape (N, 1536), produced by the verified Perch 2 feature contract
scores = predict_candidate(package, embedding)
detections = [active_labels(package, row) for row in scores]

Do not feed waveforms directly into this artifact.

Limitations

• Not calibrated for local field deployment.
• No independently reviewed chicken-negative field set yet.
• Crow has only four positive test examples.
• Domestic Chicken taxonomy does not provide call-type labels.
• Ross-308 is a small controlled broiler corpus.
• ESC-50 introduces a noncommercial restriction and coarse source domains.
• The private local candidate positives still require listening review.
• Thresholds should not be changed on the published external challenge.

Sources

• Ross-308: Díaz de Cerio et al., DOI 10.34810/DATA3437
• ESC-50: Piczak, DOI 10.1145/2733373.2806390
• Perch: Ghani et al., Global birdsong embeddings enable superior transfer learning for bioacoustic classification, Scientific Reports (2023)

Source summaries, retained-private manifest hashes, run metrics, and the public challenge report are included alongside the artifact. Exact row-level training manifests are not published; the public bundle supports artifact/summary consistency checks but cannot by itself reproduce every split assignment.

Git source

This historical Perch 2 artifact belongs to the ChickenNet repository; it is not part of the legacy BirdNET-logit InsectNet repository.