tphakala/Perch-v2-Models

Perch v2 Models (full + regional catalog)

Google's Perch v2 bioacoustic classifier in three deployment variants, plus a catalog of region-specific slices that are smaller and faster while staying numerically identical (bit-exact) to the full model on the species they keep.

Origin and attribution

• Perch v2 by Google Research (bird-vocalization-classifier): EfficientNet-B3, ~12M embedding + ~91M classification params, ~15,000 species.
• ONNX conversion and the DFT-to-MatMul (no_dft) optimization by justinchuby.
• Labels from cgeorgiaw/Perch (iNaturalist taxonomy).
• Regional slicing uses the BirdNET Geomodel v3.0 range filter (birdnet-team/geomodel) to pick each region's species.

Variants and hardware

filename token	precision	best for
_fp32	FP32, with DFT	GPU (CUDA/TensorRT), Intel CPU
_no_dft_fp32	FP32, DFT removed	ONNX Runtime on any CPU (recommended); CUDA and OpenVINO GPU. OpenVINO CPU only at f32
_int8_arm	partial INT8 (MatMul-only)	withdrawn 2026-11-15, kept for existing installs only, see Withdrawn files

Full model

file	MB
full/perch_v2_fp32.onnx	409
full/perch_v2_no_dft_fp32.onnx	413
full/perch_v2_int8_arm.onnx	131 (withdrawn)
full/perch_v2_labels.txt	14,795 classes

Why regional models

These slices are built for real-time detection on resource-constrained devices, phones, Raspberry Pi and other single-board computers, where running the full 14,795-class Perch v2 continuously is costly in both RAM and CPU. Most of that cost goes to recognising species that cannot occur at the listener's location. Restricting the model to a region's species shrinks the memory footprint and the per-inference compute (the classifier head is ~88% of the model), so an always-on detector keeps up with the live audio stream and leaves headroom for the rest of the application, on hardware where the full model would struggle. Each tile stays bit-exact to the full model on the species it keeps; the only change is that out-of-region species are not emitted, which at a fixed monitoring location is exactly what you want.

Regional catalog

Each tile: BirdNET Geomodel v3.0 range filter (top ~800 species for temperate regions, ~1200 for bird-rich tropical/subtropical ones, up to ~3500 for the hyper-diverse Neotropics) + 198 FSD50K sound events + a 27-species cosmopolitan core. Ships _no_dft_fp32 + labels + indices. All bit-exact vs the full model on the species they keep.

Each tile folder also has coverage.png (a map of the region it covers) and metadata.json (species count, covered countries, and the continental group it belongs to).

Tiles are organised by continent below. regional/groups.json lists the same grouping (ordered continents -> tiles) in one file, and each tile's metadata.json carries its group / group_display / group_order, so an application can rebuild these sections without scraping this table.

Europe

region	coverage	classes	fp32 MB
nordic		638	65.0
british-isles		776	68.4
central-europe		873	70.8
baltics		655	65.4
iberia		856	70.4
southern-europe		839	70.0
eastern-europe		739	67.5
western-palearctic		1599	88.7
iceland		591	63.9
svalbard		480	61.1
canary-islands		598	64.0
madeira		459	60.6
azores		426	59.8

Asia

region	coverage	classes	fp32 MB
south-asia-peninsular		879	70.9
indo-gangetic		1406	83.9
himalaya		1407	83.9
japan		799	69.0
china-northeast		877	70.9
china-north-central		976	73.3
china-southeast		1373	83.1
china-southwest		1409	84.0
tibet		1407	83.9

North America

region	coverage	classes	fp32 MB
north-america-east		999	73.9
north-america-west		1002	74.0
canada-alaska		962	73.0

South America

region	coverage	classes	fp32 MB
amazonia		3388	132.7
andes		3535	136.3
eastern-brazil		2184	103.0
southern-cone		1855	95.0
galapagos		336	57.6

Africa

region	coverage	classes	fp32 MB
southern-africa		1002	74.0
reunion		274	56.1
mauritius		272	56.0
seychelles		318	57.2
cape-verde		346	57.8
sao-tome-principe		324	57.3
west-africa		1309	81.5
central-africa		1883	95.6
east-africa		2159	102.4

Oceania

region	coverage	classes	fp32 MB
australia-east		946	72.6
new-zealand		486	61.3
hawaii		478	61.1
new-caledonia		377	58.6

Withdrawn files

The *_int8_arm.onnx files (the global model and one per region) were withdrawn on 2026-11-15. MatMul-only INT8 changes the result too often on real audio: against the fp32 file, top-1 agrees on 82% of 5,560 station windows for the global model and on 75.5% of 94 windows for the nordic tile, which keeps only 71% of the fp32 detections at 0.5 on the same label. It fails the publish gate's int8 floor (at least 95% top-1 agreement where fp32 scores 0.25 or more, at least 90% of fp32 0.5 detections kept, at most 1% int8-only detections). The file stays downloadable for existing installs; use the region's _no_dft_fp32 file instead. They stay in this repo with unchanged bytes and checksums so existing installs keep working, and models.json lists them with withdrawn and a superseded_by pointer to the region's no_dft_fp32 file. Do not use them for new installs.

Usage

Each model takes 5 s of 32 kHz mono audio ([1, 160000]) and outputs a label vector of logits over its species list; pair it with the sibling *_labels.txt (line count matches the logit count). Pick a variant by hardware (table above). Confidence is a softmax over the model's own classes, so a regional tile normalizes over fewer species than the full model; recalibrate detection thresholds per model.

Provenance

Regional slices are gathered from the ProtoPNet head of perch_v2_no_dft.onnx and validated bit-exact against the full model on the species they keep. Perch v2 is by Google; see the license above.