A strongly annotated passive acoustic dataset for tropical bird monitoring

This work is under submission to the Bioacoustics Data collection of Scientific Data journal.

Pipeline for bird vocalization detection and classification from audio recordings using spectrogram-based deep learning models. Built on top of the PytorchWildlife library, it covers data downloading, annotation creation, dataset preparation, model training, cross-validation, and evaluation.

Dataset: PteroSet (Zenodo)

Quick Start

1. Installation

pip install -r requirements.txt

2. Download Data

From the data/ directory:

cd data
python download_data.py

This downloads and extracts the PteroSet dataset from Zenodo into the data/ directory. The Zenodo record contains the following files:

• audios.zip — Audio recordings
• labels.zip — RAVEN Pro annotation files
• annotations_identification.json — Identification-level annotations (COCO format)
• annotations_species.json — Species-level annotations (COCO format)
• metadata.csv — Audio file metadata
• species.csv — Species reference data
• checkpoints.zip — Pretrained model checkpoints

Optional arguments:

Argument	Description	Default
--output-dir DIR	Directory to save and extract data	data/
--keep-zip	Keep ZIP files after extraction	off
--workers N	Parallel connections per file	8

3. Create Annotations

Precomputed annotation files (annotations_species.json and annotations_identification.json) are available directly from the Zenodo record. This step is only needed if regenerating from raw labels.

From the data/ directory:

# Species-level: only annotations with species determination
# Categories = species codes (e.g., "CYAVIO"), supercategory = identification
python data_reader.py --annotation_level species

# Identification-level: all annotations included
# Categories = identification (e.g., "AVEVOC"), supercategory = type
python data_reader.py --annotation_level identification

Outputs annotations_species.json or annotations_identification.json in COCO format.

4. Configuration

data/config.yaml contains all experiment settings: paths, audio parameters, spectrogram configuration, training hyperparameters, and data split ratios. Key defaults:

• Audio: 48 kHz sample rate, 5-second windows with 4-second overlap
• Spectrogram: 224 mel bins, 2048 FFT, 512 hop length
• Training: ResNet18 backbone, binary classification (Birds / No Birds), batch size 32
• Splits: Leave-one-project-out with 5 projects (MAP1, PPA1-PPA4)

5. Prepare Dataset

# Full pipeline (stats, windows, segment_windows, spectrograms, splits)
python prepare_dataset.py --config data/config.yaml

# Or run specific steps
python prepare_dataset.py --config data/config.yaml --steps windows segment_windows spectrograms

Available steps:

• stats — Display dataset statistics
• windows — Build sliding windows from annotations
• segment_windows — Filter windows to respect segment boundaries (removes windows that cross 10 s boundaries)
• spectrograms — Compute mel spectrograms on GPU
• splits — Create leave-one-project-out folds (segmented windows, non-overlapping test sets)

6. Train Model

# Single train/val/test split
python train.py --config data/config.yaml \
    --train_csv train_split.csv \
    --val_csv val_split.csv \
    --test_csv test_split.csv

# Cross-validation across all 5 folds
python train.py --config data/config.yaml \
    --cross_validation --fold_dir data/folds_segmented

# Train a specific fold
python train.py --config data/config.yaml \
    --cross_validation --fold_dir data/folds_segmented --fold 0

# Finetune from a pretrained checkpoint
python train.py --config data/config.yaml \
    --ckpt_path pretrained.ckpt --finetune true

7. Evaluate Model

# Evaluate a checkpoint on a test set (no training)
python train.py --config data/config.yaml \
    --ckpt_path checkpoint.ckpt \
    --test_csv test_split.csv

# Aggregate cross-validation results and plot precision-recall curves
python plot_cv_results.py \
    --fold_dir data/folds_segmented \
    --config data/config.yaml \
    --checkpoint_dir checkpoints

Project Structure

birds_bioacoustics/
├── data/
│   ├── config.yaml              # Central configuration
│   ├── download_data.py         # Download dataset from Zenodo
│   ├── data_reader.py           # Parse RAVEN labels into COCO annotations
│   └── data_stats.py            # Dataset statistics and visualizations
├── train.py                     # Model training and evaluation
├── prepare_dataset.py           # Dataset preparation pipeline
├── plot_cv_results.py           # Cross-validation results and PR curves
├── requirements.txt             # Python dependencies
├── LICENSE.txt                  # MIT License
└── SECURITY.md                  # Microsoft security policy

Pipeline Overview

Audio files (48 kHz) + RAVEN label files
  → Annotations (COCO JSON)
  → Sliding windows (5s, 4s overlap)
  → Segmented windows (filter boundary-crossing windows)
  → Mel spectrograms (.npy)
  → Leave-one-project-out CV splits (non-overlapping test)
  → ResNet classifier (binary or multiclass)
  → Evaluation with aggregated metrics

For inference on new audio, see the PytorchWildlife library.