What is the difference with Merlin?

[cadop]

It would be helpful to add in the readme a clarification with BirdNET vs Merlin, as they seem to have the same use of sound ID, both have theCornellLab branding. There seems to be more information around the "Merlin" app, it seems Merlin doesn't provide all of the source data, just a subset through the library. Are these the same projects on the backend?

[kahst]

Yes and no. Both apps build on core principles that were originally developed through collaborative work at the Lab of Ornithology and Chemnitz University - such as using 3-second audio chunks, spectrogram-based CNNs, focal-follow training data, and extensive augmentation. However, the two projects are entirely independent in terms of the teams, workflows, and long-term goals behind them.

BirdNET is developed in Chemnitz, Germany, while Merlin is developed in Ithaca, USA. Although both efforts receive support from the Lab of Ornithology, that funding connection is essentially the only shared element.

The BirdNET team operates with an “open source first” philosophy aimed at enabling scalable, global bioacoustic monitoring and supporting the broader research community. In contrast, the Merlin team works in a fully closed-source environment and does not share models, results, or resources externally. These fundamentally different approaches naturally lead to differences in transparency, collaboration, and ultimately in how the projects evolve.