  Passive acoustic monitoring offers a scalable, non-invasive method for
tracking global biodiversity and anthropogenic impacts on species. Although
deep learning has become a vital tool for processing this data, current models
are inflexible, typically cover only a handful of species, and are limited by
data scarcity. In this work, we propose BioLingual, a new model for
bioacoustics based on contrastive language-audio pretraining. We first
aggregate bioacoustic archives into a language-audio dataset, called
AnimalSpeak, with over a million audio-caption pairs holding information on
species, vocalization context, and animal behavior. After training on this
dataset to connect language and audio representations, our model can identify
over a thousand species' calls across taxa, complete bioacoustic tasks
zero-shot, and retrieve animal vocalization recordings from natural text
queries. When fine-tuned, BioLingual sets a new state-of-the-art on nine tasks
in the Benchmark of Animal Sounds. Given its broad taxa coverage and ability to
be flexibly queried in human language, we believe this model opens new
paradigms in ecological monitoring and research, including free-text search on
the world's acoustic monitoring archives. We open-source our models, dataset,
and code.
