Talk Abstracts of Symposium 2023

Laurel Symes

Assistant Director, K. Lisa Yang Center for Conservation Bioacoustics

Passive acoustic monitoring of avian communities and habitats

Sound is an important tool for surveying and monitoring bird populations. For many years, point count surveys and other types of acoustic censuses have provided detailed information about bird populations. More recently, advances in acoustic recording and data storage technology have made it possible to complement human surveys with passive acoustic monitoring (the use of unattended recording devices to capture long recordings from an environment).

In this talk, I will present recent research conducted with passive acoustic monitoring, highlighting the range of questions and scales that are enabled by the approach. I will use these examples to discuss the contexts where passive acoustic monitoring provides valuable extensions to human surveys, as well as limitations of the technology. In addition to presenting scientific findings, I will provide a practical introduction to passive acoustic monitoring including equipment selection and deployment, data management and curation, and analysis approaches. In doing so, I will highlight resources that are available for new practitioners, as well as emerging tools, such as machine learning based analysis of recordings.

Camila Gomez M

Director of education and training, SELVA

Colombia Resurvey Project – Assessing changes in bird communities over a century of landscape transformation

110 years ago, naturalists from the American Museum of Natural History led a series of expeditions to document bird diversity and abundance across a broad region of Colombia. Information from those expeditions exists mostly in the form of collection specimens, and as a compilation in a book written by Frank Chapman in 1917. Between 2019 and 2021 we resurveyed 6 regions that had been visited by Chapman and carried out standardized observations, as well as specimen collection, to document how bird communities have changed in this period. Our results are striking in terms of species composition and turnover. Ecosystem functionality, based on bird diversity, has changed radically even in regions where habitat transformation has not been that great. This project has opened a window to the past and will hopefully serve as a tool to continue monitoring variations in bird composition and ecosystem health towards the future.