Bird call database nests online

The Avian Vocalizations Center at Michigan State University, or AVoCet,offers free downloads of bird sounds from around the world. It also features sonograms that visually chart the sounds, photos of birds recorded, Google Earth maps of recording locations and links to other online sound collections.

More than 10,200 recordings from over 3,190 species in 45 countries are now available on AVoCet, "and that's growing quickly," said Pamela Rasmussen, an assistant professor of zoology and assistant curator at the MSU Museum. "Soon recordings and their data from many more species and areas will be available for download from AVoCet."

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This is a recording of a Red-tailed hawk made by Pamela Rasmussen in Maryland and now downloadable from the AVoCet database. Credit: Pamela Rasmussen/AVoCet

There are, after all, 10,000 bird species, all of which make sounds of some type. Many birds, such as cardinals, even sing in regional dialects. Some birds have huge vocabularies – a single male Brown Thrasher is known to give 2,000 different notes.

Author of an exhaustive reference work on the birds of South Asia, Rasmussen has personally recorded on all the continents for this project. Her work in the Philippines alone netted 597 recordings of 120 species, many of which are threatened. Some of those sound types are not publicly available anywhere other than AVoCet.

AVoCet also contains recordings made around the world so far by 65 others, including local ornithologists, professional guides and MSU students from Rasmussen's study abroad and ornithology courses. Zoology department programmer/analyst Patrick Bills built the database and Web site and undergraduate students also contributed.

Digital technology has revolutionized birding, Rasmussen explains, allowing enthusiasts and professionals to more easily record, share and play bird calls. Online access to the AVoCet library allows easy access to sounds, photos and other supporting information via computer and Internet-connected mobile devices.

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This is the sonogram corresponding to a recording of a Red-tailed hawk made by Pamela Rasmussen. Credit: Pamela Rasmussen/AVoCet

The ability to identify birds vocally is crucial for monitoring bird movements and populations, including such popular events as the annual Christmas bird counts organized across the country. A comprehensive collection of bird sounds can yield better understanding of habitats, ranges and habits, while allowing more efficient and thorough biodiversity studies, Rasmussen said. "It's very difficult to see birds in a tropical rainforest, but not difficult to hear and recognize them."

Oriented to the scientific community, AVoCet maintains rigorous scholarly standards. Whenever possible, recordings are accompanied by photos and sighting observations that enable independent evaluation, Rasmussen said. Scientists can then accurately map avian biodiversity and perhaps identify new species.

"We know that certain species will go extinct in the near future and, sadly, there's not a lot that can realistically be done about it," Rasmussen said. "However, ornithologists and birders do now have the opportunity to document virtually all the species of birds out there in one way or another, and one major goal of AVoCet is to contribute to this effort."

Provided by Michigan State University