The Avian Vocalizations Center at Michigan State University, or AVoCet, offers free downloads of bird sounds from around the world, photos of the birds recorded and links to other online bird call collections, a university release said Tuesday.
AVoCet offers more than 10,200 recordings from over 3,190 species in 45 countries, "and that's growing quickly," Pamela Rasmussen, an assistant professor of zoology, said.
Rasmussen has personally recorded on all the continents for the project. Her work in the Philippines alone netted 597 recordings of 120 species, many of which are threatened, the university said.
Almost all species of birds make sounds of some type and some 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.
Digital technology has revolutionized birding, Rasmussen said, allowing enthusiasts and professionals to more easily record, share and play bird calls.
A comprehensive collection of bird sounds can yield better understanding of habitats, ranges and habits for biodiversity studies, Rasmussen said.
"It's very difficult to see birds in a tropical rain forest, but not difficult to hear and recognize them."