The Powdermill Avian Research Center (PARC) is advancing the techniques and technologies of avian bioacoustical monitoring, research used to aid population surveys and songbird conservation.
Most songbirds migrate at night, and many variables affect the timing, duration, and location of each night’s migration. Traditional field counts and banding efforts are often slow to detect long-term population trends, and often only after those trends have become pronounced. Bioacoustical monitoring can aid significantly by opening a new window on our understanding of bird migration.
PARC’s Bioacoustics Lab
At PARC, our bioacoustics lab takes advantage of the decades of experience and expertise available at our bird banding station. Selected songbirds which have been captured for banding spend a short additional time at PARC in a specially constructed recording booth.
Most songbirds emit short flight notes during their nocturnal migrations. By playing vocalizations from an archive of bird calls, return notes from the captured birds are elicited and recorded. Bird calls recorded in our booth are far cleaner than those captured in the field, and PARC is building a remarkable library of calls which will be of use to researchers and in developing automated population survey techniques.
Raven interactive sound analysis software, developed by Cornell Lab of Ornithology aids in recording isolating, and analyzing these acoustic signatures.
A discovery made by PARC’s Bioacoustics Lab Supervisor, Michael Lanzone, resulted in the design of the “acoustic cone” used to record the banded birds. This has resulted in a rapid increase in the number of species for which flight calls and variation in these calls are known.
Bioacoustic Bird Counts
One of the biggest practical applications of the bioacoustic data gathered at PARC involves establishing field recording stations, from which nocturnal recordings can be compared to the flight call database, providing new and potentially far reaching techniques for monitoring populations and migration characteristics.
Field microphones feed captured sounds to computers which operate from sunset to sunrise, after which the recordings are analyzed for flight call notes. Once isolated, the calls are individually saved by date, time, and frequency, as well as being sorted into species groups. Analysis then allows us to determine the minimum number of individuals, temporal patterns of flight calling, and peak passage times.
Field microphones developed at PARC use readily available, commercial components. The goal was to fabricate an effective microphone assembly that would be within the means of birding enthusiasts, Boy Scout troops, and high school classes, as well as ensure that research stations would need minimal investment to begin capturing quality vocalizations from migrating nocturnal bird species. Contact PARC for more information.
With its bioacoustic program, PARC is playing a role in the advanced application of bioacoustics to the monitoring of geographically remote songbird populations in North America and, eventually, around the world.