Georgia Southern University
During the first quarter of 2019, my Spring semester Field Biology class and I officially launched the SInGS (Singing Insects of Georgia Southern) project. During the initial phase, students learned basic GPS skills, how to describe habitats, and how to set up and install Song Meters. We identified five sites on the Statesboro campus that represented different habitat types (woodland, wetland, sand hill, disturbed, and urban; Fig. 1), and installed one Song Meter at each site on February 21 (Fig. 2). We set the meters to record five minutes every hour at a sample rate of 44,1000 Hz. We also set up a schedule to swap out the batteries and SD cards on a monthly basis (Fig. 3).
In the classroom, students learned the mechanisms and functions of sound production in animals, how to describe and analyze animal sounds, and how to use the Open Source audio analysis software Audacity to facilitate the location and characterization of insect calls. An earlier class surveyed the University of Florida’s “Singing Insects of North America” web site and constructed a list of 92 species of orthopterans (44 crickets and 48 katydids); this semester's class had the formidable task of characterizing the songs of each of these species (trills, ticks, chirps; peak frequencies, duration, complexity, variability, etc.) and assembling this information into a novel, spreadsheet-based identification aid. We engaged in a trial run of this Audacity-spreadsheet approach to audio identification by having the entire class attempt to identify two species of orthopterans in the same five-minute file. Based on the outcomes of this trial run, we tweaked the identification protocols as well as the guide itself. In late April students will each work through 24-25 files, identifying any singing insects they hear/see and identifying patterns of change over time (during a day, across the season) and differences among the five sites. During the April maintenance visit to each site, students will collect specimens using sweep nets, beater trays, and pitfall traps to compare and contrast with the audio surveys.
Fig. 1: Five Song Meter installation sites on the Georgia Southern University Statesboro campus. A: disturbed (woodland bush-hogged, leaving a clearing with rapid-growing brambles and other early succession plants. B: sand hill. C: pine woodland. D: wetland. E: urban campus.
Fig. 2: Field Biology students and professor finish attaching a Song Meter to a tree adjacent to a pond (offscreen) in the wetland site. Pictured from left to right: Courtney Weekley, Kayla Dunn (obscured), Kianna Reed, and Alan Harvey. Photo by Kensley Depenhart.
Figure 3: Field Biology students replacing batteries and SD card during monthly maintenance of Song Meters. Pictured from left to right: Dillon Hernandez and Brandon Jarvis. Photo by Alan Harvey.