9 s of calling song, male from Leon County, Fla., 25.4°C; smooth trill. Dominant frequency 4.8 kHz. (WTL482-189b)
This spectrogram is a 2 s excerpt of the 9 s audio file accessible above. The excerpt begins at 1.5 s.
22 s of calling song, male from Pope County, Ill., 24.0°C; stuttery trill. Dominant frequency 4.9 kHz. (WTL482-61)
This spectrogram is a 2 s excerpt of the 22 s audio file accessible immediately above. the excerpt begins at 0 s.
7 s of courtship song, male from Fla. Recording by D. A. Gray; used by permission.
This spectrogram is a 1 s excerpt of the 7 s audio file accessible above. The excerpt begins at 2 s.
Song:
The trills of G. rubens vary in the regularity of the pulse sequences. When the pulses are interrupted by brief pauses lasting as long as a single pulse or a little longer, the trill sounds "stuttery." When the sequence of pulses is uninterrupted, the trill is "smooth." In some populations, stutter trilling is common. In others it is rare. Captured males do not always produce a single type of trill. The origin and significance of the variation in the smoothness of the trills is unknown.
Identification:
This species and Gryllus texensis are the only trilling Gryllus in the eastern United States. (All others are chirpers.) G. texensis tends to produce shorter, more regular trills than G. rubens, but where they occur together, the two can be distinguished reliably only by the pulse rates of their calling songs—after the rates have been adjusted for temperature. Even though the two species are (thus far) almost indistinguishable morphologically (Gray et al. 2001) and readily hybridize in the laboratory, they maintain their integrity in the field (Walker 1998, 2000). A key to the adult males of native US Gryllus is in Weissman and Gray (2019).
