Dominant frequency.—A dominant [band of of frequencies] cuts across the harmonics of the fundamental, obscuring the harmonic pattern and generally shifting upward in frequency. The midpoint of this band is measured at the terminal border as the dominant frequency. As with the fundamental frequency, only the normal primary notes were utilized in the comparisons ([Table 5], [Fig 8]).
Fig. 7. Variation in the fundamental frequency of the normal primary notes in the Hyla microcephala group. The horizontal lines = range of variation, vertical lines = mean, solid bars = twice the standard error of the mean, and open bars = one standard deviation. The number of specimens in each sample is indicated in parentheses after the name of the taxon.
The two subspecies of H. microcephala agree more closely in this parameter than in fundamental frequency. The overlap is great, but the difference between the means is significant at the 0.001 level (t = 3.658). The calls of both subspecies completely overlap that of robertmertensi in this parameter, but the difference between the means is significant at the 0.001 level. The calls of H. phlebodes and H. sartori overlap considerably in this characteristic, although the difference between the means is significant at the 0.001 level (t = 7.504) ([Fig. 9]). The call of neither species overlaps those of H. microcephala and robertmertensi.
Fig. 8. Variation in the mid-point of the dominant frequency band of the normal primary notes in the Hyla microcephala group. The horizontal lines = range of variation, vertical lines = mean, solid bars = twice the standard error of the mean, and open bars = one standard deviation. The number of specimens in each sample is indicated in parentheses after the name of the taxon.
