Meeting Abstract

P1.2  Saturday, Jan. 4 15:30  Effects of noise on female preference functions in the acoustically communicating grasshopper Chorthippus biguttulus REICHERT, M.S.; Humboldt University-Berlin michael.s.reichert@hu-berlin.de

The efficiency of animal communication is ultimately limited by the organisms’ perceptual abilities and by errors induced by environmental interference with signal transmission. Noise is a major source of communication errors because it is ubiquitous in nature and because in many cases it can degrade signal characteristics to the point that receivers have great difficulties in recognizing and responding appropriately to relevant signals. In the context of mate choice, noise may interfere with or obscure signal characteristics that are strongly preferred by females. Noise may therefore alter the shape of female preference functions, and thus the strength and direction of selection on male signal characteristics. I measured the effects of noise on the shape of female preference functions in the grasshopper Chorthippus biguttulus, a species that uses acoustic signals to attract mates. Using an automated female testing apparatus, I exposed females to synthetic male signals that were varied in a single signal characteristic while all other characteristics were held constant. I measured preference functions for variation in each characteristic (duration of pauses between syllables, amplitude of syllable onset, amplitude of syllable offset) in the absence of noise and in the presence of three different levels of masking noise. I found that noise indeed has an effect on the shape of female preference functions, but this effect depends on the characteristic examined. Some characteristics are more robust to influences of masking noise than others and thus may be especially important for communication in the natural environment.