{'fraction_non_alphanumeric': 0.04576043068640646, 'fraction_numerical': 0.03633916554508748, 'mean_word_length': 4.995967741935484, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Traffic Noise Affects the Characteristics of Echolocation Pulse in Asian Parti-Colored Bat, Vespertilio sinensis

Ambient noise is treated as an evaluative pressure on bats since it can reduce their detective ability for audio message. Vertebrates use a number of strategies to avoid signal masking by humam making noise, including increasing call duration, frequency and amplitude. Here, we tested whether traffic noise influenced echolocation behavior in Asian parti-colored bat(Vespertilio sinensis) under natural condition. We recorded the echolocation pulses from two groups of bats while flying in areas with different traffic noise levels. We recorded 143 pulses at the site in which the mean amplitude of noise was 73.7 d B and 212 pulses at another site in which the mean amplitude of noise was 58.6 d B. To characterize echolocation pulse, we measured six spectral parameters(duration, starting frequency, peak frequency, ending frequency, bandwidth and slope). The results showed that only pulse frequency was shifted upward in respond to high traffic noise, including starting frequency(T test: t353 = 13.67, P 0.001), peak frequency(Mann-Whitney U: P 0.001), ending frequency(Mann-Whitney U: P 0.001) and bandwidth(T test: t353 = 4.30, P 0.05), but not in call duration(T test: t353 = 0.017, P 0.05) and slope(Mann-Whitney U: P 0.05)(Table 1). These results indicate that Asian parti-colored bat can modify the features of echolocation pulses in traffic noisy environments.