Echolocation calls of 10 Chinese rhinolophid species were recorded to investigate the relationship between morphology and echolocation signals. All horseshoe bats use FM-CF-FM calls. Rhinolophus rex calls at 23.7 kHz, the lowest frequency in this genus. Call frequency was not correlated with body mass (P=0.200, 9 species). Close negative relationships were found between call frequency and ear length (r=-0.942, P<0.001) and also between call frequency and forearm length (r=-0.696, P<0.05). Residual analysis was carried out to remove the influence of other morphological features. After calculating ear length, forearm length residuals were not significantly related to call frequency (r=-0.095, P=0.808). The significance of the correlation between ear length and call frequency was slightly lowered (r=-0.642, P=0.062) after “removing” the influence of forearm length. Ear length, therefore, was a better predictor of call frequency than forearm length [Acta Zoologica Sinica 49(1):128-133,2003].
