The mating calls of six forms belonging to four genera Megophrys,Oreloalax,Scutiger and Leptolalax were recorded in Wawu Mountain National Forest Park,Sichuan Province of China,using cassette tape recorder (Aiwa) and ...The mating calls of six forms belonging to four genera Megophrys,Oreloalax,Scutiger and Leptolalax were recorded in Wawu Mountain National Forest Park,Sichuan Province of China,using cassette tape recorder (Aiwa) and Sony tape with an external microphone.All recordings were analyzed with an IBM PC based 'SIGNAL' software analysis system (Engineering Design,USA).The range of analyzed frequency was set as 0-10 kHz.Acoustic analysis shows that the dominant frequency of L.oshanensis,M.minor,M.sp.,S.(S.)chintingensis,O.omeimontis,and O.schmidti is 4521.9,3456.4,2293.8,1076.5,1071.0 and 1849.4 Hz on average respectively;the note duration is 46.2,90.8,99.6,72.2,78.8 and 110.3 millisecond on average respectively;the note interval is 140.4,253.0,681.4,1517.7,461.3 and 619.5 millisecond on average respectively.One-Way ANOVA analysis indicates that there are significant differences among the analyzed six forms on the dominant frequency,the note duration,and the note interval (P<0.01).Multiple comparisons using Least-Significant Difference (LSD) show that the difference of the dominant frequency between S.(S.) chintingensis and O.omeimontis is not significant (P=0.917>0.05);on the note duration,only L.oshanensis is significantly different from M.minor,M.sp.,O.omeimontis and O.schmidti (P<0.01);on the note interval,L.oshanensis is not significantly different from M.minor,the same with M.sp.versus O.schmidti and O.omeimontis versus O.schmidti (P>0.05).Correlation analysis indicates that there are no significant correlation among the three acoustic characters of dominant frequency,note duration and note interval,and two environmental factors of the elevation and air temperature (P>0.05) except that the note interval is significantly linear correlated with the elevation (r=0.943,P=0.005<0.01).In the light of above,it is suggested that acoustic characteristics of calls are useful in distinguishing forms;the change of the note interval with the elevation may be a kind of strategy of reproduction.展开更多
Multi-component signals contain multiple signal parts expressed in the same physical modality. One way to identify individual components is if they are produced by different physical mechanisms. Here, I studied the me...Multi-component signals contain multiple signal parts expressed in the same physical modality. One way to identify individual components is if they are produced by different physical mechanisms. Here, I studied the mechanisms generating acoustic signals in the courtship displays of the Calliope hummingbird Stellula calliope. Display dives consisted of three synchronized sound elements, a high-frequency tone （hfl）, a low frequency tone （lft）, and atonal sound pulses （asp）, which were then followed by a frequency-modulated fall. Manipulating any of the rectrices （tail-feathers） of wild males impaired production of the lft and asp but not the hfl or fall, which are apparently vocal. I tested the sound production capabilities of the rectrices in a wind tunnel. Single rectrices could generate the lft but not the asp, whereas multiple rectrices tested together produced sounds sitlfilar to the asp when they fluttered and collided with their neighbors percussively, representing a previously unknown mechanism of sound production. During the shuttle display, a trill is generated by the wings during pulses in which the wingbeat frequency is elevated to 95 Hz, 40% higher than the typical hovering wingbeat frequency. The Calliope hummingbird courtship displays include sounds produced by three independent mechanisms, and thus include a minimum of three acoustic signal components. These acoustic mechanisms have different constraints and thus potentially contain different messages. Producing multiple acoustic signals via multiple mechanisms may be a way to escape the constraints present in any single mechanism .展开更多
文摘The mating calls of six forms belonging to four genera Megophrys,Oreloalax,Scutiger and Leptolalax were recorded in Wawu Mountain National Forest Park,Sichuan Province of China,using cassette tape recorder (Aiwa) and Sony tape with an external microphone.All recordings were analyzed with an IBM PC based 'SIGNAL' software analysis system (Engineering Design,USA).The range of analyzed frequency was set as 0-10 kHz.Acoustic analysis shows that the dominant frequency of L.oshanensis,M.minor,M.sp.,S.(S.)chintingensis,O.omeimontis,and O.schmidti is 4521.9,3456.4,2293.8,1076.5,1071.0 and 1849.4 Hz on average respectively;the note duration is 46.2,90.8,99.6,72.2,78.8 and 110.3 millisecond on average respectively;the note interval is 140.4,253.0,681.4,1517.7,461.3 and 619.5 millisecond on average respectively.One-Way ANOVA analysis indicates that there are significant differences among the analyzed six forms on the dominant frequency,the note duration,and the note interval (P<0.01).Multiple comparisons using Least-Significant Difference (LSD) show that the difference of the dominant frequency between S.(S.) chintingensis and O.omeimontis is not significant (P=0.917>0.05);on the note duration,only L.oshanensis is significantly different from M.minor,M.sp.,O.omeimontis and O.schmidti (P<0.01);on the note interval,L.oshanensis is not significantly different from M.minor,the same with M.sp.versus O.schmidti and O.omeimontis versus O.schmidti (P>0.05).Correlation analysis indicates that there are no significant correlation among the three acoustic characters of dominant frequency,note duration and note interval,and two environmental factors of the elevation and air temperature (P>0.05) except that the note interval is significantly linear correlated with the elevation (r=0.943,P=0.005<0.01).In the light of above,it is suggested that acoustic characteristics of calls are useful in distinguishing forms;the change of the note interval with the elevation may be a kind of strategy of reproduction.
基金Acknowledgments I thank S. Weinstein, A. Varma, and T. Feo for assistance in the field L. Benedict and T. Libby for use of equipment, J. Brown for accommodations, and G. Weston-Murphy for assistance with the wind tunnel. Walter Nussbaumer kindly allowed use of a photo. The manuscript was improved by comments from T. Feo and two anonymous reviewers. The research was supported by the MVZ and National Science Foundation IOS-090353 to R. Prum.
文摘Multi-component signals contain multiple signal parts expressed in the same physical modality. One way to identify individual components is if they are produced by different physical mechanisms. Here, I studied the mechanisms generating acoustic signals in the courtship displays of the Calliope hummingbird Stellula calliope. Display dives consisted of three synchronized sound elements, a high-frequency tone （hfl）, a low frequency tone （lft）, and atonal sound pulses （asp）, which were then followed by a frequency-modulated fall. Manipulating any of the rectrices （tail-feathers） of wild males impaired production of the lft and asp but not the hfl or fall, which are apparently vocal. I tested the sound production capabilities of the rectrices in a wind tunnel. Single rectrices could generate the lft but not the asp, whereas multiple rectrices tested together produced sounds sitlfilar to the asp when they fluttered and collided with their neighbors percussively, representing a previously unknown mechanism of sound production. During the shuttle display, a trill is generated by the wings during pulses in which the wingbeat frequency is elevated to 95 Hz, 40% higher than the typical hovering wingbeat frequency. The Calliope hummingbird courtship displays include sounds produced by three independent mechanisms, and thus include a minimum of three acoustic signal components. These acoustic mechanisms have different constraints and thus potentially contain different messages. Producing multiple acoustic signals via multiple mechanisms may be a way to escape the constraints present in any single mechanism .
