摘要:

The mating calls of the Iberian midwife toads,A.o. boscaiandA. cisternasiishow clear differences. The calls ofA.o. boscaihave a shorter duration (104.8ms) and a lower fundamental frequency (1.33 kHz) than those ofA. cisternasii(172.0 ms and 1.45 kHz), between 12° and 16°C. In both species signal duration was found to be influenced by temperature.

ISSN:0952-4622    

DOI:10.1080/09524622.1989.9753109

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A phylogeny of guenons was drawn up from the analysis of the acoustic structure of their cohesion, contact and alarm calls, as well as of the loud calls of the adult males. The plesiomorphic or apomorphic state of every acoustic parameter retained was inferred from comparisons with calls given by papionines and/or colobines. A cladistic method was used for analysing a matrix of species by character.

ISSN:0952-4622    

DOI:10.1080/09524622.1989.9753110

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Distress calls are signals effective over a long distance. They are well known to evoke interspecific reactions. We suggest that the interspecificity phenomenon results from the use of similar laws of decoding by the species concerned. These laws must take into account the transmission channel which always has a great influence on long-range communication. We tested our hypothesis by broadcasting simplified synthetic calls to two species of birds: the herring gull and the starling. The various calls differed in terms of frequency modulation (FM). Two main conclusions emerged from this series of tests:

ISSN:0952-4622    

DOI:10.1080/09524622.1989.9753111

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

“Pure tones” are a distinctive acoustic feature of many birdsongs. Recent research on songbird vocal physiology suggests that such tonal sounds result from a coordinated interaction between the syrinx and a vocal filter, as demonstrated by the emergence of harmonic overtones when a bird sings in helium. To investigate the communicative significance of vocal tract filtration in the production of birdsong, we used field playback experiments to compare the responses of male swamp sparrowsMelospiza georgianato normal songs and those same songs recorded in helium. We also measured responses to pure tone songs that had been shifted upward in frequency to match the average spectra of those songs with added harmonics. Male sparrows were significantly more responsive to the playback of normal songs than to either helium songs with added harmonics or frequency- shifted pure tone songs. Songs with harmonics retained a high degree of salience, however. We conclude that explanations for the occurrence of tonal sounds in birdsongs must consider perceptual attributes of songs as communicative signals, as well as problems of song production and transmission.

ISSN:0952-4622    

DOI:10.1080/09524622.1989.9753112

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

In two-choice discrimination experiments, females ofHyperolius marmoratuspreferred the calls of lower frequency of the pair of stimuli. This preference was not shown in mating patterns observed in natural choruses, but is when females are phonotactically orienting in small choruses in an experimental enclosure. With an increase in chorus size, the mating pattern shifts from size-based, non-random (with some evidence of size-assortative) mating to random mating. This is the first time that frequency-based mate-choice by female anurans has been associated with chorus size, and hence with the sonic complexity of the acoustic environment.

ISSN:0952-4622    

DOI:10.1080/09524622.1989.9753113

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0952-4622    

DOI:10.1080/09524622.1989.9753114

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0952-4622    

DOI:10.1080/09524622.1989.9753115

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0952-4622    

DOI:10.1080/09524622.1989.9753116

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0952-4622    

DOI:10.1080/09524622.1989.9753117

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0952-4622    

DOI:10.1080/09524622.1989.9753118

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor