摘要:

Blue tits, as many other species, show much geographic variation in their songs. In blue tits, songs that include a trill (series of rapidly repeated notes) are widespread on the European mainland, but have not been reported in North Africa or the Canary Islands. We studied song structure of two blue tit populations from the French Mediterranean that are exposed to large differences in local selection pressures (food, vegetation, social factors). Songs from populations on the European mainland and the island of Corsica differed much in syntax, tempo, frequency, and the incidence of trills. The observed population differences could potentially be caused by a combination of different factors, including biotic and abiotic habitat characteristics, body size, and cultural drift. We suggest that songs without trill are acoustically adapted for transmission in habitats where the local breeding density of great tits is low. In addition, we suggest that songs with trill may reflect a character shift, to minimise territorial interactions with great tits.

ISSN:0952-4622    

DOI:10.1080/09524622.1998.9753376

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

An acoustic signal is altered by various processes during long-range propagation. Birds may use degraded sound features to assess the distance of the emitter. To know which temporal sound features are susceptible to be used by birds for ranging, we performed a study using natural and synthetic acoustic signals which had different temporal sound degraded characteristics, i.e amplitude and frequency modulations and sound-silence alternations.

ISSN:0952-4622    

DOI:10.1080/09524622.1998.9753377

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

We describe the vocal repertoire of the Asian cricket frogRana nicobariensisfor the first time. Three structurally-distinct call types exist: advertisement calls, aggressive calls and encounter calls. Compound calls consisting of both advertisement and aggressive elements were also recorded. A remarkable feature of communication in this species is the highly variable advertisement call which shows a 20-fold variation in duration, comprising 1–25 notes. In natural choruses, the duration of the advertisement call is inversely related to the distance between a focal male and its closest calling neighbour. In playback experiments, males clearly responded to stimuli containing different numbers of notes by adjusting the number of notes emitted. However, they did not match the stimulus precisely, and were inhibited from calling by a stimulus consisting of a continuous train of notes. Different proportions of each call type were recorded during playbacks at different distances; aggressive and encounter calls were increasingly emitted at closer distances. Our results suggest that a graded communication system has evolved inRana nicobariensis, in which the best call for a male to use at any moment depends on the type of calls being emitted by other males in the chorus.

ISSN:0952-4622    

DOI:10.1080/09524622.1998.9753378

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

ISSN:0952-4622    

DOI:10.1080/09524622.1998.9753379

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

ISSN:0952-4622    

DOI:10.1080/09524622.1998.9753380

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

ISSN:0952-4622    

DOI:10.1080/09524622.1998.9753381

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

ISSN:0952-4622    

DOI:10.1080/09524622.1998.9753382

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

ISSN:0952-4622    

DOI:10.1080/09524622.1998.9753383

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

ISSN:0952-4622    

DOI:10.1080/09524622.1998.9753375

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor