The Significance of Song Variation in a Population of Darwin's Finches

Behaviour ◽  
1984 ◽  
Vol 89 (1-2) ◽  
pp. 90-116 ◽  
Author(s):  
B.R. Grant

AbstractMales of Geospiza conirostris, the large cactus finch, on Isla Genovesa, Galápagos, sing a single, precisely copied song. There are two song types in the population, and these are sub-divided into 3 and 5 discrete song sub-types respectively. Adult males sing only one song sub-type throughout life. Sons sing the same song sub-type as their fathers' and do not copy the songs of either natal or breeding territory neighbours. Significantly more of the males holding territories with neighbours of unlike (heterotypic) song type obtain a female than males in territories with no heterotypic neighbour. Pairs in territories with a heterotypic neighbour fledge significantly more young than do pairs in territories with no heterotypic neighbour. Significantly more of those young born on territories with a heterotypic neighbour, that survive to become adults, obtain a mate, than do those surviving young born on territories with no heterotypic neighbour. The data are consistent with the hypothesis that the relative greater importance of song for species recognition in this population has made it advantageous for males to have a single, short, distinct, precisely copied and stable song. The necessity for recognizing both song types as conspecific has produced a unique mating pattern which favours pairs in territories with a heterotypic song neighbour. This allows young to associate visual and auditory cues of father and neighbouring male during the short period of imprinting. A small effective population size, combined with the observation that no female has been known to mate with a male of the same song sub-type as her father's, suggests a possible kin recognition system to avoid inbreeding.

Behaviour ◽  
1998 ◽  
Vol 135 (3) ◽  
pp. 321-342 ◽  
Author(s):  
Douglas Nelson

AbstractWhite-crowned sparrow (Zonotrichia leucophrys) song varies geographically, often forming local 'dialects' in sedentary and short-distance migratory subspecies. In playback experiments males and females can distinguish this variation. Gambel's white-crowned sparrow (Z. L. gambelii) is a long-distance migrant that breeds across subarctic Canada and Alaska. Previous studies identified a wide degree of song variation within local populations of this subspecies. I compared songs recorded in Alaska and Churchill, Manitoba, and found significant differences in acoustic structure. As in other subspecies, the most prominent differences occurred in the terminal trill portion of the song. In a playback experiment to territorial males at Churchill, males gave equivalent strong responses to both Alaska and local gambelii song, significantly weaker responses to mountain white-crowned sparrow (Z. L. oriantha) song, and the weakest responses to heterospecific song. I describe a model of song recognition in which 'dialect recognition' is a component of species recognition. I conclude that as a consequence of differences in the timing of song learning, the subspecies of white-crowned sparrow may differ in the acoustic features that they attend to in song recognition. The diversity of song types at a local level within gambelii populations may interfere with recognizing song differences between populations.


1978 ◽  
Vol 56 (6) ◽  
pp. 1266-1283 ◽  
Author(s):  
M. Ross Lein

Song variation in a population of chestnut-sided warblers (Dendroica pensylvanica) was investigated during 1970–1972 in Hillsboro County, New Hampshire. Five song types, which appear to be shared by all males in the local population, are described and are used differentially by the birds. Two 'accented ending' song types are used primarily by undisturbed males located centrally on their territories. Two 'unaccented ending' song types are used in territorial encounters, or when a male is located peripherally on his territory. The fifth type, 'jumbled song,' is used almost exclusively during territorial encounters. There is no evidence of special association of any of the types with male–female interactions. It is suggested that the song types form a graded series of signals, increasing the efficiency of male–male communication by transmitting more precise messages than would be possible with only a single song type.


The Auk ◽  
2000 ◽  
Vol 117 (1) ◽  
pp. 52-64 ◽  
Author(s):  
Carla Cicero ◽  
Morgan Benowitz-Fredericks

Abstract In contrast to the Swamp Sparrow (Melospiza georgiana) and Song Sparrow (M. melodia), vocal studies of the congeneric Lincoln's Sparrow (M. lincolnii) are essentially lacking. To provide comparative data on song variation in this species, we obtained and analyzed recordings from 58 males (4,537 songs) breeding in montane meadows of the Sierra Nevada and San Bernardino Mountains, California. Males sang from one to six song types, and repertoire size averaged 3.7 types. No two males shared an identical song type. Males varied their types by changing the number of repetitions of a syllable or by adding, deleting, or substituting one or more syllables (i.e. by changing syllable composition). The number of variants, identified on the basis of differences in syllable composition, averaged 2.6 per song type (range 1 to 12). Individual variability was highest in the terminal elements of the song. Production of variants appears to be a process of “open-ended improvisation” of song types. Similarity of songs on the basis of shared syllables, as calculated by simple matching coefficients, showed a strong pattern of concordance with geography. Pairwise similarity declined with increasing distance between meadows, and meadows from different geographic regions clustered separately in a UPGMA tree. Patterns of geographic variation in song of Lincoln's Sparrows are similar to those observed in Song Sparrows and Swamp Sparrows. Song complexity and repertoire size show different evolutionary trends within Melospiza.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10780
Author(s):  
José Martín ◽  
Ernesto Raya-García ◽  
Jesús Ortega ◽  
Pilar López

Kin recognition is a phenomenon with an important function in maintaining cohesive social groups in animals. Several studies have examined parent–offspring recognition in species with direct parental care. Few studies have, however, explored parent–offspring recognition in animals that, at best, only show apparent indirect parental care, such as some reptiles. In this study, we investigated reciprocal parent–offspring recognition in the fossorial amphisbaenian Trogonophis wiegmanni, a viviparous species that shows potential stable ‘family groups’ in the form of parent-offspring long-term associations. We examined whether adult males and females could discriminate via chemical cues between familiar juveniles which associate with them within their family groups, and are potentially their offspring, to that of unfamiliar juveniles, and whether juveniles could discriminate between familiar adult males and females of their family group (probably their parents) and unfamiliar unrelated adults. We measured tongue flick behavior to study chemosensory responses to the scent of conspecifics. We found that adult female amphisbaenians, but not males, could discriminate between scents of familiar and unfamiliar juveniles. Juvenile amphisbaenians did not discriminate between familiar and unfamiliar adult females, but recognize familiar from unfamiliar males. We discuss our results of parent–offspring recognition according to its potential social function in an ecological fossorial context where visibility is limited and chemosensory kin recognition may contribute to the establishment of stable family groups.


The Condor ◽  
2006 ◽  
Vol 108 (2) ◽  
pp. 326-335 ◽  
Author(s):  
David M. Logue

Abstract In many duet-singing songbirds, paired birds combine their song types nonrandomly to form duet songs. Several different behavioral mechanisms could generate nonrandom song type associations in duets. I tested female Black-bellied Wrens (Thryothorus fasciatoventris) for one such mechanism: adherence to a set of rules linking female response songs to male stimulus songs. I call this set of rules a “duet code.” Duets of free-living Black-bellied Wrens were recorded in 2001 and 2002. In 2003 I returned to the same territories and played the male song types from the recorded duets. Females answered male song stimuli as if duetting with the playback speaker. Although the known repertoires of females averaged 8.4 song types, each female sang only a single song type in response to each male song type. Random answering could not account for this pattern, supporting the hypothesis that females abide by duet codes. Females that were still paired with their mates from 2001–2002 answered 100% of their mate's songs with the same song types they had used previously, demonstrating that codes are stable over time. In contrast, females that were new to a territory answered an average of only 18% of their mate's song types with the same song type as the previous female, indicating that duet codes are individually distinctive. Duet participation by female Black-bellied Wrens represents a special kind of animal communication, in which discrete vocal signals consistently elicit discrete vocal responses according to an individually distinctive set of rules.


2017 ◽  
Vol 284 (1864) ◽  
pp. 20171774 ◽  
Author(s):  
Paweł Ręk ◽  
Robert D. Magrath

Many group-living animals cooperatively signal to defend resources, but what stops deceptive signalling to competitors about coalition strength? Cooperative-signalling species include mated pairs of birds that sing duets to defend their territory. Individuals of these species sometimes sing ‘pseudo-duets’ by mimicking their partner's contribution, but it is unknown if these songs are deceptive, or why duets are normally reliable. We studied pseudo-duets in Australian magpie-larks, Grallina cyanoleuca , and tested whether multimodal signalling constrains deception. Magpie-larks give antiphonal duets coordinated with a visual display, with each sex typically choosing a different song type within the duet. Individuals produced pseudo-duets almost exclusively during nesting when partners were apart, but the two song types were used in sequence rather than antiphonally. Strikingly, birds hid and gave no visual displays, implying deceptive suppression of information. Acoustic playbacks showed that pseudo-duets provoked the same response from residents as true duets, regardless of whether they were sequential or antiphonal, and stronger response than that to true duets consisting of a single song type. By contrast, experiments with robot models showed that songs accompanied by movements of two birds prompted stronger responses than songs accompanied by movements of one bird, irrespective of the number of song types or singers. We conclude that magpie-larks used deceptive pseudo-duets when partners were apart, and suppressed the visual display to maintain the subterfuge. We suggest that the visual component of many species' duets provides the most reliable information about the number of signallers and may have evolved to maintain honesty in duet communication.


The Condor ◽  
2001 ◽  
Vol 103 (4) ◽  
pp. 855-861
Author(s):  
Donald E. Kroodsma ◽  
Krista Wilda ◽  
Viviana Salas ◽  
Roldan Muradian

Abstract Evidence from two Cistothorus wrens (C. palustris, C. platensis) has suggested that repertoire size increases with population density and that song imitators are more likely to be site faithful than are song improvisers. We tested these two ideas on a third species, C. meridae, an endemic to the Venezuelan Andes. Of the three Cistothorus wrens, song repertoire sizes of male Mérida Wrens are the smallest, ranging from 18 to 27 song types per male; Mérida Wrens are also most likely to repeat each type several times before switching to a new type. Density of Mérida Wrens was also lowest, from 0.4 to 2.0 territories per 10 ha. These wrens are highly site faithful, with marked microgeographic song variation. Female Mérida Wrens also sing. Overall, data from the Mérida Wren support the ideas that, among Cistothorus wrens, song repertoire sizes increase with population density and site faithfulness promotes song imitation. Variación en el Canto en Cistothorus, con Énfasis en C. meridae Resumen. La evidencia proveniente de dos especies del género Cistothorus (C. palustris, C. platensis) sugiere que el tamaño del repertorio aumenta con la densidad poblacional y que los imitadores de cantos tienen una mayor probabilidad de ser territoriales que los que improvisan. Estas dos ideas fueron probadas en una tercera especie endémica de los Andes venezolanos, C. meridae. El tamaño del repertorio del canto de esta especie, con 18 a 27 tipos de canto por macho, es el más pequeño de estas tres especies. C. meridae también tiene una mayor probabilidad de repetir cada tipo de canto varias veces antes de cambiar a un tipo nuevo. La densidad de C. meridae también fue la menor, con 0.4 a 2.0 territorios por cada 10 hectáreas. C. meridae es muy territorial, con una marcada variación microgeográfica en las cantos. Las hembras de esta especie también cantan. En resumen, estos datos apoyan las ideas de que en el género Cistothorus, el tamaño del repertorio del canto aumenta con la densidad poblacional y que la territorialidad promueve la imitación de cantos.


The Condor ◽  
2002 ◽  
Vol 104 (4) ◽  
pp. 848-854 ◽  
Author(s):  
Jill A. Soha ◽  
Carol Whaling

Abstract We examined the contribution of individual song phrases to territorial behavior in Nuttall's White-crowned Sparrows (Zonotrichia leucophrys nuttalli) in the Bodega, California, dialect area. We presented territorial adult males with playbacks of five song types: local conspecific song, three single phrase types of local conspecific song, and Song Sparrow (Melospiza melodia) song. Local conspecific song evoked the strongest response, measured in latency to flight, number of flights, average and closest distance from playback speaker, and vocal response. Of individual song phrases, the trill evoked the strongest response, and the whistle evoked the weakest. Combining these results with those of previous studies on young birds, we describe a model of developmental change from responsiveness to all phrase types in dependent fledglings, through reliance on a species-universal phrase as a cue for song learning, to the use of a more variable, dialect-distinct phrase as a territorial signal by adults. Respuestas de Adultos de Zonotrichia leucophrys al Playback de Cantos: Implicancias para la Ontogenia del Reconocimiento de Cantos Resumen. Examinamos la contribución de frases individuales de canto al comportamiento territorial de Zonotrichia leucophrys nuttalli en el área del dialecto de Bodega, California. Enfrentamos a machos adultos territoriales con playbacks de cinco tipos de canto: canto local de aves coespecíficas, tres tipos de frases individuales de canto local de aves coespecíficas, y canto de Melospiza melodia. El canto local de aves coespecíficas produjo la respuesta más fuerte, medida como latencia a volar, número de vuelos, distancia media y mínima a la estación de playback, y respuesta vocal. De las frases individuales de canto, el trino produjo la respuesta más fuerte y el silbido la más débil. Combinando estos resultados con aquellos de estudios anteriores en aves jóvenes, describimos un modelo de cambio en las etapas del desarrollo del canto que va desde la respuesta a todos los tipos de frases en volantones dependientes, pasando por una etapa de dependencia de una frase común a todas las especies como guía para aprender cantos, hasta el uso de una frase dialéctica distintiva como señal territorial en los adultos.


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