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Terms modified by Playback Selected AbstractsStrophe Length in Spontaneous Songs Predicts Male Response to Playback in the Hoopoe Upupa epopsETHOLOGY, Issue 5 2004Manuel Martín-Vivaldi Hoopoe (Upupa epops, Coraciformes) males produce a very simple song during the breeding season in order to attract females and repel intruders. Strophes vary in length (i.e. number of elements) both within and between males, and previous studies have shown that this song cue is positively correlated with male condition and breeding success. In the present study we tested whether strophe length of males influences male behaviour during intra-sexual contests, in a colour-ringed population in southeast Spain. Paired males were presented with a recorded song with long strophes during the pre-laying period, while they were near their mates, in order to provoke male mate-defence behaviour. Most males responded to the playback, but the strategy of defence adopted depended on their own strophe length in spontaneous songs recorded before the experiments. While singing responses were common to most of the males, only those using long strophes adopted the most risky strategy of approaching the loudspeaker. However, the males that approached produced abnormal songs during playback, that were shorter and with fewer strophes than those of males that did not approach, and used shorter strophes in comparison with spontaneous songs before the experiment. These differences in quality of the song produced in response to the playback suggest that long-strophe males were basing their response mainly on attacking rather than singing, while short-strophe males tried to resolve the contest at a distance by means of their song. These results show that strophe length reflects some component of the competitive ability of males (either physical strength or aggressiveness) in the hoopoe, which together with previous results regarding its role for female choice, show that it is a sexual signal with dual function. [source] A review of acoustic playback techniques for studying avian vocal duetsJOURNAL OF FIELD ORNITHOLOGY, Issue 2 2010Sarah B. Douglas ABSTRACT Playback experiments involve the broadcast of natural or synthetic sound stimuli and provide a powerful tool for studying acoustic communication in birds. Playback is a valuable technique for exploring vocal duetting behavior because it allows investigators to test predictions of the various hypotheses for duet function. Here, we adopt a methodological perspective by considering various challenges specific to studying duetting behavior, and highlighting the utility of different playback designs for testing duet function. Single-speaker playback experiments allow investigators to determine how duetting birds react to different stimuli, but do not simulate duets in a spatially realistic manner. Multi-speaker playback experiments are superior to single-speaker designs because duet stimuli are broadcast with spatial realism and unique and additional predictions can be generated for testing duet function. In particular, multi-speaker playback allows investigators to evaluate how birds respond to male versus female duet contributions separately, based on reactions to the different loudspeakers. Interactive playback allows investigators to ask questions about the time- and pattern-specific singing behavior of birds, and to understand how singing strategies correspond to physical behavior during vocal interactions. Although logistically challenging, interactive playback provides a powerful tool for examining specific elements of duets (such as the degree of coordination) and may permit greater insight into their functions from an operational perspective. Interactive playback designs where the investigator simulates half of a duet may be used to describe and investigate the function of pair-specific and population-wide duet codes. Regardless of experimental design, all playback experiments should be based on a sound understanding of the natural duetting behavior of the species of interest, and should aim to produce realistic and carefully controlled duet simulations. Future studies that couple playback techniques with other experimental procedures, such as Acoustic Location System recordings for monitoring the position of birds in dense vegetation or multimodal techniques that combine acoustic with visual stimuli, are expected to provide an even better understanding of these highly complex vocal displays. RESUMEN Los experimentos de reproducción de sonidos grabados involucran el uso de sonido natural o sintético y proveen una herramienta poderosa para el estudio de la comunicación acústica de las aves. La reproducción de sonidos grabados es una técnica valiosa para explorar las duetas vocales porque permite probar las predicciones de varios hipótesis sobre la función de duetas. Aquí, adoptamos una perspectiva metodológica, considerando los varios retos específicos al estudio del comportamiento de duetas y resaltando la utilidad de diferentes diseños de reproducción de sonidos grabados para probar la función de las duetas. Experimentos de reproducción de sonidos grabados hechas con un parlante permiten una determinación de como las aves que realizan duetas reaccionan a diferentes estímulos, pero no simulan las duetas de una manera espacialmente realística. Experimentos de reproducción de sonidos grabados hechas con múltiples parlantes son superiores a diseños con un solo parlante porque transmiten el sonido de una manera espacialmente realística y generan predicciones únicas y adicionales para probar la función de la dueta. En particular, la reproducción de sonidos grabados con múltiples parlantes permite una evaluación de cómo las aves responden a las contribuciones del macho y de la hembra separadamente, basado en sus reacciones a los diferentes parlantes. La reproducción de sonidos grabados interactiva permite hacer preguntas temporalmente especificas y en relación a patrones especificas sobre el comportamiento de canto. También permite entender como las estrategias de canto corresponden al comportamiento físico durante las interacciones vocales. Aunque es un reto logístico, la reproducción de sonidos grabados interactiva provee una herramienta poderosa para examinar elementos específicos de las duetas (como el grado de coordinación) y podría permitir un mayor conocimiento sobre sus funciones de una perspectiva operacional. Los diseños de la reproducción de sonidos grabados interactivas, en la cual el investigador simula la mitad de una dueta, podrían ser usadas para describir e investigar la función de los códigos de dueta específicos a una pareja y a una población. Sin importar el tipo de diseño experimental, todos los experimentos de reproducción de sonidos grabados deberían ser basadas en una buena comprensión del comportamiento natural de las duetas en la especie de interés, y deberían tener la meta de producir simulaciones de duetas realísticas y cuidadosamente controladas. Se espera que los estudios futuros cuales combinan técnicas de la reproducción de sonidos grabados con otros procedimientos experimentales, como grabaciones del Sistema de Ubicación Acústica para monitorear la posición de aves en vegetación densa, o técnicas multimodales que combinan estímulos acústicos con estímulos visuales, provean un mejor entendimiento de estos despliegues vocales altamente complejos. [source] Responses of Redfronted Lemurs to Experimentally Modified Alarm Calls: Evidence for Urgency-Based Changes in Call StructureETHOLOGY, Issue 9 2002Claudia Fichtel Alarm calls can serve as model systems with which to study this general question. Therefore, we examined the information content of terrestrial predator alarm calls of redfronted lemurs (Eulemur fulvus rufus), group-living Malagasy primates. Redfronted lemurs give specific alarm calls only towards raptors, whereas calls given in response to terrestrial predators (woofs) are also used in other situations characterized by high arousal. Woofs may therefore have the potential to express the perceived risk of a given threat. In order to examine whether different levels of arousal are expressed in call structure, we analysed woofs given during inter-group encounters or in response to playbacks of a barking dog, assuming that animals engaged in inter-group encounters experience higher arousal than during the playbacks of dog barks. A multivariate acoustic analysis revealed that calls given during group encounters were characterized by higher frequencies than calls given in response to playbacks of dog barks. In order to examine whether this change in call structure is salient to conspecifics, we conducted playback experiments with woofs, modified in either amplitude or frequencies. Playbacks of calls with increased frequency or amplitude elicited a longer orienting response, suggesting that different levels of arousal are expressed in call structure and provide meaningful information for listeners. In conclusion, the results of our study indicate that the information about the sender's affective state is expressed in the structure of vocalizations. [source] Pair Duets in the Yellow-Naped Amazon (Psittaciformes: Amazona auropalliata): Responses to Playbacks of Different DialectsETHOLOGY, Issue 2 2001Timothy F. Wright Yellow-naped amazons, Amazona auropalliata, have regional dialects in which several functional classes of vocalization, including contact calls and pair duets, change their acoustic structure at the same geographic boundaries. Here we examine the responses of 11 pairs of yellow-naped amazons to playbacks of duets from other pairs nesting near the same roost, other roosts within the same dialect, and roosts in foreign dialect areas. Overall, pairs responded more strongly to duets from their own dialect than to those of the foreign dialect. Pairs responded to both treatments from their own dialect (local same dialect and distant same dialect) with movement towards the broadcasting loudspeaker and more rarely with squeals, a vocalization typically observed only in the context of aggressive chases. These aggressive responses were never observed during playbacks of the foreign dialect treatment or congeneric controls. There were no differences among treatments in the incidence of contact calls or pair duets. A similar pattern of stronger aggressive responses to local than to foreign dialects has been found in a wide range of oscine songbirds. The results of the present experiment suggest that a general function may underlie this behavioral response both in oscines and in other bird taxa with vocal learning. [source] The double vocal signature of crested penguins: is the identity coding system of rockhopper penguins Eudyptes chrysocome due to phylogeny or ecology?JOURNAL OF AVIAN BIOLOGY, Issue 5 2005Amanda Searby Parent-offspring recognition systems are used in bird colonies to avoid misdirected parental care. In penguins, where the risk of confusion is particularly high, recognition is achieved by acoustic signals that constitute highly efficient vocal signatures. Comparisons between species from the Pygoscelis and Aptenodytes genera have revealed interspecific differences on the encoding of information within the signatures which correlate with the presence/absence of nests in the colonies. However a recent study of individual recognition in macaroni penguins Eudyptes chrysolophus revealed diversity within nest-building species. This paper investigates whether the original and intermediate signature system found in macaroni penguins is shared by another species of Eudyptes, the rockhopper penguin E. chrysocome. Vocal signatures of rockhopper penguins were analysed and compared to macaroni penguins'. We used a methodology derived from the theory of information to determine which parameters of the call were likely to encode individual identity. Playbacks of modified calls in the field complemented the analyses, and parent-chick reunions were compared between the two species. Our results reveal a similar double signature system within the Eudyptes genus, which integrates information simultaneously from the temporal and spectral domains. This double encoding is made through the tempo given by the successive syllables of the call and the harmonic content of the call. While it confirms the hypothesis that signatures are simpler in nest-building species, this result reveals differences in the efficacies of signatures within this category. This suggests that other parameters such as the mean distance recognition should be considered to account for the differences in the encoding of the vocal signatures and in their resulting efficacies. [source] The development of stimulus-specific auditory responses requires song exposure in male but not female zebra finchesDEVELOPMENTAL NEUROBIOLOGY, Issue 1 2010Kristen K. Maul Abstract Juvenile male zebra finches develop their song by imitation. Females do not sing but are attracted to males' songs. With functional magnetic resonance imaging and event-related potentials we tested how early auditory experience shapes responses in the auditory forebrain of the adult bird. Adult male birds kept in isolation over the sensitive period for song learning showed no consistency in auditory responses to conspecific songs, calls, and syllables. Thirty seconds of song playback each day over development, which is sufficient to induce song imitation, was also sufficient to shape stimulus-specific responses. Strikingly, adult females kept in isolation over development showed responses similar to those of males that were exposed to songs. We suggest that early auditory experience with songs may be required to tune perception toward conspecific songs in males, whereas in females song selectivity develops even without prior exposure to song. © 2009 Wiley Periodicals, Inc. Develop Neurobiol 2010 [source] Immediate early gene (ZENK, Arc) expression in the auditory forebrain of female canaries varies in response to male song qualityDEVELOPMENTAL NEUROBIOLOGY, Issue 3 2005Stefan Leitner Abstract In male songbirds, the song control pathway in the forebrain is responsible for song production and learning, and in females it is associated with the perception and discrimination of male song. However, experiments using the expression of immediate early genes (IEGs) reveal the activation of brain regions outside the song control system, in particular the caudomedial nidopallium (NCM) and the caudomedial mesopallium (CMM). In this study on female canaries, we investigate the role of these two regions in relation to playback of male songs of different quality. Male canaries produce elaborate songs and some contain syllables with a more complex structure (sexy syllables) that induce females to perform copulation solicitation displays (CSD) as an invitation to mate. Females were first exposed to playback of a range of songs of different quality, before they were finally tested with playback of songs containing either sexy or nonsexy syllables. We then sectioned the brains and used in situ hybridization to reveal brain regions that express the IEGs ZENK or Arc. In CMM, expression of ZENK mRNA was significantly higher in females that last heard sexy syllables compared to those that last heard nonsexy syllables, but this was not the case for NCM. Expression of Arc mRNA revealed no differences in either CMM or NCM in both experimental groups. These results provide evidence that in female canaries CMM is involved in female perception and discrimination of male song quality through a mechanism of memory reconsolidation. The results also have further implications for the evolution of complex songs by sexual selection and female choice. © 2005 Wiley Periodicals, Inc. J Neurobiol, 2005 [source] Female canaries that respond and discriminate more between male songs of different quality have a larger song control nucleus (HVC) in the brainDEVELOPMENTAL NEUROBIOLOGY, Issue 4 2002Stefan Leitner Abstract In male songbirds the song control pathway in the forebrain is responsible for song production and learning. In most species, females do not sing and have smaller nuclei in the song control pathway. Although the function of the pathway in females is assumed to be associated with the perception of male song, there is little direct evidence to support this view. In this study on female canaries, we investigate the role of two key nuclei in the song control pathway (HVC and lMAN) in relation to playback of male song. Male canaries produce elaborate songs that function to attract and stimulate females. The songs are constructed from smaller units called syllables, and special syllables with a more complex structure (sexy syllables) are known to induce females to perform copulation solicitation displays (CSD) as an invitation to mate. By using computer-edited experimental songs, we first show that females discriminate between songs by producing significantly more CSD to those containing sexy syllables. We then sectioned the brains and used in situ hybridization to reveal song nuclei containing androgen receptors. We report positive correlations between the size of HVC and both total CSD response and the amount of discrimination between sexy and nonsexy songs. We found no such relationships between these measures and the size of lMAN. These results provide some evidence to support the view that, in female canaries HVC is involved in female perception and discrimination of male song. The results also have implications for the evolution of complex male songs by sexual selection and female choice. © 2002 Wiley Periodicals, Inc. J Neurobiol 52: 294,301, 2002 [source] Eavesdropping on the Neighbourhood: Collared Pika (Ochotona collaris) Responses to Playback Calls of Conspecifics and HeterospecificsETHOLOGY, Issue 10 2009Sarah A. Trefry The acoustic environment, composed in part by the vocalizations of sympatric animals, is a major source of information and can be used to fine-tune behavioural decisions. Active assessment of alarm calls within and between mammal species is not fully understood. We explored the behavioural responses of collared pikas to con- and heterospecific vocalizations, in order to determine whether they selectively attend to these calls. Pikas increased their vigilance after playback of alarm calls of heterospecific mammals (marmots and ground squirrels), but responded most strongly to conspecific calls. While responses to playback calls of their own, of neighbours and of a stranger did not differ, pikas did discriminate between individual callers in a habituation-discrimination experiment. The ability to make use of information from different sources in their acoustic environment likely facilitates pikas' behavioural decisions that affect foraging, predator avoidance and nepotism. [source] The Effect of Hemosporidian Infections on White-Crowned Sparrow Singing BehaviorETHOLOGY, Issue 5 2007Sarah Gilman Relatively little is known about the effects of specific parasites on sexually selected behavioral traits. We subjected free-living mountain white-crowned sparrows (Zonotrichia leucophrys oriantha) to a playback experiment to identify the effect of hemosporidian parasites on potentially sexually selected song characteristics. We recorded song after a playback of a novel white-crowned sparrow song, meant to simulate a territorial intrusion. Infections with Leucocytozoon or Plasmodium influenced singing behavior, while infection with Haemoproteus had no detectable effect. Specifically, song consistency, as measured using a spectrogram correlation, was influenced by both Plasmodium and Leucocytozoon infection. Additionally, birds infected with Plasmodium sang fewer songs following experimental playback. Thus, relatively widespread parasites, like Plasmodium, may have a strong effect on potentially sexually selected song characteristics. [source] The Mechanics of Duetting in a New Zealand Endemic, the Kokako (Callaeas cinerea wilsoni): Song at a Snail's PaceETHOLOGY, Issue 5 2006Laura E. Molles New Zealand's endemic, duetting kokako (Callaeas cinerea wilsoni) produce one of the longest known bird songs (ca 30 s) and duets that differ strikingly from those of most duetters in their unusual length and non-repetitive structure, long pauses between component phrases, and the great flexibility in sex roles. Here we present a structural analysis of the vocalizations of 17 kokako pairs collected during natural song bouts and in response to conspecific playback, to gain insight into the functional role of this extraordinary vocal behavior. Males tend to sing a greater proportion of the duet than females. Like many duetting species, kokako have a moderately sized repertoire of phrases (mean repertoire size =18) and pair members tend to sing antiphonally rather than in unison. Sharing of phrase types is high among neighboring kokako ( = 86%) and repertoires are not sex specific, as is typical of some but not all duetting species. Timing characteristics, broad sharing of phrase types, and countersinging behavior strongly suggest that kokako duets play an important role in territory defense. Additionally, differences in pairs' sex role and phrase sequence flexibility suggest that these aspects of duet performance may reflect pair-bond length or commitment, and require a time investment by pair members. [source] Strophe Length in Spontaneous Songs Predicts Male Response to Playback in the Hoopoe Upupa epopsETHOLOGY, Issue 5 2004Manuel Martín-Vivaldi Hoopoe (Upupa epops, Coraciformes) males produce a very simple song during the breeding season in order to attract females and repel intruders. Strophes vary in length (i.e. number of elements) both within and between males, and previous studies have shown that this song cue is positively correlated with male condition and breeding success. In the present study we tested whether strophe length of males influences male behaviour during intra-sexual contests, in a colour-ringed population in southeast Spain. Paired males were presented with a recorded song with long strophes during the pre-laying period, while they were near their mates, in order to provoke male mate-defence behaviour. Most males responded to the playback, but the strategy of defence adopted depended on their own strophe length in spontaneous songs recorded before the experiments. While singing responses were common to most of the males, only those using long strophes adopted the most risky strategy of approaching the loudspeaker. However, the males that approached produced abnormal songs during playback, that were shorter and with fewer strophes than those of males that did not approach, and used shorter strophes in comparison with spontaneous songs before the experiment. These differences in quality of the song produced in response to the playback suggest that long-strophe males were basing their response mainly on attacking rather than singing, while short-strophe males tried to resolve the contest at a distance by means of their song. These results show that strophe length reflects some component of the competitive ability of males (either physical strength or aggressiveness) in the hoopoe, which together with previous results regarding its role for female choice, show that it is a sexual signal with dual function. [source] Phonology and Geographic Song Discrimination in Song SparrowsETHOLOGY, Issue 1 2003William A. Searcy We investigated whether song sparrows discriminate foreign from local songs using specific phonologic markers, a mechanism of geographic discrimination previously described for some other songbirds. Song sparrows from Linesville, Pennsylvania (PA) respond more strongly to local songs than to songs from Millbrook, New York (NY). We identify 61 note categories in PA and NY songs, of which 13 are unique to PA, 17 are unique to NY, and 31 are shared. The most common note category in PA song, ,buzz BO5', is present in 89% of PA songs and only in 8% of NY songs; this difference in percentage representation is the largest we found for any note category. Substituting this potential PA marker into NY songs, however, did not make those songs more salient to PA sparrows; instead, PA males tested with territorial playback responded significantly less aggressively to NY/PA hybrid songs than to NY songs. A series of control experiments showed that song sparrows do not detect substitution of PA notes into PA songs or of NY notes into NY songs. The results weigh against the hypothesis that geographic discrimination in song sparrows is accomplished simply by recognition of a small number of phonologic markers. [source] Dynamic bandwidth allocation and buffer dimensioning under equal segment scheme to support video-on-demand servicesINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 10 2001Liren Zhang Abstract This paper focuses on the optimization of network bandwidth allocation and buffer dimensioning to transport pre-stored MPEG video data from source to playback destination across ATM networks. This is one of the most important issues in the support of video-on-demand (VoD) service. This paper provides a novel scheme in the dynamic allocation of bandwidth to segments of video using ABR mode. The dynamic bandwidth allocation is based on a new concept, called playback tunnel which is obtained from the traffic characteristics of the pre-stored MPEG video trace to determine the optimum of transmission bandwidth as well as the buffer capacity to ensure that the playback buffer neither underflows nor overflows. The proposed scheme is tested with real-life MPEG video traces. The obtained results have shown its significant performance improvement in terms of the capacity of playback buffer, the start-up playback delay, the size of video segment and the network multiplexing gain. Copyright © 2001 John Wiley & Sons, Ltd. [source] Roosting behavior of a Neotropical migrant songbird, the northern waterthrush Seiurus noveboracensis, during the non-breeding seasonJOURNAL OF AVIAN BIOLOGY, Issue 4 2008Joseph A. M. Smith Several species of Nearctic-Neotropical migratory songbirds appear to form roosting aggregations while on their wintering grounds but little is understood about the ecology of this behavior. We studied roosting behavior and patterns of roost habitat selection in the northern waterthrush Seiurus noveboracensis, during three winter years (2002,2004) in Puerto Rico using radio telemetry. Overall, red mangrove was selected for roosting disproportionately to its availability. Regardless of diurnal habitat used, 87% (n=86) of northern waterthrush selected dense stands of coastal red mangrove for roost sites. Individuals traveled up to 2 km to access roost sites in this habitat on a daily basis. The majority (8 of 14) of individuals roosted alone, while others roosted in loose aggregations near communal roosts of gray kingbirds Tyrannus dominicensis. Patterns of roost site selection did not vary by sex. Individuals showing aggressive response to playback during the day, however, selected roost sites significantly closer to the coast. Several additional migratory and resident bird species also used red mangrove for night-time roosting habitat. Red mangrove may be a critical nocturnal roosting habitat for bird populations that live in proximity to coastal areas in the Neotropics. The benefits of nocturnal roosting behavior as well as why individuals appear to select red mangrove remain poorly understood. [source] Cautious response of inexperienced birds to conventional signal of stronger threatJOURNAL OF AVIAN BIOLOGY, Issue 6 2007Tomasz S. Osiejuk Several studies demonstrated that bird song functions as a first line of territorial defence. The efficiency of deterring rivals depends strongly on the strategy of singing used (e.g. alternating/overlapping singing, singing with low/high rate, matching song type of a rival or singing different type). Causes of between males variation during countersinging are still not fully understood, especially when different signals have similar production costs and their meaning is assigned by arbitrary convention (conventional signalling). We tested whether an oscine bird with small repertoire size, the ortolan bunting Emberiza hortulana, differentiate strategy of responding to song of an intruder in relation to its age and threat value of signals. We performed playback experiments to measure response of second year (SY) and after second year (ASY) males to a song of low (eventual variety singing) and high (immediate variety singing) threat value. We found substantial differences in response to playback, which were related both to the type of stimuli used and age of responding males. Both SY and ASY males gave more calls than songs in response to immediate variety playback, which suggest stronger vocal response to the signal of higher threat value. Approaching loudspeaker was similar for both age classes when lower threat value signal was played back, while simultaneously SY males clearly avoided approaching loudspeaker when stronger threat values signal was played back. We conclude that ortolan bunting differentiate response to signal of different threat value and that the strength of response depends on the age of a male. This study provides experimental evidence that age of receiver affects its response to a territorial intruder. It also demonstrates that observed in many studies variation in response to playback may be an effect of age differences between males, which rarely is controlled. [source] Neighbour-stranger song discrimination in territorial ortolan bunting Emberiza hortulana malesJOURNAL OF AVIAN BIOLOGY, Issue 4 2007Micha, Skierczynski Neighbour-stranger discrimination has been demonstrated in many species, but the mechanisms employed in discrimination vary. We tested whether an oscine bird with small repertoire size, the ortolan bunting Emberiza hortulana, discriminated between songs of neighbours and strangers. We performed playback experiments to measure response of males to a repeated single example of a single song type derived from a repertoire of a neighbour or stranger. Thirteen males were tested twice each, and in both cases songs were broadcast from the territory boundary shared by the subject male and the neighbour. Subjects responded more aggressively to songs of strangers than neighbours, i.e. they approached the loudspeaker faster and came closer and did more flights during the playback of stranger song. We found no significant differences in vocal response between treatments. We conclude that ortolan bunting can discriminate between songs of neighbours and strangers. This study provides experimental evidence for ortolan buntings in neighbour-stranger discrimination. It also demonstrates that a single example of song is enough to discriminate between neighbours and strangers. We discuss which song characteristics are the possible acoustic basis for discrimination in the studied species. [source] Acoustic properties of male advertisement and their impact on female responsiveness in little penguins Eudyptula minorJOURNAL OF AVIAN BIOLOGY, Issue 3 2003Masamine Miyazaki We examined the relationship between acoustic properties of male advertising calls, male body size and female responses in little penguins Eudyptula minor. Larger males produced calls of lower frequency. Playback experiments indicated that females were more likely to respond to low or medium pitched calls, than to high ones (although only 28% of females responded vocally to playback). This may reflect the interest of unmated females in large to medium sized senders as potential mates, or indicate a stronger territorial response to large intruders. [source] Song perception among incipient species as a mechanism for reproductive isolationJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 3 2008M. BRAMBILLA Abstract Many functions in behavioural processes of small passerines are regulated via vocal messages. Song plays an important role in the development of reproductive barriers and thus playback experiments can often be used for investigating the potential for reproductive isolation through behavioural mechanisms. Moltoni's warbler Sylvia (cantillans) moltonii is characterized by diagnostic vocalizations and a peculiar pattern of distribution, being parapatric and partly sympatric with the nominate Sylvia c. cantillans. With this work, we test whether these two closely related taxa react equally to their own song and to the song of the other taxon, shedding light on whether they perceive each other's songs as coming from the same species. We carried out 184 playback experiments within the mainland range of the two forms. We judged the response of the bird on a scale of scores. Each taxon responded more strongly to playback when faced with the song of its own taxon. This held true when applied only to males or females. Additionally, birds tested for both songs showed a stronger response to the song of their own taxon. The distributional context (sympatry vs. allopatry) did not affect bird response. Results indicate that a certain degree of reproductive isolation between the two taxa (because of diverged mate recognition systems) already exists; consistently with genetic data and with the peculiar pattern of distribution; this suggests that the two taxa have reached species status. [source] Reconstructing asymmetrical reproductive character displacement in a periodical cicada contact zoneJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 3 2006JOHN R. COOLEY Abstract Selection against costly reproductive interactions can lead to reproductive character displacement (RCD). We use information from patterns of displacement and inferences about predisplacement character states to investigate causes of RCD in periodical cicadas. The 13-year periodical cicada Magicicada neotredecim exhibits RCD and strong reproductive isolation in sympatry with a closely related 13-year species, Magicicada tredecim. Displacement is asymmetrical, because no corresponding pattern of character displacement exists within M. tredecim. Results from playback and hybridization experiments strongly suggest that sexual interactions between members of these species were possible at initial contact. Given these patterns, we evaluate potential sources of selection for displacement. One possible source is ,acoustical interference', or mate-location inefficiencies caused by the presence of heterospecifics. Acoustical interference combined with the species-specificity of song pitch and preference appears to predict the observed asymmetrical pattern of RCD in Magicicada. However, acoustical interference does not appear to be a complete explanation for displacement in Magicicada, because our experiments suggest a significant potential for direct sexual interactions between these species before displacement. Another possible source of selection for displacement is hybrid failure. We evaluate the attractiveness of inferred hybrid mating signals, and we examine the viability of hybrid eggs. Neither of these shows strong evidence of hybrid inferiority. We conclude by presenting a model of hybrid failure related to life cycle differences in Magicicada. [source] A review of acoustic playback techniques for studying avian vocal duetsJOURNAL OF FIELD ORNITHOLOGY, Issue 2 2010Sarah B. Douglas ABSTRACT Playback experiments involve the broadcast of natural or synthetic sound stimuli and provide a powerful tool for studying acoustic communication in birds. Playback is a valuable technique for exploring vocal duetting behavior because it allows investigators to test predictions of the various hypotheses for duet function. Here, we adopt a methodological perspective by considering various challenges specific to studying duetting behavior, and highlighting the utility of different playback designs for testing duet function. Single-speaker playback experiments allow investigators to determine how duetting birds react to different stimuli, but do not simulate duets in a spatially realistic manner. Multi-speaker playback experiments are superior to single-speaker designs because duet stimuli are broadcast with spatial realism and unique and additional predictions can be generated for testing duet function. In particular, multi-speaker playback allows investigators to evaluate how birds respond to male versus female duet contributions separately, based on reactions to the different loudspeakers. Interactive playback allows investigators to ask questions about the time- and pattern-specific singing behavior of birds, and to understand how singing strategies correspond to physical behavior during vocal interactions. Although logistically challenging, interactive playback provides a powerful tool for examining specific elements of duets (such as the degree of coordination) and may permit greater insight into their functions from an operational perspective. Interactive playback designs where the investigator simulates half of a duet may be used to describe and investigate the function of pair-specific and population-wide duet codes. Regardless of experimental design, all playback experiments should be based on a sound understanding of the natural duetting behavior of the species of interest, and should aim to produce realistic and carefully controlled duet simulations. Future studies that couple playback techniques with other experimental procedures, such as Acoustic Location System recordings for monitoring the position of birds in dense vegetation or multimodal techniques that combine acoustic with visual stimuli, are expected to provide an even better understanding of these highly complex vocal displays. RESUMEN Los experimentos de reproducción de sonidos grabados involucran el uso de sonido natural o sintético y proveen una herramienta poderosa para el estudio de la comunicación acústica de las aves. La reproducción de sonidos grabados es una técnica valiosa para explorar las duetas vocales porque permite probar las predicciones de varios hipótesis sobre la función de duetas. Aquí, adoptamos una perspectiva metodológica, considerando los varios retos específicos al estudio del comportamiento de duetas y resaltando la utilidad de diferentes diseños de reproducción de sonidos grabados para probar la función de las duetas. Experimentos de reproducción de sonidos grabados hechas con un parlante permiten una determinación de como las aves que realizan duetas reaccionan a diferentes estímulos, pero no simulan las duetas de una manera espacialmente realística. Experimentos de reproducción de sonidos grabados hechas con múltiples parlantes son superiores a diseños con un solo parlante porque transmiten el sonido de una manera espacialmente realística y generan predicciones únicas y adicionales para probar la función de la dueta. En particular, la reproducción de sonidos grabados con múltiples parlantes permite una evaluación de cómo las aves responden a las contribuciones del macho y de la hembra separadamente, basado en sus reacciones a los diferentes parlantes. La reproducción de sonidos grabados interactiva permite hacer preguntas temporalmente especificas y en relación a patrones especificas sobre el comportamiento de canto. También permite entender como las estrategias de canto corresponden al comportamiento físico durante las interacciones vocales. Aunque es un reto logístico, la reproducción de sonidos grabados interactiva provee una herramienta poderosa para examinar elementos específicos de las duetas (como el grado de coordinación) y podría permitir un mayor conocimiento sobre sus funciones de una perspectiva operacional. Los diseños de la reproducción de sonidos grabados interactivas, en la cual el investigador simula la mitad de una dueta, podrían ser usadas para describir e investigar la función de los códigos de dueta específicos a una pareja y a una población. Sin importar el tipo de diseño experimental, todos los experimentos de reproducción de sonidos grabados deberían ser basadas en una buena comprensión del comportamiento natural de las duetas en la especie de interés, y deberían tener la meta de producir simulaciones de duetas realísticas y cuidadosamente controladas. Se espera que los estudios futuros cuales combinan técnicas de la reproducción de sonidos grabados con otros procedimientos experimentales, como grabaciones del Sistema de Ubicación Acústica para monitorear la posición de aves en vegetación densa, o técnicas multimodales que combinan estímulos acústicos con estímulos visuales, provean un mejor entendimiento de estos despliegues vocales altamente complejos. [source] Determining woodpecker diversity in the sub-Himalayan forests of northern India using call playbacksJOURNAL OF FIELD ORNITHOLOGY, Issue 2 2010Raman Kumar ABSTRACT Tropical forests have exceptional woodpecker diversity, but little is known about the abundance and diversity of woodpeckers in the Indian subcontinent, particularly for the Shorea robusta -dominated moist deciduous forests of northern India. Our objective was to compare the number of woodpecker species and number of individuals detected using playback surveys and visual/aural transect surveys at five sites. Each site was surveyed 5,6 times along a 2000-m transect, with woodpeckers detected using two methods: (1) visual and aural cues, and (2) playing back calls of 13 species at 400-m intervals. Both methods involved similar effort per survey (100,110 min). During surveys, we detected 11 species of woodpeckers. More species and more than twice as many individuals were detected during playback surveys than during visual/aural surveys. In addition, species accumulation curves showed that we detected the species known to be present based on previous work faster with playback surveys than with visual/aural surveys at four of the five sites. During field trials, 97% of targeted individuals (N= 269) of 12 species responded to playback, and 83% of the responses occurred within 1 min of broadcast. The number of species of woodpeckers in our study area (11 species) was typical for a structurally diverse, tropical/subtropical moist broad-leaved forest. Our results demonstrate that playback surveys are more efficient and accurate than visual/aural surveys, and that playback surveys can be useful for assessing and monitoring woodpecker diversity in tropical forests. RESUMEN Los bosques tropicales tienen una diversidad excepcional de pájaros carpinteros, pero se conoce muy poco sobre la abundancia y diversidad de estas aves en la parte norte del sub-continente de la India, particularmente en el bosque deciduo húmedo dominado por Shorea robusta. Nuestro objetivo fue comparar el número de especies y de individuos de carpinteros utilizando grabaciones para censarlos y transectos visuales/auditivos en cinco lugares. Cada lugar fue censado 5,6 veces, cada 400m, a lo largo de un transecto de 2000 m, utilizando pistas visuales y auditivas y grabaciones de 13 especies. Ambos métodos incluyeron un esfuerzo similar por censo (100,110 minutos). Durante los censos, detectamos 11 especies de pájaros carpinteros. Una cantidad mayor de especies y más del doble de los individuos fueron detectados utilizando grabaciones que en los censos visuales/auditivos. Además, las curvas de acumulación de especies mostraron que detectamos las especies que sabíamos estaban presentes (basados en trabajos previos) de forma más rápida utilizando grabaciones que con el método visual/auditivo en cuatro de las cinco localidades. Durante las pruebas de campo el 97% (N= 269) de 12 especies respondieron a las grabaciones, y el 83% de las respuestas se obtuvieron un minuto después de exponerlos a la grabación. El número de especies de pájaros carpinteros en nuestra área de estudio (11) fue el típico para un bosque tropical/subtropical húmedo de hoja ancha y estructura diversificada. Nuestros resultados demuestran que los censos en donde se usan grabaciones son más eficientes y precisos que los censos visuales/auditivos. Además que los censos en donde se usan grabaciones pueden ser útiles para determinar y monitorear la diversidad de carpinteros en bosques tropicales. [source] Nests, vocalizations, and conservation status of endangered Cochabamba Mountain-Finches (Compsospiza garleppi)JOURNAL OF FIELD ORNITHOLOGY, Issue 3 2009Noemí Esther Huanca ABSTRACT Cochabamba Mountain-Finches (Compsospiza garleppi) are endangered residents of semihumid shrublands in the high Andes, with a range restricted to a few high valleys surrounding the city of Cochabamba, Bolivia. We examined the breeding behavior, feeding ecology, habitat requirements, vocalizations, and conservation status of Cochabamba Mountain-Finches from November 2006 to April 2007. We observed 10 nests of eight pairs, with nests found in a variety of small woody shrubs as well as bunchgrass and a ground bromeliad. Clutches (N= 2) consisted of one or two eggs, and all broods (N= 4) included one or two young. Our observations suggest that Cochabamba Mountain-Finches are not Polylepis specialists as previously thought, and use a diversity of native shrubs often associated with Polylepis woodlands for foraging and nesting. Pairs inhabited modified habitats where native vegetation and woodland edge persisted, but were not observed in closed canopy woodlands. Cochabamba Mountain-Finches frequently foraged on the edges of potato fields in a rural community and, at least occasionally, consumed parts of unearthed tubers. We recorded two previously unknown song types and three types of calls, and one song type was found to be useful for playback surveys. We recommend that future research and conservation actions include thorough surveys using playback to determine population sizes, and that habitat restoration projects focus on maintaining a diversity of native shrubs rather than only Polylepis trees. SINOPSIS Compsospiza garleppi es una especie residente en peligro de las tierras arbustivas semihúmedas de los altos Andes, con un rango restringido a unos pocos valles en los alrededores de la ciudad de Cochabamba, Bolivia. Nosotros examinamos el comportamiento reproductivo, la ecología alimentaria, los requerimientos de hábitat, vocalizaciones y estado de conservación de Compsospiza garleppi desde Noviembre 2006 hasta Abril 2007. Observamos 10 nidos de ocho parejas, los nidos fueron encontrados en una variedad de pequeños arbustos al igual que en montones de pastos y bromelias de suelo. La nidadas (N= 2) consistieron de uno o dos huevos y uno o dos polluelos (N= 4). Nuestras observaciones sugieren que Compsospiza garleppi no es un especialista de Polylepis como se había pensado anteriormente, y usa una diversidad de arbustos nativos asociados con bosques de Polylepis para buscar alimento y anidar. Se encontraron parejas en hábitat modificado en donde la vegetación nativa y los bordes de bosque persistieron, pero no fueron observadas en bosques con un dosel cerrado. Compsospiza garlepp busco alimento frecuentemente en los bordes de plantaciones de papa en una comunidad rural y, ocasionalmente, consumió partes de tubérculos desenterrados. Nosotros grabamos dos cantos no descritos anteriormente y tres tipos de llamados, un tipo de los cantos fue beneficioso para estudios de playback. Nosotros recomendamos que futuros estudios y acciones de conservación usen playback como herramienta para realizar censos minuciosos para determinar tamaños poblacionales, y que proyectos de restauración de hábitat se enfoquen en el mantenimiento de la diversidad de arbustos nativos en vez de únicamente mantener árboles de Polylepis. [source] Similarity in the begging calls of nestling Red-winged BlackbirdsJOURNAL OF FIELD ORNITHOLOGY, Issue 3 2008Ken Yasukawa ABSTRACT Although individually distinct begging calls may permit parents to recognize their offspring, birds nesting in dense breeding colonies where fledglings intermingle might benefit from additional adaptations. For example, if the calls of all nestlings in a brood were similar, parents would need to recognize only one brood call instead of the identity calls of each nestling. We recorded nestling Red-winged Blackbirds (Agelaius phoeniceus) to determine whether their calls function to identify individuals (identity call hypothesis) or broods (brood call hypothesis). We used spectrogram cross-correlation and dynamic time warping as well as call duration, peak frequency, and frequency range to estimate the similarity of begging calls of nestling Red-winged Blackbirds. We recorded individual nestlings on day 5 and on day 9 of the nestling period to determine whether calls of individuals were more similar than calls of different nestlings, and whether calls of broodmates were more similar than calls of nestlings from different broods. We found that calls of 8-d-old individuals were more similar than calls of different nestlings, but the calls of broodmates were not more similar than those of nestlings from different broods. These results were consistent with the identity call hypothesis. We then compared begging calls of pairs of nestlings recorded separately and together on day 9. We found that the calls of 8-d-old nestlings recorded together were more similar than when they were recorded separately. In addition, using playback of begging calls from normal broods and artificial "broods" constructed from the calls of single nestlings, we found that females returned with food sooner in response to the calls of single nestlings (with enhanced call similarity) than to those of normal broods. Our results suggest that similar begging calls may be beneficial for both nestlings and parents, with broodmates fed at higher rates when their calls are more similar and, after fledging, parents needing to recognize only one brood call instead of the identity calls of each fledgling. SINOPSIS Aunque las diferencias individuales en los llamados de reclamo les pueden permitir a los padres reconocer a su progenie, aves que nidifican en grandes colonias de anidación donde los polluelos pueden mezclarse pueden obtener beneficios mediante adaptaciones adicionales. Por ejemplo, si los llamados de todos los polluelos en el nido son similares los padres necesitarian reconocer solo un tipo de reclamo de los polluelos en vez de identificar llamados individuales de los polluelos. Grabamos polluelos de Agelaius phoeniceus para determinar si sus llamados son usados para identificar individuos (Hipotesis de la identidad del polluelo) o para identificar a la progenie (Hipotesis de la identidad de la progenie). Usamos espectrogramas de correlación cruzada y dinamica del tiempo de combeo al igual que la duración del reclamo, el pico de frecuencia y frecuencia del rango para estimar la similaridad de los llamados de los polluelos de Agelaius phoeniceus. Grabamos polluelos individuales de 5 y 9 días de nacidos para determinar si los llamados de los individuos eran más similares a llamados de otros polluelos y si los llamados dentro de una progenie eran ma similares a llamados de otra progenie. Encontramos que los llamados de polluelos de 8 días de nacidos eran más similares que los llamados de diferentes polluelos, pero los polluelos de una misma progenie no fueron más similares que polluelos de diferentes progenies. Esto resultados concuerdan con la hipotesis de la identidad del polluelo. Después comparamos los llamados de parejas de polluelos grabados por separado y los que fueron grabados juntos el día 9. Encontramos que los llamados de polluelos de 8 días de nacidos grabados juntos fueron mas similares que cuando los polluelos fueron grabados por separado. Adicionalmente, usando playback de llamado de polluelos de progenies normales y progenies "artificales" construidos basado en llamado de un solo polluelo, encontramos que las hembras regresaron más rapidamente con alimento en respuesta al llamado de un solo polluelo (con realzamiento en la similaridad del llamado) que para las progenies normales. Nuestros resultados sugieren que la similaridad en los llamados de los reclamos pueden ser beneficiosos tanto para los polluelos como los padres, en donde las tasa de alimentación es mayor cuando sus llamados son mas similares, y después de abandonar el nido cuando los padres necesitan reconocer un solo llamado de la progenie en vez de tener que identificar llamados individuales de cada volanton. [source] CAD-based automated robot programming in adhesive spray systems for shoe outsoles and uppersJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 11 2004J. Y. Kim Most shoe manufacturing processes are not yet automated; it puts restrictions on increasing productivity. Among them, adhesive application processes particularly are holding the most workers and working hours. In addition, the working environment is very poor due to the toxicity of adhesive agents. In the case of automating an adhesive application process by using a robot, robot teaching by playback is difficult to produce high productivity because the kinds of shoes to be taught mount up to several thousands. To cope with it, it is necessary to generate robot working paths automatically according to the kind, the size, or the right and the left of shoes, and also to teach the generated paths to a robot automatically. This paper presents a method to generate three-dimensional robot working paths off-line based on CAD data in an automatic adhesive spray system for shoe outsoles and uppers. First, this paper describes how to extract the three-dimensional data of an outsole outline from a two-dimensional CAD drawing file. Second, it describes how to extract the three-dimensional data of an upper profiling line from the three-dimensional scanning data that is opened in a three-dimensional CAD program. Third, it describes how to generate robot working paths based on the extracted data and the nozzle setting parameters for adhesive spray. Also, a series of experiments for adhesive spray is performed to verify the effectiveness of the presented methods. This study will do much for increasing productivity in shoe manufacturing as a core work of a robotic adhesive spray system. © 2004 Wiley Periodicals, Inc. [source] Chewing-side determination of three food texturesJOURNAL OF ORAL REHABILITATION, Issue 1 2006J. PAPHANGKORAKIT summary, Food texture affects chewing movement but it is not known if it also affects the chewing-side pattern. This study determined the chewing sides of three test foods with different textures during habitual chewing. Twenty healthy dental students (aged 20,24 years) chewed pieces of pork jerky, fresh asparagus and almonds on two separate sessions (1 week apart). In each session, each subject chewed 30 food specimens, 10 of the same food type, until swallowing while a video camera recorded the displacement of the chin with respect to the other two reference points vertically marked along the facial midline. A slow-speed video playback was used to identify the chewing side of each cycle. The chewing-side pattern (right preference, left preference, no preference) in each individual was determined statistically. The results showed that overall, 11 subjects did not have any side preference whereas six and three subjects preferred to chew on right or left sides respectively. The chewing-side pattern remained unchanged between three food types in about half of the subjects. When the same food was compared between 2 days, the chewing-side pattern of almonds was shown to be most reproducible (18 subjects). Unidentified cycles with little or no lateral displacement, labelled as bilateral, were observed more frequently near the end of the chewing sequence with more occurrences in almonds and jerky than asparagus (P < 0·01). It was suggested that chewing-side preference is not a fixed characteristic. Food texture seemed to influence the side preference and also the occurrence of bilateral cycles. [source] Production and perception of sex differences in vocalizations of Wied's black-tufted-ear marmosets (Callithrix kuhlii)AMERICAN JOURNAL OF PRIMATOLOGY, Issue 4 2009Adam S. Smith Abstract Males and females from many species produce distinct acoustic variations of functionally identical call types. Social behavior may be primed by sex-specific variation in acoustic features of calls. We present a series of acoustic analyses and playback experiments as methods for investigating this subject. Acoustic parameters of phee calls produced by Wied's black-tufted-ear marmosets (Callithrix kuhlii) were analyzed for sex differences. Discriminant function analyses showed that calls contained sufficient acoustic variation to predict the sex of the caller. Several frequency variables differed significantly between the sexes. Natural and synthesized calls were presented to male,female pairs. Calls elicited differential behavioral responses based on the sex of the caller. Marmosets became significantly more vigilant following the playback of male phee calls (both natural and synthetic) than following female phee calls. In a second playback experiment, synthesized calls were modified by independently manipulating three parameters that were known to differ between the sexes (low-, peak-, and end-frequency). When end-frequency-modified calls were presented, responsiveness was differentiable by sex of caller but did not differ from responses to natural calls. This suggests that marmosets did not use end-frequency to determine the sex of the caller. Manipulation of peak-and low-frequency parameters eliminated the discrete behavioral responses to male and female calls. Together, these parameters may be important features that encode for the sex-specific signal. Recognition of sex by acoustic cues seems to be a multivariate process that depends on the congruency of acoustic features. Am. J. Primatol. 71:324,332, 2009. © 2008 Wiley-Liss, Inc. [source] Avoiding predators at night: antipredator strategies in red-tailed sportive lemurs (Lepilemur ruficaudatus)AMERICAN JOURNAL OF PRIMATOLOGY, Issue 6 2007Claudia Fichtel Abstract Although about one-third of all primate species are nocturnal, their antipredator behavior has rarely been studied directly. Crypsis and a solitary lifestyle have traditionally been considered to be the main adaptive antipredator strategies of nocturnal primates. However, a number of recent studies have revealed that nocturnal primates are not as cryptic and solitary as previously suggested. Thus, the antipredator strategies available for diurnal primates that rely on early detection and warning of approaching predators may also be available to nocturnal species. In order to shed additional light on the antipredator strategies of nocturnal primates, I studied pair-living red-tailed sportive lemurs (Lepilemur ruficaudatus) in Western Madagascar. In an experimental field study I exposed adult sportive lemurs that lived in pairs and had offspring to playbacks of vocalizations of their main aerial and terrestrial predators, as well as to their own mobbing calls (barks) given in response to disturbances at their tree holes. I documented the subjects' immediate behavioral responses, including alarm calls, during the first minute following a playback. The sportive lemurs did not give alarm calls in response to predator call playbacks or to playbacks with barks. Other behavioral responses, such as gaze and escape directions, corresponded to the hunting strategies of the two classes of predators, suggesting that the corresponding vocalizations were correctly categorized. In response to barks, they scanned the ground and fled. Because barks do not indicate any specific threats, they are presumably general alarm calls. Thus, sportive lemurs do not rely on early warning of acoustically simulated predators; rather, they show adaptive escape strategies and use general alarm calls that are primarily directed toward the predator but may also serve to warn kin and pair-partners. Am. J. Primatol. 69:611,624, 2007. © 2007 Wiley-Liss, Inc. [source] Gap-crossing decisions of forest birds in a fragmented landscapeAUSTRAL ECOLOGY, Issue 4 2009OLIVER J. ROBERTSON Abstract Habitat loss and fragmentation are recognized as primary drivers of biodiversity loss worldwide. To understand the functional effects of habitat fragmentation on bird populations, data on movement across gaps in habitat cover are necessary, although rarely available. In this study, we used call playback to simulate a conspecific territorial intruder to entice birds to move through the landscape in a predictable and directional manner. We then quantified the probability of movement in continuous forest and across cleared gaps for two forest-dependent species, the grey shrike-thrush (Colluricincla harmonica) and the white-throated treecreeper (Cormobates leucophaeus). Fifty-four playback trials were conducted for each species across distances ranging from 25 to 480 m in continuous forest and 15,260 m across gaps in a forest-agricultural landscape in southern Victoria, Australia. The probability of movement was significantly reduced by gaps in forest cover for both species. Shrike-thrushes were six times more likely to move 170 m in continuous forest than to cross 170-m gaps. The mean probability that treecreepers would cross any gap at all was less than 0.5, and they were three times less likely to move 50 m across a gap than through continuous forest. Both species displayed non-linear responses to increasing gap distance: we identified a gap-tolerance threshold of 85 m for the shrike-thrush and 65 m for the treecreeper beyond which individuals were most unlikely to cross. The presence of scattered paddock trees increased functional connectivity for the shrike-thrush, with individuals crossing up to 260 m when scattered trees were present. We conclude that gaps in habitat cover are barriers to movement, and that characteristics of the intervening matrix influence landscape permeability. [source] Developmental shifts in gene expression in the auditory forebrain during the sensitive period for song learningDEVELOPMENTAL NEUROBIOLOGY, Issue 7 2009Sarah E. London Abstract A male zebra finch begins to learn to sing by memorizing a tutor's song during a sensitive period in juvenile development. Tutor song memorization requires molecular signaling within the auditory forebrain. Using microarray and in situ hybridizations, we tested whether the auditory forebrain at an age just before tutoring expresses a different set of genes compared with later life after song learning has ceased. Microarray analysis revealed differences in expression of thousands of genes in the male auditory forebrain at posthatch day 20 (P20) compared with adulthood. Furthermore, song playbacks had essentially no impact on gene expression in P20 auditory forebrain, but altered expression of hundreds of genes in adults. Most genes that were song-responsive in adults were expressed at constitutively high levels at P20. Using in situ hybridization with a representative sample of 44 probes, we confirmed these effects and found that birds at P20 and P45 were similar in their gene expression patterns. Additionally, eight of the probes showed male,female differences in expression. We conclude that the developing auditory forebrain is in a very different molecular state from the adult, despite its relatively mature gross morphology and electrophysiological responsiveness to song stimuli. Developmental gene expression changes may contribute to fine-tuning of cellular and molecular properties necessary for song learning. © 2009 Wiley Periodicals, Inc. Develop Neurobiol 2009 [source] | |||||||||||||||||||||||||