ZENK expression in the auditory pathway of black-capped chickadees (Poecile atricapillus) as a function of D note number and duty cycle of chick-a- dee calls (original) (raw)
Related papers
Journal of Comparative Psychology, 2010
We report on operant conditioning and artificial neural network (ANN) simulations aimed at further elucidating mechanisms of black-capped chickadee chick-a-dee call note category perception. Specifically, we tested for differences in the speed of acquisition among different discrimination tasks and, in two selected discrimination groups, searched for evidence of peak shift. Earlier, unreported ANN data were instrumental in providing the motivation for the current set of studies with chickadees and are provided here. The ANNs revealed differences in the speed of learning among note-type discrimination groups that is related to the degree of perceptual similarity among the three note types tested (i.e., A, B, and C notes). In many respects, bird and network results were in agreement (i.e., in the observation of peak shift in the same group), but they also differed in important ways (i.e., all discrimination groups showed differences in speed of learning in simulations but not in chickadees). We suggest that the start, peak and end frequency of the chick-a portion of chick-a-dee call notes, which form a graded but overlapping continuum, may drive the peak shift observed.
Zebra finches (Taeniopygia guttata) are sexually dimorphic songbirds, not only in appearance but also in vocal production: while males produce both calls and songs, females only produce calls. This dimorphism provides a means to contrast the auditory perception of vocalizations produced by songbird species of varying degrees of relatedness in a dimorphic species to that of a monomorphic species, species in which both males and females produce calls and songs (e.g., black-capped chickadees, Poecile atricapillus). In the current study, we examined neuronal expression after playback of acoustically similar hetero-and conspecific calls produced by species of differing phylogenetic relatedness to our subject species, zebra finch. We measured the immediate early gene (IEG) ZENK in two auditory areas of the forebrain (caudomedial mesopallium, CMM, and caudomedial nidopallium, NCM). We found no significant differences in ZENK expression in either male or female zebra finches regardless of playback condition. We also discuss comparisons between our results and the results of a previous study conducted by Avey et al. [1] on black-capped chickadees that used similar stimulus types. These results are consistent with the previous study which also found no significant differences in expression following playback of calls produced by various heterospecific species and conspecifics [1]. Our results suggest that, similar to black-capped chickadees, IEG expression in zebra finch CMM and NCM is tied to the acoustic similarity of vocalizations and not the phylogenetic relatedness of the species producing the vocalizations.
Journal of Experimental Biology, 2009
Songbirds often modify elements of their songs or calls in particular social situations (e.g. song matching, flock convergence, etc.) but whether adult individuals also make vocal modifications in response to abiotic environmental factors (e.g. food availability) is relatively unknown. In the present study we test whether two different schedules of food reinforcement, fixed ratio continuous reinforcement and variable ratio partial reinforcement, cause adult black-capped chickadees to change the structure of their chick-a-dee calls. We also examine how these calls differ in two contexts: being alone versus when experiencing an alarming event. Wild-caught black-capped chickadees were housed in isolation to prevent social interaction and recorded weekly for seven weeks. Baseline recordings on week one show that calls given alone differed from those given during an alarming event in both note type composition and frequency (i.e. pitch). Calls also changed over time between birds on the two different schedules of reinforcement. In addition, birds on different reinforcement schedules responded differently during the two recording conditions. Our results suggest that call characteristics can be modified rapidly and may reflect abiotic environmental conditions. If call structure varies consistently with particular abiotic environmental conditions, much can be gained from bioacoustic analyses of calls from wild birds. However, vocal patterns must be consistent across dialects, and we must disentangle vocal changes due to the abiotic environment from those due to social interaction. Further research is needed from natural populations and across multiple regions.
Animal Behaviour, 2002
The chick-a-dee call of the avian genus Poecile is a structurally complex vocal system because it possesses a set of simple rules that governs how the notes of the call are ordered, and variable numbers of each of the note types strung together can generate an extraordinary number of unique calls. Whereas it has been hypothesized that chick-a-dee calls with different notes may convey different information, no experimental evidence has been offered in support of the hypothesis. Previously published studies suggested that flock members use chick-a-dee calls in the context of moving to or from a feeding site. Here, we tested Carolina chickadees' responses to playbacks of chick-a-dee calls that differed in note composition. Playbacks were conducted in the field in the context of a novel food source. Our pilot data had indicated that chick-a-dee calls with relatively large numbers of 'C' notes were given by birds on their first contact with a novel seed stand. In the present study, we found that chickadees flew in close to the playback speaker and subsequently took seed from a seed stand more often during playbacks of chick-a-dee calls containing C notes than chick-a-dee calls not containing C notes or than control playbacks. Vocal responses of chickadees to the playbacks also differed in relation to the particular vocal signal being played back. These results indicate that receivers respond differently to chick-a-dee calls containing different compositions of note types and represent a first step to link variation in note composition and ordering in these calls to possible meanings.
PLoS ONE, 2014
Neuronal populations in the songbird nidopallium increase in activity the most to conspecific vocalizations relative to heterospecific songbird vocalizations or artificial stimuli such as tones. Here, we tested whether the difference in neural activity between conspecific and heterospecific vocalizations is due to acoustic differences or to the degree of phylogenetic relatedness of the species producing the vocalizations. To compare differences in neural responses of black-capped chickadees, Poecile atricapillus, to playback conditions we used a known marker for neural activity, ZENK, in the caudal medial nidopallium and caudomedial mesopallium. We used the acoustically complex 'dee' notes from chick-a-dee calls, and vocalizations from other heterospecific species similar in duration and spectral features. We tested the vocalizations from three heterospecific species (chestnut-backed chickadees, tufted titmice, and zebra finches), the vocalizations from conspecific individuals (black-capped chickadees), and reversed versions of the latter. There were no significant differences in the amount of expression between any of the groups except in the control condition, which resulted in significantly less neuronal activation. Our results suggest that, in certain cases, neuronal activity is not higher in response to conspecific than in response to heterospecific vocalizations for songbirds, but rather is sensitive to the acoustic features of the signal. Both acoustic features of the calls and the phylogenetic relationship between of the signaler and the receiver interact in the response of the nidopallium.
Operant discrimination of relative frequency ratios in black-capped chickadee song
Animal Cognition
The two-note fee bee song of the black-capped chickadee (Poecile atricapillus) is sung at many different absolute frequencies, but the relative frequencies, or ''pitch ratios'', between the start and end of the fee note (glissando) and the fee and the bee notes (inter-note interval) are preserved with each pitch-shift. Ability to perceive these ratios and their relative salience varies with sex of the bird and setting: while both sexes appear to perceive changes in the inter-note interval, males appear to attend to the glissando in the field, and females appear to attend to both ratios. In this study, we compared directly whether male and female chickadees could discriminate between normal fee bee songs and songs that had one or both of the pitch ratios altered, and whether birds attended to one type of alteration over another. Both sexes learned to discriminate normal from altered songs; songs lacking an inter-note interval were more easily discriminated than songs with only the glissando removed. Females performed slightly better than males, including in the most difficult task with the stimuli lacking the glissando. Our study illustrates the value of using perceptual tasks to directly compare performance between the sexes and to demonstrate the difference between perception of and attention to acoustic features of vocal communication.
Posttranscriptional regulation of zenk expression associated with zebra finch vocal development
Molecular Brain Research, 2000
In the male zebra finch, highly variable juvenile song and stereotyped adult song induce mRNA expression of the immediate early gene zenk in telencephalon. However, the functional consequences of this behavior-driven gene expression remain unknown. Here we characterize the developmental expression of zenk mRNA and protein in two forebrain song regions (HVC, the higher vocal center, and RA, the robust nucleus of the archistriatum). In HVC, singing results in similar percentages of cells producing zenk mRNA and zenk protein at different stages of vocal development. Similarly, song behavior at all stages of vocal development induces a comparable percentage of RA cells expressing zenk mRNA. However, the percentage of RA zenk immunoreactive cells is low during early vocal learning, increasing only as the vocal pattern matures. Early induction of a stereotyped vocal pattern in juvenile birds is associated with increased zenk immunoreactivity in RA, indicating that it is the form of the behavior (and not the age of the bird) that correlates with changes in zenk immunoreactivity. Together, our findings reveal a previously unrecognized relationship between behavioral development and post-transcriptional gene regulation.
ZENK protein regulation by song in the brain of songbirds
The Journal of Comparative Neurology, 1998
When songbirds hear the song of another individual of the same species or when they sing, the mRNA levels of the ZENK gene increase rapidly in forebrain areas involved in vocal communication. This gene induction is thought to be related to long-term neuronal change and possibly the formation of song-related memories. We used immunocytochemistry to study the levels and distribution of ZENK protein in the brain of zebra finches and canaries after presentation of song playbacks. Birds that heard the playbacks and did not sing in response showed increased ZENK protein levels in auditory brain areas, including the caudomedial neostriatum and hyperstriatum ventrale, fields L1 and L3, the shelf adjacent to the high vocal center (HVC), the cup adjacent to the nucleus robustus archistriatalis (RA), and the nucleus mesencephalicus lateralis pars dorsalis (MLd). No ZENK expression was seen in song nuclei in these birds. Males that sang in response to the playbacks showed, in addition to auditory areas, increased ZENK protein in several song control nuclei, most prominently in HVC, RA, area X, and the dorsomedial nucleus (DN) of the intercollicular complex. The rise in ZENK protein followed that described previously for ZENK mRNA by a short lag, and the distribution of ZENK-labeled cells was in agreement with previous analysis of mRNA distribution. Thus, ZENK protein regulation can be used to assess activation of brain areas involved in perceptual and motor aspects of song. Possible implications of ZENK induction in these areas are discussed.
Frontiers in Psychology, 2010
Previous perceptual research with black-capped and mountain chickadees has demonstrated that these species treat each other's namesake chick-a-dee calls as belonging to separate, open-ended categories. Further, the terminal dee portion of the call has been implicated as the most prominent species marker. However, statistical classification using acoustic summary features suggests that all note-types contained within the chick-a-dee call should be sufficient for species classification. The current study seeks to better understand the note-type based mechanisms underlying species-based classification of the chick-a-dee call by black-capped and mountain chickadees. In two, complementary, operant discrimination experiments, both species were trained to discriminate the species of the signaler using either entire chick-a-dee calls, or individual note-types from chick-a-dee calls. In agreement with previous perceptual work we find that the D note had significant stimulus control over species-based discrimination. However, in line with statistical classifications, we find that all note-types carry species information. We discuss reasons why the most easily discriminated note-types are likely candidates to carry species-based cues.
Sound sequences in birdsong: how much do birds really care?
Philosophical Transactions of the Royal Society B: Biological Sciences, 2019
The complex and melodic nature of many birds' songs has raised interest in potential parallels between avian vocal sequences and human speech. The similarities between birdsong and speech in production and learning are well established, but surprisingly little is known about how birds perceive song sequences. One popular laboratory songbird, the zebra finch ( Taeniopygia guttata ), has recently attracted attention as an avian model for human speech, in part because the male learns to produce the individual elements in its song motif in a fixed sequence. But psychoacoustic evidence shows that adult zebra finches are relatively insensitive to the sequential features of song syllables. Instead, zebra finches and other birds seem to be exquisitely sensitive to the acoustic details of individual syllables to a degree that is beyond human hearing capacity. Based on these findings, we present a finite-state model of zebra finch perception of song syllable sequences and discuss the rich...