Mechanisms of Communication and Cognition in Chickadees: Explaining Nature in the Lab and Field (original) (raw)
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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.
The black-capped chickadee is a songbird that has been used extensively as a model of animal communication in field and laboratory settings. Although many studies have focused on the complex call and song systems of the black-capped chickadee, relatively fewer studies have focused on chickadee audition. However, we do know from behavioral and molecular work that chickadees (and auditory processing areas in their brains) discriminate between artificially generated tones, between conspecific and heterospecific vocalizations, and among different types of conspecific vocalizations. In this paper we investigate peripheral auditory processing of frequency in the black-capped chickadee and the potential influence of sex on frequency sensitivity using a technique called auditory evoked potentials. We found that male and female black-capped chickadees did not differ in any measure of frequency sensitivity. Both sexes had the greatest sensitivity to frequencies between 2 and 4 kHz. This range of frequencies is well represented in black-capped chickadee song, partially supporting the idea that sender and receiver coevolve. Finally, we suggest that the call and song system of North American parids make them an ideal taxonomic group for comparative work exploring the relationship between call systems and the evolution of auditory processing.
Journal of The Acoustical Society of America, 2011
The tseet contact call, common to black-capped (Poecile atricapillus) and mountain chickadees (P. gambeli), is the most frequently produced vocalization of each species. Previous work has characterized the tseet call of black-capped and mountain chickadees from different geographic locations in terms of nine acoustic features. In the current study, using similar methods, the tseet call of black-capped chickadees that were hand reared with either conspecifics, heterospecifics (mountain chickadees), or in isolation from adult chickadees are described. Analysis of call features examined which acoustic features were most affected by rearing environment, and revealed that starting frequency and the slope of the descending portion of the tseet call differed between black-capped chickadees reared with either conspecific or heterospecific adults. Birds reared in isolation from adults differed from the other hand-reared groups on almost every acoustic feature. Chickadee tseet calls are more individualized when they are reared with adult conspecifics or heterospecifics compared to chickadees that are reared in isolation from adults. The current results suggest a role of learning in this commonly used contact call.
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.
Auditory processing of vocal sounds in birds
Current Opinion in Neurobiology, 2006
The avian auditory system has become a model system to investigate how vocalizations are memorized and processed by the brain in order to mediate behavioral discrimination and recognition. Recent studies have shown that most of the avian auditory system responds preferentially and efficiently to sounds that have natural spectro-temporal statistics. In addition, neurons in secondary auditory forebrain areas have plastic response properties and are the most active when processing behaviorally relevant vocalizations. Physiological measurements show differential responses for vocalizations that were recently learned in discrimination tasks, and for the tutor song, a longer-term auditory memory that is used to guide vocal learning in male songbirds.
Behavioral Ecology and Sociobiology, 2004
Chick-a-dee calls in many chickadee (Poecile) species are common vocal signals used in a diversity of social contacts. The calls consist of four notes, A, B, C, and D, which follow simple rules of syntax (note ordering and composition) to generate many unique call types. We used field playbacks with Carolina chickadees, P. carolinensis, to ask whether violations of a syntactical rule affected their vocal responses. We show that chickadee responses to typical calls (e.g. AAAACCCC and CCC-CDDDD) differ from responses to atypical calls (e.g. CACACACA and DCDCDCDC) depending on playback note composition, season, and social context (presence of heterospecifics). In the fall/winter, playbacks of typical calls with A and C notes elicited the greatest number of A and B notes in chick-a-dee call responses and typical calls with D notes elicited the greatest number of C notes, when in the presence of heterospecifics. In contrast, the corresponding atypical calls did not elicit similar responses. This suggests communicative significance is lost in calls that violate a rule of syntax in the fall/winter. In the spring, neither chickadee feebeefeebay song rate nor chick-a-dee calls responses differed by playback type. We suggest that call syntax is less salient for mated pairs in the spring than it is for fall/winter flocks that rely more on conspecific communication for foraging success and flock cohesion. This study represents the first experimental evidence that chickadees attend to both note composition and ordering in chick-a-dee calls.
Brain, Behavior and Evolution, 2019
Acoustic communication signals are typically generated to influence the behavior of conspecific receivers. In songbirds, for instance, such cues are routinely used by males to influence the behavior of females and rival males. There is remarkable diversity in vocalizations across songbird species, and the mechanisms of vocal production have been studied extensively, yet there has been comparatively little emphasis on how the receiver perceives those signals and uses that information to direct subsequent actions. Here, we emphasize the receiver as an active participant in the communication process. The roles of sender and receiver can alternate between individuals, resulting in an emergent feedback loop that governs the behavior of both. We describe three lines of research that are beginning to reveal the neural mechanisms that underlie the reciprocal exchange of information in communication. These lines of research focus on the perception of the repertoire of songbird vocalizations,...
Animal Behaviour, 2010
Keywords: audiogram auditory brainstem response (ABR) auditory filter Carolina chickadee coevolution frequency resolution frequency selectivity notched noise Poecile carolinensis vocal communication Chickadees produce elaborate vocalizations, but their basic auditory capabilities remain unexplored. We used auditory brainstem responses to tone bursts to assess the auditory sensitivity of Carolina chickadees at frequencies from 0.5 to 8 kHz and the percentage of frequency selectivity (quality) of auditory filters at frequencies from 2 to 4 kHz. The high-frequency limit of sensitive hearing was relatively high in chickadees compared to other songbirds tested using the same method, while the low-frequency limit was similar among species. These results support a previously noted correlation across songbirds between the high-frequency limit of sensitive hearing and the maximum frequency of vocalizations. The frequency selectivity of auditory filters in chickadees increased with increasing frequency. Frequency selectivity was intermediate compared to other species at 2 and 3 kHz, and relatively high at 4 kHz. This pattern suggests that frequency selectivity is generally greatest within the frequency range of long-range communication signals, and maximum frequency selectivity may be greater in woodland species than in open habitat species. Greater frequency selectivity may have evolved for greater frequency resolution of vocal signals, which are relatively tonal in woodland species, or for better signal detection in noise. Finally, males had greater auditory sensitivity than females, whereas females had greater frequency selectivity than males. Greater frequency selectivity may enhance perception of the frequency difference between song notes, which indicates male quality in another chickadee species. Ó
Animal cognition, 2017
Chickadees produce a multi-note chick-a-dee call in multiple socially relevant contexts. One component of this call is the D note, which is a low-frequency and acoustically complex note with a harmonic-like structure. In the current study, we tested black-capped chickadees on a between-category operant discrimination task using vocalizations with acoustic structures similar to black-capped chickadee D notes, but produced by various songbird species, in order to examine the role that phylogenetic distance plays in acoustic perception of vocal signals. We assessed the extent to which discrimination performance was influenced by the phylogenetic relatedness among the species producing the vocalizations and by the phylogenetic relatedness between the subjects' species (black-capped chickadees) and the vocalizers' species. We also conducted a bioacoustic analysis and discriminant function analysis in order to examine the acoustic similarities among the discrimination stimuli. A p...