Call-note discriminations in black-capped chickadees (Poecile atricapillus).

Bioacousticians (M. S. Ficken, S. R. Ficken, & S. R. Witken, 1978) classified black-capped chickadee call notes from the chick-a-dee call complex into 4 note types (A, B, C, and D) identified from sound spectrograms. In Experiment 1, chickadees (Poecile atricapillus) learned operant auditory discriminations both within and between the 4 note types but learned the between note-type discrimination significantly faster. In Experiment 2, when the original, unrewarded between-category exemplars were replaced with novel, rewarded exemplars of these same categories, chickadees showed transfer of inhibitory stimulus control to the novel exemplars. In Experiment 3, when novel exemplars were replaced by the original exemplars, chickadees showed propagation of positive stimulus control back to the original exemplars. This evidence suggests that chickadees and bioacousticians accurately sort conspecific call notes into the same open-ended categories (R. J. Hernstein, 1990). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mechanisms of call note-type perception in black-capped chickadees (Poecile atricapillus): Peak shift in a note-type continuum.

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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Statistical classification of black-capped (Poecile atricapillus) and mountain chickadee (Poecile gambeli) call notes.

Both black-capped (Poecile atricapillus) and mountain chickadees (Poecile gambeli) produce a chick-a-dee call that consists of several distinct note types. In some regions, these 2 species live sympatrically, and it has been shown that 1 species will respond weakly to songs of the other. This suggests that chickadee song, and potentially other of their vocalizations, contains species-specific information. We tested the possibility that call notes were acoustically sufficient for species identification. Black-capped and mountain non-D notes were summarized as a set of 9 features and then analyzed by linear discriminant analysis. Linear discriminant analysis was able to use these notes to identify species with 100% accuracy. We repeated this approach, but with black-capped and mountain D notes that were summarized as a set of 4 features. Linear discriminant analysis was able to use these notes to identify species with 94% accuracy. This demonstrates that any of the note types in these chickadee calls possesses sufficient information for species classification. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Open-ended categorization of chick-a-dee calls by black-capped chickadees (Poecile atricapilla).

The authors trained black-capped chickadees (Poecile atricapilla) in an operant discrimination with exemplars of black-capped and Carolina chick-a-dee calls, with the goal of determining whether the birds memorized the calls of conspecifics and heterospecifics or classified the calls by species. Black-capped calls served as both rewarded (S+) and unrewarded (S-) stimuli (the within-category discrimination), whereas Carolina chick-a-dee calls served as S-s (the between-category discrimination) in the black-capped chick-a-dee call S+ group. The Carolina call S+ group had Carolina calls as S+s and S-s (within-category) and black-capped calls as S-s (between-category). Both groups discriminated between call categories faster than within a call category. In 2 subsequent experiments, both S+ groups showed transfer to novel calls and propagation back to between-category calls. The results favor the hypothesis that the acoustically similar social calls of the 2 species constitute separate open-ended categories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pitch discrimination in field- and isolation-reared black-capped chickadees (Parus atricapillus).

Prior research has shown that male black-capped chickadees (Parus atricapillus) raised in the field produce constant relative pitch cues (frequency ratios) in their songs, whereas males reared in isolation from adult song do not. In this study, the authors found that field-reared male chickadees needed fewer than half as many sessions to learn an operant (go/no-go) auditory discrimination that linked S+ note pairs with a constant-frequency ratio than a discrimination that varied the frequency ratio of S+ pairs randomly. Most important, isolation-reared males needed over 5 times as many sessions to learn the constant-ratio discrimination compared with field-reared males. This is, to the authors' knowledge, the first report of impaired pitch discrimination in isolate songbirds. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A test of the adaptive specialization hypothesis: Population differences in caching, memory, and the hippocampus in black-capped chickadees (Poecile atricapilla).

To test the hypothesis that accurate cache recovery is more critical for birds that live in harsh conditions where the food supply is limited and unpredictable, the authors compared food caching, memory, and the hippocampus of black-capped chickadees (Poecile atricapilla) from Alaska and Colorado. Under identical laboratory conditions, Alaska chickadees (a) cached significantly more food; (b) were more efficient at cache recovery; (c) performed more accurately on one-trial associative learning tasks in which birds had to rely on spatial memory, but did not differ when tested on a nonspatial version of this task; and (d) had significantly larger hippocampal volumes containing more neurons compared with Colorado chickadees. The results support the hypothesis that these population differences may reflect adaptations to a harsh environment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Black-capped chickadees (Poecile atricapillus) anticipate future outcomes of foraging choices.

In 2 experiments we investigated the cognitive abilities of wild-caught black-capped chickadees (Poecile atricapillus) in future anticipation tasks. Chickadees were sensitive to anticipatory contrast effects over time horizons of 5, 10, and 30 min (Experiment 1). Chickadees also learned the order of events and anticipated that the quality of future foraging outcomes was contingent on current foraging choices. This behavior was demonstrated while foraging in a naturalistic aviary environment with a 30-min delay between the initial choice and the future outcome (Experiment 2). These results support the hypothesis that black-capped chickadees can cognitively travel in time both retrospectively and prospectively using episodic memory. This result shows the occurrence of anticipatory cognition in a noncorvid species of food-storing bird and supports the idea that cognitive time travel may have evolved in nonhuman animals in response to specific ecological selection pressures. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hippocampus and memory in a food-storing and in a nonstoring bird species.

Food-storing birds maintain in memory a large and constantly changing catalog of the locations of stored food. The hippocampus of food-storing black-capped chickadees (Panus atricapillus) is proportionally larger than that of nonstoring dark-eyed juncos (Junco hyemalis). Chickadees perform better than do juncos in an operant test of spatial non-matching-to-sample (SNMTS), and chickadees are more resistant to interference in this paradigm. Hippocampal lesions attenuate performance in SNMTS and increase interference. In tests of continuous spatial alternation (CSA), juncos perform better than chickadees. CSA performance also declines following hippocampal lesions. By itself, sensitivity of a given task to hippocampal damage does not predict the direction of memory differences between storing and nonstoring species. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Discrimination of auditory distance cues by black-capped chickadees (Poecile atricapillus) and zebra finches (Taeniopygia guttata).

The authors examined auditory distance perception using a go/no-go operant discrimination task in the laboratory. They taught male black-capped chickadees (Poecile atricapillus) and male zebra finches (Taeniopygia guttata) to discriminate degraded (far) from undegraded (near) versions of male chickadee songs and female zebra finch calls, showing for the 1st time that males can discriminate distance cues in heterospecific vocalizations and in female calls. Chickadees learned faster than zebra finches, and both species learned to discriminate chickadee songs faster than zebra finch calls. Chickadees more than zebra finches attended to amplitude in tests pitting it against other distance cues, demonstrating that amplitude is a potentially useful cue for estimating distance from vocalizations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Song sequence discrimination in the black-capped chickadee (Parus atricapillus).

14 captive black-capped chickadees were presented with normal and altered versions of their species-specific "fee bee" song to determine how note type, number, and sequence affect recognition. Perch changes and vocalizations given in response to playback did not differ reliably as a function of song type, whereas latency to 1st vocalization after playback did. In Exp I, using 2-note songs, Ss vocalized sooner to songs beginning with fee than with bee and to fee bee than to fee fee. In Exp II, Ss were presented with single-note, normal, and 3-note songs each consisting of a single-note type. Habituation slowed responding to altered songs but not to fee bee over 3 test sessions. Results suggest that Ss distinguished (a) single fees and 3-note songs from normal song, (b) single fees from single bees, (c) 2-note songs from 3-note songs, and (d) normal song from altered songs. It is concluded that the internal representation of conspecific song in the chickadee distinguishes between fee and bee notes, contains information about note order, and is sensitive to note number. The pattern of responses is consistent with a model of recognition based on note-by-note integration of individual decisions about song structure. (34 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sun compass and landmark orientation by black-capped chickadees (Parus atricapillus).

Black-capped chickadees (Parus atricapillus), nutcrackers, and jays use a variety of visual cues to relocate and retrieve hidden food caches. Results with scrub jays (Aphelocoma coerulescens) show that sun compass orientation may play an important role in cache retrieval. In a series of experiments, black-capped chickadees were trained to find food along 1 side of an octagonal cage and then subjected to a photoperiodic phase shift to test for the use of sun compass orientation. In some experimental conditions, search was influenced by sun compass information, even when this produced search in conflict with local landmarks. In other conditions, however, there was no indication that birds used the sun compass for orientation. Sun compass orientation by chickadees may depend on the nature and availability of familiar landmarks. Directional information provided by the sun compass is probably integrated with local landmark information, and may require local landmark information, to produce oriented spatial search by chickadees. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Frequency-range discriminations and absolute pitch in black-capped chickadees (Poecile atricapillus), mountain chickadees (Poecile gambeli), and zebra finches (Taeniopygia guttata).

The acoustic frequency ranges in birdsongs provide important absolute pitch cues for the recognition of conspecifics. Black-capped chickadees (Poecile atricapillus), mountain chickadees (Poecile gambeli), and zebra finches (Taeniopygia guttata) were trained to sort tones contiguous in frequency into 8 ranges on the basis of associations between response to the tones in each range and reward. All 3 species acquired accurate frequency-range discriminations, but zebra finches acquired the discrimination in fewer trials and to a higher standard than black-capped or mountain chickadees, which did not differ appreciably in the discrimination. Chickadees' relatively poorer accuracy was traced to poorer discrimination of tones in the higher frequency ranges. During transfer tests, the discrimination generalized to novel tones when the training tones were included, but not when they were omitted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stored and encountered seeds: A comparison of two spatial memory tasks in marsh tits and chickadees.

Tested food-storing birds in 2 spatial memory tasks involving retrieval of stored seeds and retrieval of items encountered while searching. In Exp I, 4 wild-caught marsh tits (Parus palustris) were equally good, after a 2-hr retention interval, at retrieving stored items and items they had encountered while looking for storage sites. Retrieval of encountered seeds did not depend on retracing a route. In Exp II, 3 black-capped chickadees (Parus atricapillus) retrieved seeds 2 hrs after storing them or after "window-shopping." In window-shopping, the Ss encountered seeds behind small plastic windows; during retrieval, the windows were opened. Window-shopped seeds were retrieved above chance level but slightly less well than stored seeds. In this experiment the Ss seemed to rely in part on retracing a route. In Exp III, chickadees (2 from Exp II) were allowed to eat a small piece of seed by each window-shopped item, but this did not improve window-shopping retrieval performance. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hippocampal lesions impair memory for location but not color in passerine birds.

The effects of hippocampal complex lesions on memory for location and color were assessed in black-capped chickadees (Parus atricapillus) and dark-eyed juncos (Junco hyemalis) in operant tests of matching to sample. Before surgery, most birds were more accurate on tests of memory for location than on tests of memory for color. Damage to the hippocampal complex caused a decline in memory for location, whereas memory for color was not affected in the same birds. This dissociation indicates that the avian hippocampus plays an important role in spatial cognition and suggests that this brain structure may play no role in working memory generally. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hippocampus and memory for food caches in black-capped chickadees.

Black-capped chickadees and other food-storing birds recover their scattered caches by remembering the spatial locations of cache sites. Bilateral hippocampal aspiration reduced the accuracy of cache recovery by chickadees to the chance rate, but it did not reduce the amount of caching or the number of attempts to recover caches. In a second experiment, hippocampal aspiration dissociated performance of a task requiring memory for places from performance of a task requiring memory for cues associated with food, disrupting the former but not the latter. On both tasks, however, hippocampal aspiration increased the frequency of revisiting errors to sites previously searched. These experiments show that the structure in the avian brain that is neuroanatomically and embryologically homologous to the mammalian hippocampus shares some functions with the mammalian hippocampus. The results indicate that memory for places and working memory are both disrupted by hippocampal damage in birds. Finally, it was possible to show that these memory capacities are essential for cache recovery by black-capped chickadees. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interrelationships among accuracy in person perception, role taking and the A-B variable.

Administered J. Dublin, C. Elton, and J. Berzin's (see record 1970-03595-001) A-B scale, a programmed case test of accuracy in person perception, and a role-taking task that was assessed for accuracy to 30 male undergraduates. There were positive but very slight relationships among the 2 kinds of accuracy and "A-ness" on the A-B scale. A Ss expressed more negative emotions in the role-taking task than the Bs whereas the Bs were calmer and more businesslike. The pattern of emotional expression of the As in role taking was also very similar to that of Ss who were accurate on the programmed case. Results are interpreted as consistent with a view of A-type individuals as intuitive, empathic, and having easy access to emotional processes, and of B-types as more rational and intellectualized in their approach to interpersonal situations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Group size and social interactions are associated with calling behavior in Carolina chickadees (Poecile carolinensis).

The complexity of a social group may influence the vocal behavior of group members. Recent evidence in Carolina chickadees, Poecile carolinensis, indicated that one component of social complexity, group size, influenced the complexity of the "chick-a-dee" call, a vocalization functioning in social cohesion. Individuals in larger social groups used calls with greater information than did individuals in smaller social groups. Here, the authors review this earlier work, and describe a recent study indicating that social interactions between females and males within female-male pairs of chickadees were associated with rates of chick-a-dee call production in the males. Together, these studies suggest that the nature and complexity of social interactions among members of chickadee social groups influence chick-a-dee calling behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Similarity and complementarity with the A-B scale in verbal conditioning.

Attempted to test the A-B "complementarity" hypothesis. It was predicted that dyadic groups composed of dissimilar A-B pairs would perform better than dyadic groups composed of similar pairs. 40 male undergraduates and 4 male senior-class Es were studied in a verbal conditioning task because of its long-established acceptance as a technique for the testing of interactional personality and therapy variables. In that paradigm, however, a "similarity" hypothesis has been suggested as a possible explanation of "therapeutic effectiveness." A-type Ss conditioned significantly better than B-type Ss regardless of any other factor. Bs decreased their use of the reinforced response class over trials to a degree that was almost significant. The present findings, although not supporting an interactional explanation, support studies that have shown A types to be more facile and active verbally, and to be more sensitive to social cues, than Bs. (15 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Divided attention, memory, and spatial discrimination in food-storing and nonstoring birds, black-capped chickadees ( Poecile atricapilla) and dark-eyed Juncos ( Junco hyemalis).

Food-storing birds, black-capped chickadees (Poecile atricapilla), and nonstoring birds, dark-eyed juncos (Junco hyemalis), matched color or location on a touch screen. Both species showed a divided attention effect for color but not for location (Experiment 1). Chickadees performed better on location than on color with retention intervals up to 40 s, but juncos did not (Experiment 2). Increasing sample-distractor distance improved performance similarly in both species. Multidimensional scaling revealed that both use a Euclidean metric of spatial similarity (Experiment 3). When choosing between the location and color of a remembered item, food storers choose location more than do nonstorers. These results explain this effect by differences in memory for location relative to color, not division of attention or spatial discrimination ability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuron Production, Neuron Number, and Structure Size Are Seasonally Stable in the Hippocampus of the Food-Storing Black-Capped Chickadee (Poecile atricapillus).

Neuronal recruitment in the black-capped chickadee (Poecile atricapillus) hippocampus occurs at a higher rate in the fall than at other times of the year. As a means of determining whether this increase in recruitment results from greater neuron production, chickadees were caught in the wild between October and March and injected with the cell-birth marker 5-bromo-2'-deoxyuridine. Two weeks later, birds were killed by overdose, and hippocampal neuron production, apoptosis, neuron number, and hippocampal volume were determined. Chickadees collected in October, November, January, February, and March did not differ in neuron production, apoptosis, hippocampal volume, or neuron number. These findings indicate that increases in neuronal recruitment in the chickadee hippocampus in the fall do not result from increased neuron production, but instead, enhanced survival of new neurons. (PsycINFO Database Record (c) 2010 APA, all rights reserved)