ORCID Profile
0000-0003-0027-3095
Current Organisations
Central Adelaide Local Health Network
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University of Adelaide
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Publisher: Elsevier
Date: 2017
Publisher: Elsevier BV
Date: 06-2010
DOI: 10.1016/J.BEPROC.2010.02.018
Abstract: We studied the effects of cue competition on timing in both overshadowing and blocking operant procedures with pigeons. A white center key delivered reward when pecked 30s after a red or green sidekey was presented and 10s after presentation of the alternate color on the other sidekey. In Experiment 1, key presentations were concurrent during training trials for overshadow-condition pigeons, while side key presentations were separated across training trials for control birds. In Experiment 2, half of the birds (Blocking group) were given pre-exposure trials to either the 10-s or 30-s sidekey condition. Both blocking-condition and control birds were then given trials of concurrent side key presentations. Peak time curves were compared between experimental and control conditions. The results showed blocking of timing accuracy of a long (30-s) stimulus by a short (10-s) stimulus, but no evidence for overshadowing of timing accuracy.
Publisher: Springer Science and Business Media LLC
Date: 15-03-2013
DOI: 10.3758/S13420-013-0106-X
Abstract: We explored pigeons' ability to learn a particular sequence of stimuli in which the durations of each stimulus varied among trials, where the first response at the end of the sequence was reinforced. In Experiment 1A, we found that pigeons failed to use the whole sequence of three stimuli to predict food reinforcement, and instead responded only to the third, "rewarded" stimulus. When rewarded (1-2-3) and nonrewarded (2-1-3) sequences were used in a go/no-go procedure in Experiment 1B, however, pigeons showed a tendency to rank-order responding, with higher response rates to the second than to the first stimulus, as well as lower response rates to the third stimulus on nonrewarded-sequence trials. In Experiment 2, pigeons showed rudimentary rank-ordering of five stimuli in sequence, with lower responding to the final stimulus on nonrewarded trials, even when the sequence presented differed from the rewarded sequence only in a reversal of the second and third stimuli. Pigeons were capable of using ordinal information in a temporal task, but only when that information was easily discriminable and led to explicit consequences (i.e., rewarded vs. nonrewarded sequences).
Publisher: Elsevier BV
Date: 07-2015
DOI: 10.1016/J.BBR.2015.03.021
Abstract: Black-capped chickadees (Poecile atricapillus) produce numerous vocalizations, including the acoustically complex chick-a-dee call that is composed of A, B, C, and D notes. D notes are longer in duration and lower in frequency than the other note types and contain information regarding flock and species identification. Adult wild-caught black-capped chickadees have been shown to have similar amounts of immediate early gene (IEG) expression following playback of vocalizations with harmonic-like acoustic structure, similar to D notes. Here we examined how different environmental experiences affect IEG response to conspecific D notes. We hand-reared black-capped chickadees under three conditions: (1) with adult conspecifics, (2) with adult heterospecific mountain chickadees, and (3) without adults. We presented all hand-reared birds and a control group of field-reared black-capped chickadees, with conspecific D notes and quantified IEG expression in the caudomedial mesopallium (CMM) and caudomedial nidopallium (NCM). We found that field-reared birds that heard normal D notes had a similar neural response as a group of field-reared birds that heard playback of reversed D notes. Field-reared birds that heard normal D notes also had a similar neural response as birds reared with adult conspecifics. Birds reared without adults had a significantly reduced IEG response, whereas the IEG expression in birds reared with heterospecifics was at intermediate levels between birds reared with conspecifics and birds reared without adults. Although acoustic characteristics have been shown to drive IEG expression, our results demonstrate that experience with adults or normal adult vocalizations is also an important factor.
Publisher: Springer Science and Business Media LLC
Date: 17-02-2016
DOI: 10.1007/S10071-016-0962-9
Abstract: Animals make surprising anticipatory and perseverative errors when faced with a midsession reversal of reinforcer contingencies on a choice task with highly predictable stimulus-time relationships. In the current study, we asked whether pigeons would anticipate changes in reinforcement when the reinforcer contingencies for each stimulus were not fixed in time. We compared the responses of pigeons on a simultaneous choice task when the initially correct stimulus was randomized or alternated across sessions. Pigeons showed more errors overall compared with the typical results of a standard midsession reversal procedure, and they did not show the typical anticipatory errors prior to the contingency reversal. Probe tests that manipulated the spacing between trials also suggested that timing of the session exerted little control of pigeons' behavior. The temporal structure of the experimental session thus appears to be an important determinant for animals' use of time in midsession reversal procedures.
Publisher: American Psychological Association (APA)
Date: 2009
DOI: 10.1037/A0013722
Abstract: In 4 experiments, the authors asked whether pigeons (Columba livia) would show metamemory by choosing to study a s le stimulus before taking a memory test. In Experiments 1a-1c, pigeons chose between cues that led either to exposure to a s le stimulus or directly to the comparison test stimuli without seeing the s le in a delayed matching-to-s le task. The same choice was used in Experiment 2 to see whether pigeons would take a reminder when memory of the s le was weak. In Experiments 3 and 4, pigeons' responses led to either a choice between red and green side keys with a s le present to guide the choice or a choice with no s le present. The findings of all of these experiments suggest the absence of metamemory in pigeons.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 04-04-2008
Abstract: Recent experiments with rats suggest that they show episodic-like or what-where-when memory for a preferred food found on a radial maze. Although memory for when a salient event occurred suggests that rats can mentally travel in time to a moment in the past, an alternative possibility is that they remember how long ago the food was found. Three groups of rats were tested for memory of previously encountered food. The different groups could use only the cues of when, how long ago, or when + how long ago. Only the cue of how long ago food was encountered was used successfully. These results suggest that episodic-like memory in rats is qualitatively different from human episodic memory.
Publisher: American Psychological Association (APA)
Date: 12-2018
DOI: 10.1037/XGE0000414
Abstract: Extreme stimuli are often more salient in perception and memory than moderate stimuli. In risky choice, when people learn the odds and outcomes from experience, the extreme outcomes (best and worst) also stand out. This additional salience leads to more risk-seeking for relative gains than for relative losses-the opposite of what people do when queried in terms of explicit probabilities. Previous research has suggested that this pattern arises because the most extreme experienced outcomes are more prominent in memory. An important open question, however, is what makes these extreme outcomes more prominent? Here we assess whether extreme outcomes stand out because they fall at the edges of the experienced outcome distributions or because they are distinct from other outcomes. Across four experiments, proximity to the edge determined what was treated as extreme: Outcomes at or near the edge of the outcome distribution were both better remembered and more heavily weighted in choice. This prominence did not depend on two metrics of distinctiveness: lower frequency or distance from other outcomes. This finding adds to evidence from other domains that the values at the edges of a distribution have a special role. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
Publisher: Elsevier BV
Date: 04-2022
Publisher: American Psychological Association (APA)
Date: 11-2014
DOI: 10.1037/A0036562
Abstract: Pigeons (Columba livia) produce many anticipatory and perseverative errors on discrimination tasks with a reversal of reward contingencies partway through the session. Prior comparative research has suggested that rats (Rattus norvegicus) do not show the same number of errors and produce results that more closely resemble those of humans. We examined pigeons' performance on a visual-spatial discrimination with the reversal point randomized within the session and found that they showed remarkably few errors. When these subjects were split into groups with the contingencies for reward unconfounded, the birds in the spatial-contingency group maintained their performance, and those in the visual-contingency group made many more anticipatory and perseverative errors. We also examined the performance of naïve pigeons on a spatial midsession reversal task and found a pattern of results similar to those shown by pigeons that had previously been trained on a visual-spatial reversal procedure. Finally, we studied rats on a T-maze using a spatial-discrimination midsession reversal task and found that the rats showed a large number of anticipatory and perseverative errors. Near-perfect performance on the midsession reversal task appears to be subject to the ability of the animal to orient spatially during the intertrial interval, rather than being due to broad species differences.
Publisher: Comparative Cognition Society
Date: 2017
Publisher: Cambridge University Press
Date: 22-06-2017
Publisher: Elsevier BV
Date: 06-2015
Publisher: Elsevier BV
Date: 02-2019
DOI: 10.1016/J.BEPROC.2018.12.016
Abstract: In a two-stimulus visual discrimination choice task with a reversal in reward contingencies midway through each session, pigeons produce a surprising number of anticipatory errors (i.e., responding to the second-correct stimulus before the reversal) based on failure to inhibit timing-based intrusion errors limited prior research has suggested humans' performance is qualitatively different. Here we illustrate a partial replication of previous findings in humans, but suggest based on our results that humans process these tasks in a manner similar to pigeons. Humans made relatively few but consistent errors across both simultaneous- and successive-choice experiments. Anticipation errors were limited when the identity of the first-correct stimulus alternated between sessions, consistent with the behaviour of pigeons. Subsequent experiments found evidence for anticipation on a purely temporal simultaneous choice task, and fewer errors with symmetrical reinforcement and punishment of responses on a sequential choice task. Interval timing causes conflicts with decision-making processes on the midsession reversal task that are consistent, but differ in magnitude, across species.
Publisher: University of Alberta Libraries
Date: 2016
DOI: 10.7939/R3FQ9QH5C
Publisher: Springer Science and Business Media LLC
Date: 05-04-2017
DOI: 10.1007/S10071-017-1088-4
Abstract: Chickadees are high-metabolism, non-migratory birds, and thus an especially interesting model for studying how animals follow patterns of food availability over time. Here, we studied whether black-capped chickadees (Poecile atricapillus) could learn to reverse their behavior and/or to anticipate changes in reinforcement when the reinforcer contingencies for each stimulus were not stably fixed in time. In Experiment 1, we examined the responses of chickadees on an auditory go/no-go task, with constant reversals in reinforcement contingencies every 120 trials across daily testing intervals. Chickadees did not produce above-chance discrimination however, when trained with a procedure that only reversed after successful discrimination, chickadees were able to discriminate and reverse their behavior successfully. In Experiment 2, we examined the responses of chickadees when reversals were structured to occur at the same time once per day, and chickadees were again able to discriminate and reverse their behavior over time, though they showed no reliable evidence of reversal anticipation. The frequency of reversals throughout the day thus appears to be an important determinant for these animals' performance in reversal procedures.
Publisher: Springer Science and Business Media LLC
Date: 09-04-2017
DOI: 10.1007/S10071-017-1087-5
Abstract: 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 previous study has shown that neural activation in black-capped chickadee auditory and perceptual brain regions is similar following the presentation of these vocalization categories. However, we found that chickadees had difficulty discriminating between forward and reversed black-capped chickadee D notes, a result that directly corresponded to the bioacoustic analysis indicating that these stimulus categories were acoustically similar. In addition, our results suggest that the discrimination between vocalizations produced by two parid species (chestnut-backed chickadees and tufted titmice) is perceptually difficult for black-capped chickadees, a finding that is likely in part because these vocalizations contain acoustic similarities. Overall, our results provide evidence that black-capped chickadees' perceptual abilities are influenced by both phylogenetic relatedness and acoustic structure.
Publisher: Center for Open Science
Date: 18-08-2017
Abstract: Extreme stimuli are often more salient in perception and memory than moderate stimuli. In risky choice, when people learn the odds and outcomes from experience, the extreme outcomes (best and worst) also stand out. This additional salience leads to more risk-seeking for relative gains than for relative losses—the opposite of what people do when queried in terms of explicit probabilities. Previous research has suggested that this pattern arises because the most extreme experienced outcomes are more prominent in memory. An important open question, however, is what makes these extreme outcomes more prominent? Here we assess whether extreme outcomes stand out because they fall at the edges of the experienced outcome distributions or because they are distinct from other outcomes. Across four experiments, proximity to the edge determined what was treated as extreme: Outcomes at or near the edge of the outcome distribution were both better remembered and more heavily weighted in choice. This prominence did not depend on two metrics of distinctiveness: lower frequency or distance from other outcomes. This finding adds to evidence from other domains that the values at the edges of a distribution have a special role.
Publisher: Frontiers Media SA
Date: 14-10-2015
Publisher: Elsevier BV
Date: 07-2017
DOI: 10.1016/J.BBR.2017.05.023
Abstract: 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.
Publisher: Comparative Cognition Society
Date: 2012
Publisher: Wiley
Date: 16-03-2015
DOI: 10.1002/WCS.1346
Abstract: Although birds have traditionally and colloquially been considered less cognitively complex than mammals, and especially primates, more recent research has consistently refuted these assumptions. We argue that the impressive abilities of birds to navigate and communicate require considerable information‐processing capabilities. These capacities include collecting, organizing, and selecting from a wide variety of navigational cues to orient toward and find a goal location in the spatial domain, and utilizing open‐ended categorization and possibly even abstract reasoning to discriminate species‐specific acoustic features of songs and calls. Furthermore, these abilities may be present across many avian species, providing evidence for domain‐general cognitive facilities. We provide ex les of processes in spatial learning and communication in birds, and locate them within the general literature, as evidence that the term ‘bird‐brain’ should not be considered a pejorative. WIREs Cogn Sci 2015, 6:285–297. doi: 10.1002/wcs.1346 This article is categorized under: Psychology Comparative Psychology
Publisher: Springer Science and Business Media LLC
Date: 06-05-2016
DOI: 10.1007/S10071-016-0989-Y
Abstract: Roads are a nearly ubiquitous feature of the developed world, but their presence does not come without consequences. Many mammals, birds, reptiles, and hibians suffer high rates of mortality through collision with motor vehicles, while other species treat roads as barriers that reduce gene flow between populations. Road effects extend beyond the pavement, where traffic noise is altering communities of songbirds, insects, and some mammals. Traditional methods of mitigation along roads include the creation of quieter pavement and tires and the construction of physical barriers to reduce sound transmission and movement. While effective, these forms of mitigation are costly and time-consuming. One alternative is the use of learning principles to create or extinguish aversive behaviors in animals living near roads. Classical and operant conditioning are well-documented techniques for altering behavior in response to novel cues and signals. Behavioral ecologists have used conditioning techniques to mitigate human-wildlife conflict challenges, alter predator-prey interactions, and facilitate reintroduction efforts. Yet, these principles have rarely been applied in the context of roads. We suggest that the field of road ecology is ripe with opportunity for experimentation with learning principles. We present tangible ways that learning techniques could be utilized to mitigate negative roadside behaviors, address the importance of evaluating fitness within these contexts, and evaluate the longevity of learned behaviors. This review serves as an invitation for empirical studies that test the effectiveness of learning paradigms as a mitigation tool in the context of roads.
Publisher: American Psychological Association (APA)
Date: 2012
DOI: 10.1037/A0030192
Abstract: It has been shown previously that pigeons make surprising errors on a visually based midsession reversal task (Cook & Rosen, 2010 Rayburn-Reeves, Molet, & Zentall, 2011). We trained birds with red and green sidekeys, with one color rewarded in the first 40 trials (S1) and the other color rewarded in the latter 40 trials (S2). Importantly, in Phases 1 and 3, red and green were always presented on the same side, whereas in Phase 2 sidekeys were presented on the left and right equally often. In Phases 2 and 3, probe sessions with intertrial intervals (ITIs) longer or shorter than the training intertribal interval (ITI) were interjected among baseline sessions. Results showed that pigeons presented with visual-only cues used interval duration since the beginning of the session to predict when the reversal of reward contingency would occur, but pigeons presented with color and spatial dimensions confounded for predicting reward tended to use a more optimal reward-following strategy of choice based on local reinforcement.
Publisher: American Psychological Association (APA)
Date: 2015
DOI: 10.1037/XAN0000058
Abstract: In a 2-stimulus visual discrimination choice task with a reversal in reward contingencies midway through each session, pigeons produce a surprising number of both anticipatory errors (i.e., responding to the second-correct stimulus before the reversal) and perseverative errors (i.e., responding to the first-correct stimulus after the reversal). Here, we used a go/no-go version of the task to examine the degree to which these errors can be attributed to failure to inhibit incorrect responses near the reversal. We presented pigeons with either a green or red stimulus (randomized across trials), with pecks to 1 reinforced with food and pecks to the other stimulus leading to a 10-s time-out the reward versus time-out contingencies reversed after 40 trials. Pigeons rarely withheld responses when reward was provided for pecking, but produced many incorrect pecks near the reversal. Subsequent experiments examined these errors with longer sessions and multiple reversals, as well as on choice tasks. Our results suggest that pigeons' errors may be due to an inability to inhibit incorrect responses rather than a deliberate choice of the incorrect stimulus on simultaneous discrimination midsession reversal procedures. Results suggest that pigeons learned independent rules about the 2 stimuli, and that training with multiple reversals changed the rules that governed pigeons' responding. (PsycINFO Database Record
Publisher: American Psychological Association (APA)
Date: 2013
DOI: 10.1037/A0032470
Abstract: Two groups of pigeons were trained to respond on a white center key to a fixed-interval, 60-s schedule of reinforcement signaled by the onset of a side-key cue (S+ training). In additional training sessions, S+ trials alternated between S- trials in which a different side-key cue signaled nonreinforcement after 60 s (S+/S- training). For one group, S+/S- training sessions followed S+ training, and for the other group, S+/S- training preceded S+ training. Peak-time curves obtained from extended nonrewarded probe trials inserted among training trials showed loss of control by time during S+/S- training relative to S+ training. A follow-up experiment showed that this result was not caused by a difference in probability of reinforcement. We suggest that attention to time was weakened by the introduction of visual cues that were more valid predictors of trial outcomes.
Publisher: Elsevier BV
Date: 02-2016
Publisher: American Psychological Association (APA)
Date: 2014
DOI: 10.1037/XAN0000018
Abstract: In 2 experiments, rats were trained to press a centrally located lever that delivered immediate food reinforcement and turned on a light signal that indicated the location of a further food reward. After rats learned to press the lever and use the light cue to find food, immediate reinforcement for lever pressing was discontinued. In Experiment 1, rats continued to press the lever for information about the location of reward in a T-maze, but control groups yoked to the experimental group for amount of reward, and conditioned reinforcement showed complete extinction of lever pressing. Rats tested on an 8-arm radial maze in Experiment 2 also continued to press a lever that did not yield immediate reinforcement but provided a light cue indicating which randomly chosen arm of the maze contained food lever pressing declined significantly, however, when the same arm contained food on every trial. Comparisons of testing conditions between and within experiments suggested that probability of lever pressing increased as the amount of information gained increased. The comparative implications of these findings for metacognition are discussed.
Publisher: American Psychological Association (APA)
Date: 12-2017
DOI: 10.1037/XLM0000416
Abstract: The authors investigated how humans use multiple landmarks to locate a goal. Participants searched for a hidden goal location along a line between 2 distinct landmarks on a computer screen. On baseline trials, the location of the landmarks and goal varied, but the distance between each of the landmarks and the goal was held constant, with 1 landmark always closer to the goal. In Experiment 1, some baseline trials provided both landmarks, and some provided only 1 landmark. On probe trials, both landmarks were shifted apart relative to the previously learned goal location. Participants searched between the locations specified by the 2 landmarks and their search locations were shifted more toward the nearer landmark, suggesting a weighted integration of the conflicting landmarks. Moreover, the observed variance in search responses when both cues were presented in their normal locations was reduced compared to the variance on tests with single landmarks. However, the variance reduction and the weightings of the landmarks did not always show Bayesian optimality. In Experiment 2, some participants were trained only with each of the single landmarks. On subsequent tests with the 2 cues in conflict, searching did not shift toward the nearer landmark and the variance of search responses of these single-cue trained participants was larger than their variance on single-landmark tests, and even larger than the variance predicted by using the 2 landmarks alternatively on different trials. Taken together, these results indicate that cue combination occurs only when the landmarks are presented together during the initial learning experience. (PsycINFO Database Record
Publisher: Elsevier BV
Date: 05-2008
DOI: 10.1016/J.BEPROC.2007.11.012
Abstract: Previous research has suggested that using stationary and moving levers as nonspatial response alternatives can significantly enhance the speed of acquiring a temporal discrimination in rats. In Experiment 1, rats were trained to discriminate 2 and 8s of magazine light illumination by responding to either a stationary lever or a moving lever with a cue light illuminated above it. Rats learned to discriminate event durations at a high level of accuracy after 25 sessions of training. During subsequent delay tests, rats exhibited a strong choose-long bias, indicating that they were timing from the onset of the magazine light until the entry of levers into the chamber. This occurred regardless of whether intertrial intervals and delay intervals were dark or illuminated. On test trials in which the s le was omitted, rats responded as if the short s le had been presented. In Experiment 2, the rats received extensive training with dark and illuminated variable delay intervals (1-4 s). However, they continued to exhibit a tendency to time from the onset of the magazine light until entry of the levers into the chamber. Although the use of stationary/uncued and moving/cued levers as response alternatives enhanced the speed of acquisition of the event duration discrimination in rats, additional procedural modifications will be necessary to prevent rats from timing during the delay interval.
Publisher: Springer Science and Business Media LLC
Date: 17-09-2015
DOI: 10.1007/S10071-014-0808-2
Abstract: In a two-stimulus visual discrimination task with a reversal in reward contingencies midway through each session, pigeons produce a surprising number of both anticipatory (i.e., before the reversal) and perseverative (i.e., after the reversal) errors. In the current work, we examined pigeons' (Columba livia) patterns of responding on a 90-trial, three-stimulus visual or spatial discrimination task with two changes in reward contingency (one after Trial 30 and one after Trial 60) during each session. On probe sessions where pecking the first-correct stimulus was rewarded for the first 60 rather than 30 trials, pigeons on a spatial discrimination pecked the first-correct stimulus until it was no longer rewarded, while visual discrimination birds ceased responding to the first-correct stimulus even while it was still being rewarded. On probe sessions where the onset of the first trial was delayed 7 min, pigeons' performance on the visual discrimination was disrupted by the interval delay, but performance in the spatial condition was more similar to baseline. Pigeons use different strategies (temporal control vs. local reinforcement) on midsession reversal tasks with visual versus spatial stimuli, suggesting that they are selectively permeable to changes in information (global vs. local reinforcement rates).
Publisher: International Society of Comparative Psychology
Date: 2016
DOI: 10.46867/IJCP.2016.29.00.16
Abstract: Chickadees produce many vocalizations, including chick-a-dee calls which they use as a mobbing call in the presence of predators. Previous research has shown that chickadees produce more D notes in their mobbing calls in response to high-threat predators compared to low-threat predators, and may perceive predator and corresponding mobbing vocalizations as similar. We presented black-capped chickadees with playback of high- and low-threat predator calls and conspecific mobbing calls, and non-threat heterospecific and reversed mobbing calls, to examine vocal and movement behavioural responses. Chickadees produced more chick-a-dee calls in response to playback of calls produced by a high-threat predator compared to calls produced by a low-threat predator, and to reversed high-threat mobbing calls compared to normal (i.e., non-reversed) high-threat mobbing calls. Chickadees also vocalized more in response to all playback conditions consisting of conspecific mobbing calls compared to a silent baseline period. The number of D notes that the subjects produced was similar to previous findings chickadees produced approximately one to three D notes per call in response to low-threat mobbing calls, and produced more calls containing four to five D notes in response to high-threat mobbing calls, although this difference in the number of D notes per call was not significant. The difference in chickadees’ production of tseet calls across playback conditions approached significance as chickadees called more in response to conspecific mobbing calls, but not in response to heterospecific calls. General movement activity decreased in response to playback of conspecific-produced vocalizations, but increased in response to heterospecific-produced vocalizations, suggesting that chickadees may mobilize more in response to predator playback in preparation for a “fight or flight” situation. These results also suggest that chickadees may produce more mobbing calls in response to high-threat predator vocalizations as an attempt to initiate mobbing with conspecifics, while they produce fewer mobbing calls in response to a low-threat predator that a chickadee could outmaneuver.
No related grants have been discovered for Neil McMillan.