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Irene M. Pepperberg - One of the best experts on this subject based on the ideXlab platform.

  • Piagetian liquid overconservation in grey parrots (Psittacus Erithacus).
    Journal of comparative psychology (Washington D.C. : 1983), 2019
    Co-Authors: Francesca M Cornero, Leigh Ann Hartsfield, Irene M. Pepperberg
    Abstract:

    Piagetian liquid overconservation was investigated in four grey parrots (Psittacus Erithacus). Birds tracked the larger of two quantities that had undergone various manipulations. Experiment 1 involved controls to ensure birds could track movement of the quantities, including direct and diagonal cross-transfers. All birds succeeded. In Experiment 2, different amounts in the same transparent or opaque containers were transferred into containers rigged such that amounts then looked equal. All birds chose the larger amounts after transformation when initial cups were transparent, but were random or had consistent side preferences when initial cups were opaque (thus obscuring quantity differences), showing that they used inferential, not perceptual, information, and that no extraneous cues existed. In Experiment 3, two birds saw different amounts from same-sized transparent or opaque containers transferred to containers of different sizes, rigged such that resultant amounts appeared to fill both cups and in which lesser amounts appeared greater on some trials. The older bird demonstrated full use of inferential abilities; he succeeded in all tasks when initial cups were transparent but, again, had consistent side preferences with initially opaque cups. The younger succeeded in the direct transfers with transparent initial cups but was random or showed a side preference on diagonal-transfer tasks and on all the tasks with opaque initial cups. However, she had no preference for the cup that appeared fuller, suggesting she did not use perceptual cues. Overall, grey parrots appear to understand the constancy of liquids undergoing physical transformation. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

  • piagetian liquid conservation in grey parrots psittacus Erithacus
    Journal of Comparative Psychology, 2017
    Co-Authors: Irene M. Pepperberg, Suzanne L Gray, Justin S Lesser, Leigh Ann Hartsfield
    Abstract:

    Piagetian liquid overconservation was investigated in four grey parrots (Psittacus Erithacus). Birds tracked the larger of two quantities that had undergone various manipulations. Experiment 1 involved controls to ensure birds could track movement of the quantities, including direct and diagonal cross-transfers. All birds succeeded. In Experiment 2, different amounts in the same transparent or opaque containers were transferred into containers rigged such that amounts then looked equal. All birds chose the larger amounts after transformation when initial cups were transparent, but were random or had consistent side preferences when initial cups were opaque (thus obscuring quantity differences), showing that they used inferential, not perceptual, information, and that no extraneous cues existed. In Experiment 3, two birds saw different amounts from same-sized transparent or opaque containers transferred to containers of different sizes, rigged such that resultant amounts appeared to fill both cups and in which lesser amounts appeared greater on some trials. The older bird demonstrated full use of inferential abilities; he succeeded in all tasks when initial cups were transparent but, again, had consistent side preferences with initially opaque cups. The younger succeeded in the direct transfers with transparent initial cups but was random or showed a side preference on diagonal-transfer tasks and on all the tasks with opaque initial cups. However, she had no preference for the cup that appeared fuller, suggesting she did not use perceptual cues. Overall, grey parrots appear to understand the constancy of liquids undergoing physical transformation. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

  • chapter 3 numerical concepts grey parrot capacities
    Mathematical Cognition and Learning, 2015
    Co-Authors: Irene M. Pepperberg
    Abstract:

    Do humans and nonhumans share the ability to form abstract concepts, particularly with respect to number? Until the 1960s, many researchers questioned whether avian subjects could form categorical constructs, much less more abstract formulations, including concepts such as same-different or exact understanding of number. Here, I review research on numerical concepts in the Grey parrot (Psittacus Erithacus), demonstrating that at least one subject, Alex, understood number symbols as abstract representations of real-world collections, in ways comparing favorably to those of apes and young human children. He also appeared to learn numerical concepts in ways more similar to those of humans than to apes.

  • creativity and innovation in the grey parrot psittacus Erithacus
    Animal Creativity and Innovation, 2015
    Co-Authors: Irene M. Pepperberg
    Abstract:

    Grey parrots are known to have communication skills roughly comparable to a 1.5–2 year old human child and the intellectual capacities of a 5–6 year old child, but little has been reported regarding other aspects of their cognitive and communicative abilities: in particular, creativity and innovation. This chapter thus centers on Grey parrot vocal and cognitive creativity and innovation: how these birds learn, adapt, and transfer their knowledge of speech and concepts across various cognitive domains.

  • reasoning by inference further studies on exclusion in grey parrots psittacus Erithacus
    Journal of Comparative Psychology, 2013
    Co-Authors: Irene M. Pepperberg, Adrienne Koepke, Paige Livingston, Monique Girard, Leigh Ann Hartsfield
    Abstract:

    Grey parrot (Psittacus Erithacus) abilities for visual inferential reasoning by exclusion were tested in two experiments. The first replicated the Grey parrot study of Mikolasch, Kotrschal, and Schloegl (2011, African Grey Parrots (Psittacus Erithacus) use inference by exclusion to find hidden food. Biology Letters, 7, 875-877), which in turn replicated that of Premack and Premck (1994, Levels of causal understanding in chimpanzees and children. Cognition, 50, 347-362) with apes, to learn if our subjects could succeed on this task. Here parrots watched an experimenter hide two equally desirable foods under two separate opaque cups, surreptitiously remove and then, in view of the birds, pocket/eat one of the foods, leaving birds to find the still baited cup. The experiment contained controls for various alternative explanations for the birds' behavior, but birds might still have avoided a cup from which something had been removed rather than specifically tracking the eaten food. Thus, in the second experiment, some trials were run with one food slightly more preferred than the other, during which two items of each type were hidden and only one of the items were removed from one cup. Sessions also included Experiment 1-type trials to see if birds tracked when and when not to use exclusion. Thus, birds would be rewarded for attending closely to all the experimental aspects needed to infer how to receive their preferred treat. Three of four birds succeeded fully.

Franz Schwarzenberger - One of the best experts on this subject based on the ideXlab platform.

  • Social isolation shortens telomeres in African Grey parrots (Psittacus Erithacus Erithacus).
    PloS one, 2014
    Co-Authors: Denise Aydinonat, Dustin J. Penn, Steve Smith, Yoshan Moodley, Franz Hoelzl, Felix Knauer, Franz Schwarzenberger
    Abstract:

    Telomeres, the caps of eukaryotic chromosomes, control chromosome stability and cellular senescence, but aging and exposure to chronic stress are suspected to cause attrition of telomere length. We investigated the effect of social isolation on telomere length in the highly social and intelligent African Grey parrot (Psittacus Erithacus Erithacus). Our study population consisted of single-housed (n = 26) and pair-housed (n = 19) captive individuals between 0.75 to 45 years of age. Relative telomere length of erythrocyte DNA was measured by quantitative real-time PCR. We found that telomere length declined with age (p

  • social isolation shortens telomeres in african grey parrots psittacus Erithacus Erithacus
    PLOS ONE, 2014
    Co-Authors: Denise Aydinonat, Dustin J. Penn, Steve Smith, Yoshan Moodley, Franz Hoelzl, Felix Knauer, Franz Schwarzenberger
    Abstract:

    Telomeres, the caps of eukaryotic chromosomes, control chromosome stability and cellular senescence, but aging and exposure to chronic stress are suspected to cause attrition of telomere length. We investigated the effect of social isolation on telomere length in the highly social and intelligent African Grey parrot (Psittacus Erithacus Erithacus). Our study population consisted of single-housed (n = 26) and pair-housed (n = 19) captive individuals between 0.75 to 45 years of age. Relative telomere length of erythrocyte DNA was measured by quantitative real-time PCR. We found that telomere length declined with age (p<0.001), and socially isolated parrots had significantly shorter telomeres compared to pair-housed birds (p<0.001) – even among birds of similar ages. Our findings provide the first evidence that social isolation affects telomere length, which supports the hypothesis that telomeres provide a biomarker indicating exposure to chronic stress.

Dalila Bovet - One of the best experts on this subject based on the ideXlab platform.

  • A Study of Sharing and Reciprocity in Grey Parrots (Psittacus Erithacus)
    Animal Cognition, 2012
    Co-Authors: Franck Péron, Dalila Bovet, Maria John, Stephanie Sapowicz, Irene M. Pepperberg
    Abstract:

    Demonstrations of nonhuman ability to share resources and reciprocate such sharing seem contingent upon the experimental paradigm used (note Horner et al. in PNAS 108:13847-13851, 2011). Here, such behaviour in Grey parrots (Psittacus Erithacus) was tested in two experiments, both designed to avoid possible issues involving apparatus complexity, visible reward options, and physical competition and/or limited communication between subjects.

  • Context-related vocalizations in African grey parrots (Psittacus Erithacus)
    acta ethologica, 2012
    Co-Authors: Nicolas Giret, Laurent Nagle, Michel Kreutzer, Aurélie Albert, Dalila Bovet
    Abstract:

    A few animal species are capable of vocal learning. Parrots are well known for their vocal imitation abilities. In this study, we investigated whether African grey parrots ( Psittacus Erithacus ) emit specific vocalizations in specific contexts. We first described the vocal repertoire and its ontogenesis of four captive grey parrots. After a comparison with vocalizations emitted by wild and other captive African grey parrots, we observed that only three call categories were shared by all grey parrots populations, suggesting that isolated populations of parrots develop population-specific calls. Then, we artificially provoked ten different contexts and recorded vocalizations of four captive grey parrots in these situations. Parrots predominantly emitted call categories in some contexts: distress, protestation, alarm, asking (i.e. emitted when a bird wanted something from an experimenter) and contact calls. These results suggest that some calls are learned and can be used in specific contexts.

  • Cooperative problem solving in African grey parrots ( Psittacus Erithacus )
    Animal Cognition, 2011
    Co-Authors: Franck Péron, Lauriane Rat-fischer, Mathilde Lalot, Laurent Nagle, Dalila Bovet
    Abstract:

    One of the main characteristics of human societies is the extensive degree of cooperation among individuals. Cooperation is an elaborate phenomenon, also found in non-human primates during laboratory studies and field observations of animal hunting behaviour, among other things. Some authors suggest that the pressures assumed to have favoured the emergence of social intelligence in primates are similar to those that may have permitted the emergence of complex cognitive abilities in some bird species such as corvids and psittacids. In the wild, parrots show cooperative behaviours such as bi-parental care and mobbing. In this study, we tested cooperative problem solving in African grey parrots (Psittacus Erithacus). Our birds were tested using several experimental setups to explore the different levels of behavioural organisation between participants, differing in temporal and spatial complexity. In our experiments, African grey parrots were able to act simultaneously but mostly failed during the delay task, maybe because of a lack of inhibitory motor response. Confronted with the possibility to adapt their behaviour to the presence or absence of a partner, they showed that they were able to coordinate their actions. They also collaborated, acting complementarily in order to solve tasks, but they were not able to place themselves in the partner’s role.

  • Conspecific discrimination in an object-choice task in African grey parrots (Psittacus Erithacus)
    Behavioural processes, 2009
    Co-Authors: Nicolas Giret, Michel Kreutzer, Marie Monbureau, Dalila Bovet
    Abstract:

    Living in social groups presents the opportunity to use information provided by other individuals. Several animal species emit specific vocalizations when they find food. Here, we investigate whether African grey parrots (Psittacus Erithacus) use vocal and non-vocal information provided by a conspecific in order to find a hidden food source. One subject was attracted by the presence or the vocalizations of a subordinate conspecific, but not of a dominant, which brings us to hypothesize that parrots could be capable of individual vocal discrimination.

Denise Aydinonat - One of the best experts on this subject based on the ideXlab platform.

  • Social isolation shortens telomeres in African Grey parrots (Psittacus Erithacus Erithacus).
    PloS one, 2014
    Co-Authors: Denise Aydinonat, Dustin J. Penn, Steve Smith, Yoshan Moodley, Franz Hoelzl, Felix Knauer, Franz Schwarzenberger
    Abstract:

    Telomeres, the caps of eukaryotic chromosomes, control chromosome stability and cellular senescence, but aging and exposure to chronic stress are suspected to cause attrition of telomere length. We investigated the effect of social isolation on telomere length in the highly social and intelligent African Grey parrot (Psittacus Erithacus Erithacus). Our study population consisted of single-housed (n = 26) and pair-housed (n = 19) captive individuals between 0.75 to 45 years of age. Relative telomere length of erythrocyte DNA was measured by quantitative real-time PCR. We found that telomere length declined with age (p

  • social isolation shortens telomeres in african grey parrots psittacus Erithacus Erithacus
    PLOS ONE, 2014
    Co-Authors: Denise Aydinonat, Dustin J. Penn, Steve Smith, Yoshan Moodley, Franz Hoelzl, Felix Knauer, Franz Schwarzenberger
    Abstract:

    Telomeres, the caps of eukaryotic chromosomes, control chromosome stability and cellular senescence, but aging and exposure to chronic stress are suspected to cause attrition of telomere length. We investigated the effect of social isolation on telomere length in the highly social and intelligent African Grey parrot (Psittacus Erithacus Erithacus). Our study population consisted of single-housed (n = 26) and pair-housed (n = 19) captive individuals between 0.75 to 45 years of age. Relative telomere length of erythrocyte DNA was measured by quantitative real-time PCR. We found that telomere length declined with age (p<0.001), and socially isolated parrots had significantly shorter telomeres compared to pair-housed birds (p<0.001) – even among birds of similar ages. Our findings provide the first evidence that social isolation affects telomere length, which supports the hypothesis that telomeres provide a biomarker indicating exposure to chronic stress.

Kemper, Jenny M. - One of the best experts on this subject based on the ideXlab platform.