Selective auditory grouping by zebra finches: testing the iambic–trochaic law

Animal science

Pauses enhance chunk recognition in song element strings by zebra finches

Animal science

Non-adjacent dependency learning in humans and other animals

International audienc

Auditory discrimination learning in zebra finches:effects of sex, early life conditions and stimulus characteristics

A meta-analysis was conducted to investigate whether sex differences, developmental history, stimulus number and/or characteristics affect the speed of auditory discrimination learning of zebra finches, Taeniopygia guttata, as tested in a Go/No-go task. Our results indicate that sex, early life conditions (brood size and juvenile body size), the number of stimuli, type of stimuli (constructed from zebra finch song elements or human speech syllables) and type of discrimination (based on phonetic characteristics or sequential structure of sounds) significantly influenced learning speed. Learning speed was faster if birds were female, reared in larger broods or were larger as juveniles. Greater numbers of stimuli and human speech-based stimuli were harder to learn than fewer stimuli and stimuli consisting of zebra finch song elements. Stimuli differing in phonetic characteristics were learned faster than those varying in structure. Additionally, there was some evidence of stable individual differences in performance across experiments. Our findings demonstrate that discrimination learning can be affected by factors that have been suspected to, but not yet definitively shown to, have impacts on learning. We suggest that examining the learning process itself in more detail by quantifying individual differences in learning strategies may provide more information on how various factors affect variation in learning abilities

Temporal modulation in speech, music, and animal vocal communication: evidence of conserved function

International audienc

Budgerigars and zebra finches differ in how they generalize in an artificial grammar learning experiment

The ability to abstract a regularity that underlies strings of sounds is a core mechanism of the language faculty but might not be specific to language learning or even to humans. It is unclear whether and to what extent nonhuman animals possess the ability to abstract regularities defining the relation among arbitrary auditory items in a string and to generalize this abstraction to strings of acoustically novel items. In this study we tested these abilities in a songbird (zebra finch) and a parrot species (budgerigar). Subjects were trained in a go/no-go design to discriminate between two sets of sound strings arranged in an XYX or an XXY structure. After this discrimination was acquired, each subject was tested with test strings that were structurally identical to the training strings but consisted of either new combinations of known elements or of novel elements belonging to other element categories. Both species learned to discriminate between the two stimulus sets. However, their responses to the test strings were strikingly different. Zebra finches categorized test stimuli with previously heard elements by the ordinal position that these elements occupied in the training strings, independent of string structure. In contrast, the budgerigars categorized both novel combinations of familiar elements as well as strings consisting of novel element types by their underlying structure. They thus abstracted the relation among items in the XYX and XXY structures, an ability similar to that shown by human infants and indicating a level of abstraction comparable to analogical reasoning

Phenotypic plasticity of avian social-learning strategies

Social learning, whereby animals learn from others, mediates the spread of information through social networks. To make this process adaptive, animals should be selective with respect to when and whom to copy. The cost of decision making can be curbed by cognitive biases favouring particular categories of individuals. Such model biases are well documented, but few, if any, experimental studies have addressed potential developmental causes of this variation. We therefore tested whether and how the postnatal environment affected social-learning preferences in a known social learner the zebra finch, Taeniopygia guttata. Birds from experimentally manipulated brood sizes, a treatment known to affect adult phenotypic quality in this species, were tested in an established observer–demonstrator paradigm. Naïve observers could watch unfamiliar same-sex conspecifics feed from differently coloured novel feeders. When subsequently allowed to choose between identical feeders, postnatal conditions (=rearing brood size) had strong effects on who copied whom in adulthood: males preferred the feeders of demonstrators from large brood sizes, females those of demonstrators from brood sizes matching their own, suggesting stratified information transfer within foraging groups. Our results demonstrate how individuals’ developmental history can explain substantial interindividual variation in model biases and ensuing structured information transfer within groups.

Primates watching primates watching primates: Why do we anthropomorphise?

Anthropomorphism is the attribution of human traits, capacities, or mental states to non-human animals. Numerous factors likely affect our tendency to anthropomorphise (TA). Previous studies, using questionnaire methods found increased TA with phylogenetic distance to other species, while empathy and compassion decreased. We used covert focal observations, typically used to quantify animal behavior, to collect visitor comments at primate enclosures in two European Zoos (Vienna, Nuremberg). We quantified TA as the relative frequency of anthropomorphic vs. non-anthropomorphic comments. We additionally collected questionnaire data to investigate how average perceived resemblance to humans and species aesthetic appeal mediate the relatedness effect on TA. Following our hypotheses, we expect TA to correlate negatively with phylogenetic distance, and positively with increased resemblance and aesthetic perception independently of phylogenetic distance. Using a novel approach, this study provides new insights into human perception of and emotional connection to non-human primates