As electronic supplementary material, table S2 shows, these sequences started between 0 and 4 trials from the first exposure to the task.
Once a bird retrieved the reward consistently in 20 consecutive successful trials, we examined parameters of their behaviour along these trials. Inter-rater reliability was excellent (intraclass coefficient = 0.999 F = 3209 p < 0.001). Twenty per cent of the data was doubly scored (S.B. Hence, we scored the time from first touching the material to food retrieval. This separation was not possible for the TW as subjects repeatedly modified the partly inserted material. Manipulation time could be split into manufacture time and tool use time for LW and CB. In successful trials, we scored the length and number of pieces used to touch the apparatus and scored manipulation time from the video files.
Preparing goffin cockatoo trial#
To establish if the birds could actively produce an elongated shape, we confronted the four tool-using birds with materials that required direct shaping owing to the absence of pre-existing structures, or that needed completely different manipulation patterns.Įach trial was classified as success or failure. slim enough to fit through the grid and long enough to reach the target) the animals might, for example, have bitten and torn the material out at random places, accidentally producing splinters that served as elongated, functional tools. Although the tools were of sufficient length and shape (i.e.
As the material breaks more easily along the age lines of the tree, it was unclear whether the elongated shape of the tools they made was accidental.
The substrate used in those experiments was larch wood. One did so spontaneously and the other after one tool-making demonstration. Two later succeeded in making their own tools out of the same material (larch wood). In a follow-up study, three males were able to emulate Figaro's tool use after receiving tool use (not manufacture) demonstrations. As he took approximately four times as long to make his first tool as for any subsequent tool it is likely that we recorded his original innovation event. In a set of 10 observations, Figaro showed nine instances of tool making, one involving a different substrate (snipping of a branch from a leafless twig). Research into Goffin's cockatoos' tool behaviour started after a captive male named Figaro spontaneously and reliably manufactured tools by cutting splinters out of larch wood, using them to rake in food placed behind the aviary grid. Their tool-related competence in the laboratory offers a valuable opportunity to isolate events of individual innovation. This suggests that tool related behaviours in this species are unlikely to express heritable predispositions for tool use, tool making or nest building as is the case in some corvids. Huber, unpublished data, ongoing fieldwork). Goffin's cockatoos do not build nests, nor are they known to be specialized for using foraging tools in the wild ( M. Here we focus on the manufacture of stick-type tools in the Goffin's cockatoo ( Cacatua goffiniana) across a variety of materials. For instance, the degree of flexibility shown by members of a species in making differently shaped tools, engaging in different manufacturing techniques and using different materials gives a measure of the relative contributions of heritable competence, individually and/or socially acquired skills and occurrences of true individual creativity ( for summaries). Animal tool use is a target of concerted research effort owing to its potential for revealing cognitive capabilities.
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