Behavioural innovations with tool-like objects in non-habitually tool-using species are thought to require complex physical understanding, but the underlying cognitive processes remain poorly understood. A few parrot species are capable of innovating tool-use and borderline tool-use behaviours. We tested this capacity in two species of macaw (Ara ambiguus, n = 9; Ara glaucogularis, n = 8) to investigate if they could solve a problem-solving task through manufacture of a multi-stone construction. Specifically, after having functional experience with a pre-inserted stick tool to push a reward out of a horizontal tube, the subjects were required to insert five stones consecutively from one side to perform the same function as the stick tool with the resulting multi-component construction. One Ara glaucogularis solved the task and innovated the stone construction after the experience with the stick tool. Two more subjects (one of each species) did so after having further functional experience of a single stone pushing a reward out of a shortened tube. These subjects were able to consistently solve the task, but often made errors, for example counter-productive stone insertions from the opposing end, even in some of the successful trials. Conversely, multiple trials without errors also suggested a strong goal direction. Their performance in the follow-up tasks was inconclusive since they sometimes inserted stones into un-baited or blocked ‘dummy tubes’, but this could have been an attention-deficit behaviour as subjects had not encountered these ‘dummy tubes’ before. Overall, the successful subjects’ performance was so erratic that it proved difficult to conclude whether they had functional understanding of their multi-stone constructions.

人们认为，在非习惯性使用工具的物种中使用类似工具的物体的行为创新需要复杂的物理理解，但其潜在的认知过程仍然知之甚少。少数鹦鹉能够革新工具使用和临界工具使用的行为。我们在两种金刚鹦鹉（Ara ambiguus，n = 9; Ara glaucogularis）中测试了这种能力，n = 8），研究他们是否可以通过制造多石结构来解决问题。具体来说，在具备使用预插入的棒状工具将奖励从水平管中推出的功能经验之后，要求受试者从一侧连续插入五块石头，以执行与棒状工具相同的功能，并得到多组件施工。一个阿糖胞苷glaucogularis通过使用棒状工具的经验，解决了任务并革新了石材的结构。在获得了另一块石头的功能经验后，又有另外两名受试者（每个物种中的一个）这样做了。这些受试者能够始终如一地解决任务，但经常犯错误，例如从相对端插入适得其反的结石，即使在某些成功的试验中也是如此。相反，多次尝试都没有错误也表明了强有力的目标方向。他们在后续任务中的表现尚无定论，因为他们有时将结石插入没有诱饵或阻塞的“虚拟管”中，但这可能是一种注意力不足的行为，因为受试者之前从未遇到过这些“虚拟管”。总体，