Few avian species use tools in the wild. Yet, several birds build nests of great complexity and many aspects of tool use may also apply to nest building. It has long been hypothesised that tool use may select for specialised cognitive adaptations or even general cognitive skills. This might similarly pertain to species that build complex nests. In this study, we investigated the problem-solving capacity of a complex nest builder, a weaverbird species, in a foraging context that either required or did not require the use of tools. First, we tested the capacity of yellow-crowned bishops (Euplectes afer ssp. afer) to use a tool for retrieving an out-of-reach reward during three problem-solving tasks offering different nest/non-nest materials (Experiment 1). Next, subjects were confronted with two problem-solving tasks that required no tools (Experiment 2). No subject was able to use a tool in Experiment 1. However, 11 out of 12 subjects succeeded in using their beak in the first problem-solving task, and 9 in the second problem-solving task of Experiment 2. These results suggest that weaverbirds showed flexible problem-solving if the use of tools was not required.

很少有鸟类在野外使用工具。然而，有几只鸟筑巢非常复杂，工具使用的许多方面也可能适用于筑巢。长期以来，人们一直假设工具的使用可能会选择专门的认知适应甚至一般的认知技能。这可能同样适用于建造复杂巢穴的物种。在这项研究中，我们调查了复杂的筑巢者（一种织布鸟）在需要或不需要使用工具的觅食环境中解决问题的能力。首先，我们测试了黄冠主教（Euplectes afer ssp. afer) 在提供不同嵌套/非嵌套材料的三个问题解决任务中使用一种工具来检索超出范围的奖励（实验 1）。接下来，受试者面临两个不需要工具的问题解决任务（实验 2）。没有受试者在实验 1 中能够使用工具。 然而，12 名受试者中有 11 名在第一次解决问题任务中成功使用了喙，在实验 2 的第二次解决问题任务中成功使用了 9 名受试者。这些结果表明织布鸟如果不需要使用工具，则表现出灵活的解决问题的能力。