Cognitive abilities related to tool use in the woodpecker finch, <i>Cactospiza pallida</i>

Woodpecker finches are famous for their spontaneous tool use behaviour in the wild. They use twigs or cactus spines to pry arthropods out of crevices and use this ability more than any other tool-using species known. We experimentally investigated the cognitive abilities related to tool use. We chose three experimental designs that have been used to test several primate species (trap tube task and modification task) and New Caledonian crows (tool length task). One of six woodpecker finches was able to solve the trap tube task, and several individuals modified tools and chose twigs of appropriate length. Most subjects mastered these new tasks quickly, but we found no evidence that they were able to assess the problems in advance. These findings resemble those obtained for primates in these tasks.