The ecology of tool‐use in the woodpecker finch (Cactospiza pallida)

Abstract

Insects, mammals and birds are known to use tools, but empirical evidence of the ecological importance of tool-use is scarce. Here, we present the first ecological study of tool-use by a bird species. Woodpecker finches use twigs or cactus spines to pry arthropods out of tree-holes. We compared tool-use during wet and dry seasons in two different vegetation zones: the Arid Zone and the humid Scalesia Zone. In the Scalesia Zone, where food was abundant and easily accessible, woodpecker finches rarely used tools. In contrast, in the Arid Zone, where food was limited and hard to access, they obtained half of their prey using tools during the dry season. Tool-use enabled the birds to reach particularly large and otherwise inaccessible prey hidden in tree-holes. Our data suggest that tool-use in the woodpecker finch has evolved in response to the dry and unpredictable conditions in the coastal zone of the Galápagos Islands.

Extreme binocular vision and a straight bill facilitate tool use in New Caledonian crows

“…In other words, it remains an open question whether ancestors of NC crows possessed morphological features that predisposed them to tool manufacture and use, or whether tool-use behaviour was expressed first due to unusual ecological opportunities, before exerting selection pressures that gradually shaped the species' visual system and bill morphology 6 . Evidence that unusual ecological conditions have been major drivers in the evolution of habitual tool use is provided by detailed analysis of the foraging ecology of wild NC crows 6,18,19 and woodpecker finches Cactospiza pallida 20 , and the experimental results for rooks (see above). These avian study systems promise valuable, phylogenetically independent comparisons with the hominin lineage, where the evolution of opposable thumbs and flexible wrists in humans has enabled precision pinching and unprecedented tool-handling capabilities [2][3][4]15,16,21 .…”

‘Captivity bias’ in animal tool use and its implications for the evolution of hominin technology

“…However, it should be clear from the foregoing that components of models that rely, even in part, on innate factors such as intelligence and manual dexterity [62] are insufficient to explain the differences between wild and captive tool-use behaviour. Extrinsic factors, whether social [65], behavioural [2] or ecological [66,67], are therefore essential to a complete explanation of how and why tool use develops. Although in a speculative form, the implications and relevance of the captivity bias effect could likely complement existing studies of technological development in each hominin species (and population within each species).…”

Ecological and social correlates of chimpanzee tool use

“…have also come to the forefront as prominent tool users. Woodpecker finches in the Galápagos Islands use twigs or cactus spines to pry arthropods from tree holes [20]. Tebbich et al [21] recently reported woodpecker finches using tools manufactured from barbed twigs of introduced blackberry bushes to extract prey from under the bark of a native tree species, demonstrating their abilities to modify tools in a flexible manner and exploit novel environmental opportunities.…”