Data from: DNA barcoding identifies cryptic animal tool materials

Some animals fashion tools and other constructions out of plant materials
to aid foraging, reproduction, self-maintenance, and protection. The
choice of raw materials can affect the structure and mechanical properties
of the resulting artefacts, with significant fitness consequences.
Documenting animals’ material preferences is challenging, however, as
manufacture behaviour is often difficult to observe directly, and
materials may be processed so heavily that they lack identifying features.
Here, we use DNA barcoding techniques to identify, from just a few
recovered tool specimens, the plant species New Caledonian crows (Corvus
moneduloides) use for crafting elaborate hooked stick tools in one of our
long-term study populations. The method succeeded where extensive
fieldwork using conventional approaches had failed, including targeted
observations, radio-tracking, bird-mounted video-cameras, and behavioural
experiments with wild and temporarily captive subjects. We believe that
DNA barcoding will prove useful for investigating many other tool and
construction behaviours, helping to unlock significant research potential
across a wide range of study systems.