Spontaneous use and modification of a feather as a tool in a captive common raven

Abstract

Here, we report an observation of a zoo‐housed common raven (Corvus corax) modifying and using a raven feather as a tool to access the food cache of her partner. We believe this record is of importance, as it represents one of the first cases of untrained common ravens spontaneously using and modifying a tool, and a rare example of a non‐human animal manufacturing a tool from a body part. This anecdotal observation suggests that tool use and tool modification may be present in the common raven behavioral repertoire in the foraging context; nevertheless, further investigations are needed to assess this possibility in more controlled settings as well as in the wild.

Evidence of tool use in a seabird?

“…Novel discoveries in the field of animal tool-use research often report similarly small numbers of observations (e.g. Breuer, Ndoundou-Hockemba, & Fishlock, 2005;Gallot & Gruber, 2019;Hirata, Myowa, & Matsuzawa, 1998;Rutz & Deans, 2018) so our paper is not an exception. Second, puffins mostly live on remote uninhabited islands, with only a handful of populations under frequent study by scientists, and even at these sites researchers usually only observe a very small proportion of the population (<1% in our case).…”

A genome‐wide investigation of adaptive signatures in protein‐coding genes related to tool behaviour in New Caledonian and Hawaiian crows

“…While some non‐tool‐using crow species can learn to use tools in captivity, usually after some training or facilitation (Bird & Emery, 2009; Gallot & Gruber, 2019; Kanai et al, 2014; Powell & Kelly, 1977), it was long thought that the New Caledonian crow is the only natural tool user within the genus. Recent work revealed, however, that the critically endangered Hawaiian crow ( C. hawaiiensis ), from Hawai‘i Island in the North Pacific, is also highly skilled at making and using tools (Klump et al, 2018; Rutz et al, 2016).…”

Tool use and tooling in ravens (Corvus corax): A review and novel observations

“…The few birds observed to use reaching tools did so to move targets closer to them (Shumaker et al, 2011). A captive raven similarly modified and used a feather to reach a cache in a crevice (Gallot & Gruber, 2019). This is dynamic allocentric tooling with high specificity (Table 1).…”

“…The above description of using a feather to reach a cache (Gallot & Gruber, 2019) can also be labelled as Insert and probe (Table 1). Both modes have similar form and function and are recognized as difficult to disambiguate (Gallot & Gruber, 2019;Shumaker et al, 2011). The ravens voluntarily participated in various cognitive tasks throughout this period and were habituated to experimental materials and our presence.…”

“…The above description of pushing a stick to dislodge a food item (see Figure 2; H. Osvath & K. Bobrowicz, in litt. ) can also be labelled as the highly similar Insert and probe mode (Table 1; Gallot & Gruber, 2019;Shumaker et al, 2011).…”