Question · Cognition

Do Ravens Use Tools? What the Evidence Actually Shows

[science] Ravens demonstrate limited tool use in controlled experiments — string-pulling, stone-using — and extensive object manipulation, but they are not systematic tool users like New Caledonian crows. Their cognitive strength lies in social intelligence and planning rather than physical tool construction. What ravens do with objects reflects high exploratory drive and flexibility, not a specialised tool-use module.

What Counts as Tool Use?

[science] Animal cognition researchers define tool use as: using an external object to modify the form, position, or condition of another object, the tool user itself, or another organism, to achieve an immediate goal. By this definition, tool use requires the object to be held or manipulated during use — not merely displacing food by rolling a stone onto it accidentally. Ravens have been documented meeting this definition in several laboratory contexts, though not consistently in the wild.¹

Documented Tool Use in Ravens

[science] Evidence for raven tool use comes primarily from controlled captive studies:¹²

String-pulling: Ravens have learned to pull a string attached to a food reward — stepping on the string with one foot and pulling with the bill to gradually retrieve food hanging below a perch. This requires sequential, coordinated action, and ravens often solve it on the first attempt after a brief observation period, suggesting insight rather than trial-and-error learning.
Stone use in captivity: Some captive ravens use stones or hard objects to break open eggs or hard food items, holding the stone while striking — meeting the strict definition of tool use. This behaviour is not consistently reported in wild populations.
Stick manipulation: Ravens will probe with sticks in captive tests, though this is less systematic than the elaborate stick-tool manufacture shown by New Caledonian crows.

A key point: ravens often show the cognitive capacity to solve tool problems when necessary without having evolved tool use as a routine foraging strategy. Their varied, opportunistic diet means tools rarely provide efficiency gains that would drive selection for tool use.

Ravens vs. New Caledonian Crows

[science] New Caledonian crows (Corvus moneduloides) are the most sophisticated bird tool users known. The comparison with ravens is instructive:¹

New Caledonian crows: manufacture hooked tools from Pandanus leaf edges; fabricate step-cut tools; transmit tool designs socially across generations; use tools as a primary foraging strategy for extracting invertebrates from bark and soil.
Common Ravens: can solve tool tasks when presented with them; show high object manipulation drive; but do not routinely manufacture or deploy tools in the wild. In direct comparisons, ravens perform worse on tool-use tasks but better on some social cognition tasks (such as tracking what another individual knows or has seen).

Both species have large brains relative to body size, but their cognitive specialisations differ: New Caledonian crows in physical problem-solving, Common Ravens in social and planning tasks.

Object Play as Cognitive Foundation

[science] Ravens engage in extensive object play — carrying, dropping, and manipulating objects far beyond any foraging purpose. Researchers including Stahler et al. and Heinrich have argued that this exploratory behaviour may represent the cognitive substrate from which more systematic tool use could emerge under appropriate ecological selection pressure.² Object play in young ravens involves:

Picking up novel objects and flying with them (sometimes dropping and catching in flight).
Caching and retrieving objects with no food value.
Trading objects with other ravens in apparent social play contexts.

The flexibility shown in object play — trying objects in different orientations and contexts — is consistent with the generalised problem-solving capacity that makes ravens cognitively impressive even without systematic tool use.

Frequently Asked Questions

Do ravens use tools in the wild?

Documented tool use by wild Common Ravens is rare and limited. Unlike New Caledonian crows, ravens do not routinely manufacture or deploy tools for foraging. What ravens do show is extensive object manipulation — using their bill to lever, pry, and probe in ways that parallel tool use. In captivity, ravens have solved multi-step tool-use tasks (pulling string to retrieve food, using stones to break open hard food items), suggesting the cognitive capacity exists but is rarely deployed in wild conditions where it is not necessary.

Are ravens better at using tools than crows?

No — crows (particularly New Caledonian crows, Corvus moneduloides) are significantly more consistent tool users than ravens. New Caledonian crows manufacture hooked tools from leaves and twigs to extract insects from bark, and wild juveniles learn tool-use techniques through social transmission. Common Ravens have greater cognitive flexibility in social and future-planning tasks, but their physical tool use is less developed. Both species are significantly more capable than most birds, but in different cognitive domains.

What objects do ravens manipulate?

Ravens manipulate a wide range of objects in both play and apparent problem-solving: sticks, stones, pieces of metal, food containers, and novel objects encountered in their environment. Object manipulation in ravens is closely linked to play behaviour — ravens will carry, drop, and fiddle with objects for extended periods in what appears to be exploration. Some researchers argue that object play in ravens may be the foundation from which tool-use cognition could develop, even if it has not resulted in systematic tool use in this species.

Sources

Bugnyar, T. & Heinrich, B. (2005). Ravens, Corvus corax, differentiate between knowledgeable and ignorant competitors. Proceedings of the Royal Society B, 272(1573), 1641–1646. — object manipulation, tool-task performance, social cognition comparison with New Caledonian crows.
Heinrich, B. (1999). Mind of the Raven: Investigations and Adventures with Wolf-Birds. Cliff Street Books. — string-pulling, object play, stone use, wild versus captive tool behaviour.

[science] peer-reviewed data