Wild American crows use funerals to learn about danger

University of Washington Abstract Wild American crows use funerals to learn about danger Kaeli Swift Chair of Supervisory Committee: Dr. John Marzluff School of Environmental and Forest Sciences While a growing number of animals demonstrate seemingly ritualistic behaviors around the death or body of a conspecific, the evolutionary basis for this behavior remains unclear. Here we demonstrate that wild American crows (Corvus brachyrhynchos) are using funeral gatherings as an opportunity to engage in social learning, inform future resource use, infer novel predators, and that this behavior is not shared by another urban bird: the rock pigeon (Columba livia). Novel humans paired with a dead crow, a red-tailed hawk (Buteo jamaicensis), and a hawk with a dead crow all evoked mobbing and decreased foraging by crows, while pairing with a dead pigeon did not. These findings suggest that dead conspecifics, but not heterospecifics, represent a salient danger akin to observation of a predator. Mobbing and decreased foraging immediately after stimulus removal were strongest when crows were presented a hawk with a dead crow. Over the next 3 d we found that crows avoided food in areas associated with these dangerous events. However, site avoidance was uniform across stimuli suggesting that crow sensitivity to the identity of the threat dissipates after 24 h. In addition, we demonstrated that crows use proximity to predators, dead conspecifics and predators with conspecific remains as a cue to learn and subsequently scold the associated human after only 1 training event, and that this association could last 6 weeks. Together, these data provide important insights into the nature of crow funeral gatherings and how crows navigate the threatening landscape.

Author dc:creator

• Swift, Kaeli N.

Advisor dc:contributor.advisor

• Marzluff, John M

• American crow; conditioned learning; fear extinction; response to dead conspecific; response to dead heterospecific; rock pigeon

Statement dc:rights

• Copyright is held by the individual authors.

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/1773/33178

OAI identifier oai:identifier

oai:digital.lib.washington.edu:1773/33178