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Wild jackdaws are wary of objects that violate expectations of animacy.

Published version
Peer-reviewed

Type

Article

Change log

Authors

McIvor, Guillam E 
Thornton, Alex 

Abstract

Nature is composed of self-propelled, animate agents and inanimate objects. Laboratory studies have shown that human infants and a few species discriminate between animate and inanimate objects. This ability is assumed to have evolved to support social cognition and filial imprinting, but its ecological role for wild animals has never been examined. An alternative, functional explanation is that discriminating stimuli based on their potential for animacy helps animals distinguish between harmless and threatening stimuli. Using remote-controlled experimental stimulus presentations, we tested if wild jackdaws (Corvus monedula) respond fearfully to stimuli that violate expectations for movement. Breeding pairs (N = 27) were presented at their nests with moving and non-moving models of ecologically relevant stimuli (birds, snakes and sticks) that differed in threat level and propensity for independent motion. Jackdaws were startled by movement regardless of stimulus type and produced more alarm calls when faced with animate objects. However, they delayed longest in entering their nest-box after encountering a stimulus that should not move independently, suggesting they recognized the movement as unexpected. How jackdaws develop expectations about object movement is not clear, but our results suggest that discriminating between animate and inanimate stimuli may trigger information gathering about potential threats.

Description

Keywords

animacy categories, corvid, field experiment, inanimate object, threat assessment

Journal Title

R Soc Open Sci

Conference Name

Journal ISSN

2054-5703
2054-5703

Volume Title

5

Publisher

The Royal Society
Sponsorship
European Research Council (339993)
Biotechnology and Biological Sciences Research Council (BB/H021817/1)
Gates-Cambridge Trust studentship and a Cambridge Philosophical Society Grant to AG, a BBSRC David Phillips Fellowship (BB/H021817/1; BB/H021817/2), and a British Ecological Society grant (2769/3464) to AT, and a European Research Council grant under the European Union’s Seventh Framework Programme (FP7/2007–2013/ERC Grant Agreement No. 3399933) to NSC