Behavioural Processes 115 (2015) 25–29 Contents lists available at ScienceDirect Behavioural Processes jo ur nal homep ag e: www.elsevier.com/locate/behavproc Cue-based and algorithmic learning in common carp: A possible link to stress coping style Flavia Oliveira Mesquita, Fabio Luiz Borcato, Felicity Ann Huntingford ∗ Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK a r t i c l e i n f o Article history: Received 16 November 2014 Received in revised form 22 February 2015 Accepted 23 February 2015 Available online 25 February 2015 Keywords: Common carp Association learning Cyprinus carpio Routine formation Personality Stress coping style a b s t r a c t Common carp that had been screened for stress coping style using a standard behavioural test (response to a novel environment) were given a learning task in which food was concealed in one of two compartments, its location randomised between trials and its presence in a given compartment signalled by either a red or a yellow light. All the fish learned to find food quickly, but did so in different ways. Fifty five percent learned to use the light cue to locate food; the remainder achieved the same result by developing a fixed movement routine. To explore this variation, we related learning strategy to stress coping style. Time to find food fell identically with successive trials in carp classified as reactive or proactive, but reactive fish tended to follow the light cue and proactive fish to adopt a fixed routine. Among fish that learned to follow the light, reactive individuals took fewer trials to reach the learning criterion than did proactive fish. These results add to the growing body of information on within-species variation in learning strategies and suggest a possible influence of stress coping style on the use of associative learning as opposed to algorithmic searching during foraging. © 2015 Elsevier B.V. All rights reserved. 1. Introduction There is increasing interest in the fact that cognitive traits may vary within species, as well as between them (e.g. Thornton and Lukas, 2012). For example, different patterns of learning among individuals of the same species have been documented in mam- mals (e.g. Guenther et al., 2013), birds (e.g. Guillette et al., 2011; Brust et al., 2013), reptiles (e.g. Carazo et al., 2014) and fish (e.g. Sneddon, 2003; Overli et al., 2007). There is also increasing inter- est in understanding the causes and consequences of such variation and it has been suggested that one influential factor may be what is sometimes referred to as stress coping style or animal personality (e.g. Carrere and Locuto, 2011; Sih and Del Guidice, 2012). The extensive literature on stress coping styles in animals shows that in many species of vertebrate, including mammals (Koolhaas et al., 2010), birds (Van Oers and Naguib, 2013) and fish (Moretz et al., 2007), and some invertebrates (Mather and Logue, 2013), individuals differ consistently in how they respond, behaviourally ∗ Corresponding author. Tel.: +44 1419450404; fax: +44 141 330 5971. E-mail address: Felicity.Huntingford@glasgow.ac.uk (F.A. Huntingford). and physiologically, to a variety of challenges. In other words, they show different stress coping styles, with individuals lying at differ- ent points along a proactive–reactive axis (Carere and Maestripieri, 2013). At one extreme, proactive individuals react positively to challenge, tend to take risks, show relatively high levels of aggression and readily form behavioural routines. Physiologically, challenges induce predominantly adrenaline-based responses. At the other extreme, reactive individuals avoid risk and conflict, respond to challenge by freezing or hiding, are behaviourally flex- ible and show a predominantly cortisol-based physiological stress response (review: Caramaschi et al., 2013). In a discussion of potential links between stress coping style, learning and cognition, Sih and Del Guidice (2012) point out that an animal’s behavioural type may determine the probability that it encounters a learning situation (e.g. bold, proactive animals may simply find themselves exposed to a learning task quicker than do reactive, shy ones), how it processes information once in the learning situation (e.g. proactive animals are often relatively insensitive to new information) and whether and how it uses this information to produce learned behavioural changes. Sih and Del Guidoce (2012) predict a number of differences in cognitive pro- cesses between proactive and reactive animals, based on a trade-off http://dx.doi.org/10.1016/j.beproc.2015.02.017 0376-6357/© 2015 Elsevier B.V. All rights reserved.