The role of beginner's luck in learning to prefer risky patches by socially foraging house sparrows

Abstract

Although there has been extensive research on the evolution of individual decision making under risk (when facing variable outcomes), little is known on how the evolution of such decision-making mechanisms has been shaped by social learning and exploitation. We presented socially foraging house sparrows with a choice between scattered feeding wells in which millet seeds were hidden under 2 types of colored sand: green sand offering ~80 seeds with a probability of 0.1 (high risk-high reward) and yellow sand offering 1 seed with certainty (low risk-low reward). Although the expected benefit of choosing variable wells was 8 times higher than that of choosing constant wells, only some sparrows developed a preference for variable wells, whereas others developed a significant preference for constant wells. We found that this dichotomy could be explained by stochastic individual differences in sampling success during foraging, rather than by social foraging strategies (active searching vs. joining others). Moreover, preference for variable or constant wells was related to the sparrows' success during searching, rather than during joining others or when picking exposed seeds (i.e., they learn when actively searching in the sand). Finally, although for many sparrows learning resulted in an apparently maladaptive risk aversion, group living still allowed them to enjoy profitable variable wells by occasionally joining variable-preferring sparrows.

A unified modelling approach for producer–scrounger games in complex ecological conditions

“…Most published accounts of individual use of tactics are compatible with our model's expectation (Barnard & Sibly, 1981;Beauchamp, 2001;Bicca-Marques & Garber, 2005;Coolen, 2002;Coolen et al, 2001;Giraldeau, Hogan, & Clinchy, 1990;Ha & Ha, 2003;Ilan, Katsnelson, Motro, Feldman, & Lotem, 2013;Koops & Giraldeau, 1996;Mathot & Giraldeau, 2008;M onus & Barta, 2008;Morand-Ferron, Varennes, et al, 2011;Morand-Ferron, Wu, et al, 2011). In a series of experiments with house sparrows, Barnard and Sibly (1981) reported that producers obtained 19.8e38.3% of their food by joining and that scroungers obtained 38.5e48.8% of their food by searching.…”

House sparrows’ (Passer domesticus) behaviour in a novel environment is modulated by social context and familiarity in a sex-specific manner

“…Some aggressive or dominant individuals could for example be perceived as a stressor for their group-mates, thus increasing alert time and neophobia in difficult situations [ 23 , 24 ], while other conspecifics could have the very opposite effect, decreasing neophobia and alert time [ 13 ]. This underlines a system of conspecific recognition and flexibility in behavioural responses that may be affected by differences in behavioural traits and experiences [ 25 , 26 ].…”

Task‐Dependent Differences in Learning by Subordinate and Dominant Wild Arabian Babblers

“…Nevertheless, even if learning is not transmitted socially, variable task‐dependent learning abilities in a group can generate a skill pool effect (Giraldeau ) that allows social foragers to exploit a greater variety of food resources by simply joining each other's food findings (Giraldeau & Lefebvre ; Ilan et al. ). Thus, by providing the first evidence for task‐dependent differences in learning abilities of new tasks between dominants and subordinates in a cooperative bird, our study also suggests an interesting cascading effect: different social ranks that display different cognitive strategies can increase the variety of skills that may be generated in the group, which may then contribute to the benefits of group‐living.…”