Brosche, Kimberly and Regolin, Lucia and Zazio, Agnese and Rugani, Rosa (2024) Absolutely relative chicks: individual strategy preferences in numerical discrimination in Gallus gallus. [Data Collection]
Collection description
When trained to discriminate between two numerosities, animals could employ either (a) an absolute or (b) a relative discrimination strategy. In absolute discrimination, a specific numerosity (e.g., 10) is chosen against other numerosities. Relative discrimination consists in selecting the higher (or the lower) numerosity in any pair. Humans and fish have been shown to preferentially adopt a relative strategy, while honeybees apply an absolute strategy. This study aims to identify the strategy (absolute vs. relative) 3-day-old chicks (Gallus gallus) spontaneously adopt. During rearing, 124 chicks were exposed to a numerical comparison (10 vs. 20) and learned that one numerosity (10) was associated with food (Sp). During testing, which consisted of a single 6-minute unrewarded trial, each chick was presented with Sp (10; absolute strategy) alongside an unfamiliar numerosity consistent with the relative strategy ( 5, the smaller one out of 5 vs. 10). We hypothesized that chicks would spend more time near the numerosity corresponding to their preferred strategy. Chicks did not show a significant preference for either strategy on a group level, regardless of whether the higher (Exp. 1 and 2) or the lower numerosity (Exp. 3) had been reinforced during rearing. Interestingly, chicks exhibited significant individual preferences for one or the other strategy that cannot be explained by the novelty of the stimuli (Exp. 4) or by the use of physical variables (Exp. 2). These findings suggest either that diversity of numerical discrimination strategies was evolutionary favorable in domestic chickens’ natural environments, or that, at this early stage of ontogeny, young chicks’ strategies are still highly variable and flexible.
10.25430/researchdata.cab.unipd.it.00001331
orcid.org/0000-0003-2809-8591
