Cognition in the barn: range use and its relation to cognitive performance in free-range broiler chickens (Gallus gallus domesticus)

International audienceFree-range chickens are not all the same. Within the same group, under the same conditions, some individuals explore the range more than others. In many animal species, including chickens, individuals differ in behavior and cognition, i.e., how they perceive, process, and memorize information from their environment. We aimed to further understand the relationship between range use, spatial and non-spatial memory, and inhibitory control in two groups of free-range broiler chickens: those who frequently explore the range (‘high rangers, HR’) and those who prefer to stay in or near the barn (‘low rangers, LR’). Experiments were conducted on two flocks of broiler chickens (n=200 per flock) reared in similar conditions. To test spatial and non-spatial memory, an arena with 8 cups was used. During the training phase, individuals (nLR = 20, nHR = 21) learned that only a white cup among seven black cups was baited. To find the target cup, individuals could rely either on their spatial memory (the position of the cup in relation to the cues on the arena’s walls), or rely on their non-spatial memory (the color of the cup). Two probe tests, on two different days, for spatial memory (all cups are black) and non-spatial memory (the white cup changed its previous position) revealed that LR were quicker to visit the target cup during the spatial memory compared to HR (LR: 60.47 ± 44.58 s, HR: 80.60 ± 47.15 s; ranging level: t = − 2.21, p = 0.03; observation day: t = 0.36, p = 0.71). No differences between groups were found for non-spatial memory (Day 1: U = 195, p = 0.70, Day 2: U = 199, p = 0.77). To test inhibitory control, individuals (nLR = 7, nHR = 8) learned to detour either side of an opaque cylinder to gain a food reward. In the test condition, chickens were presented with a transparent cylinder in ten trials. As a sign of inhibition, subjects needed to refrain from trying to reach the food reward through the walls of the cylinder and detour to its open sides. LR were significantly more successful than HR (LR: 40 ± 12.90%, HR: 23.75 ± 9.16%, p = 0.028). Overall, our results show that LR chickens perform better in cognitive tasks compared to HR chickens. These results contribute to the growing body of research into the behavior and cognition of free-range chickens. This knowledge is essential for, ultimately, applying husbandry procedures that increase range use for all animals

Social motivation and the use of distal, but not local, featural cues are related to ranging behavior in free-range chickens (Gallus gallus domesticus)

International audienceAnimals can navigate an environment relying on different sources of information, such as geometrical or featural cues. The favoring of one type of information over another depends on multiple factors, such as inter-individual differences in behavior and cognition. Free-range chickens present different range use patterns, which may be explained by behavioral and cognitive differences. However, how behavior, cognition, and range use intercorrelate is still poorly understood. In this work, we aimed to further understand possible differences in behavior and cognition between two groups of free-range broiler chickens: those who frequently explore their range ('high rangers') and those who prefer to stay in or near the barn ('low rangers'). Prior to range access, individual behavior was measured in open field-, emergence-, and social motivation tests. To investigate cognitive differences, we analyzed whether exploratory behavior was linked to different performances in the use of distal and local spatial cues during an orientation task. During the social motivation test, low rangers showed a higher inclination to be near conspecifics than did high rangers. Our orientation tests show that chickens preferred to orientate themselves using the local cues over the distal cues. Individual differences were only found for distal, but not for local, cue use suggesting that demanding tasks are more efficient in revealing individual cognitive differences. Our results suggest that considering variation in social motivation may allow a more comprehensive understanding of chicken range use. Our results also support the importance of incorporating multiple aspects of individual differences to understand individual reactions to its environment