Odour Learning Bees Have Longer Foraging Careers Than Non-learners in a Natural Environment

Abstract

Individual animals allowed the opportunity to learn generally outperform those prevented from learning, yet, within a species the capacity for learning varies markedly. The evolutionary processes that maintain this variation in learning ability are not yet well understood. Several studies demonstrate links between fitness traits and visual learning, but the selection pressures operating on cognitive traits are likely influenced by multiple sensory modalities. In addition to vision, most animals will use a combination of hearing, olfaction (smell), gustation (taste), and touch to gain information about their environment. Some animals demonstrate individual preference for, or enhanced learning performance using certain senses in relation to particular aspects of their behaviour (e.g., foraging), whereas conspecific individuals may show different preferences. By assessing fitness traits in relation to different sensory modalities we will strengthen our understanding of factors driving observed variation in learning ability. We assessed the relationship between the olfactory learning ability of bumble bees (Bombus terrestris) and their foraging performance in their natural environment. We found that bees which failed to learn this odour-reward association had shorter foraging careers; foraging for fewer days and thus provisioning their colonies with fewer resources. This was not due to a reduced propensity to forage, but may have been due to a reduced ability to return to their colony. When comparing among only individuals that did learn, we found that the rate at which floral resources were collected was similar, regardless of how they performed in the olfactory learning task. Our results demonstrate that an ability to learn olfactory cues can have a positive impact of the foraging performance of B. terrestris in a natural environment, but echo findings of earlier studies on visual learning, which suggest that enhanced learning is not necessarily beneficial for bee foragers provisioning their colony.

Acute and chronic toxicity of imidacloprid in the pollinator fly, Eristalis tenax

“…Feeding behaviour in our experiments can be split into localising and navigating to the food source and extracting the food from the capillary. In bees, locating food sources is typically improved by associating odours, colours, and landmark features to rewarding sites in a cognitive process which relies on an imperfect daily memory (Keasar et al, 1996; Raine et al, 2006; Evans et al, 2021). The motor skills required to extract food from a rewarding site can also be learnt and improved over time (Raine and Chittka, 2007).…”

Contrasting effects of fungicide and herbicide active ingredients and their formulations on bumblebee learning and behaviour

“…Learning ability is key to bumblebee behaviour and their ultimate survival, as it allows bees to forage efficiently ( Raine and Chittka, 2008 ) and is related to the length of their foraging career ( Evans et al, 2021 ), amongst other tasks. If bumblebee learning is impaired after pesticide exposure, it is possible it may affect their ability to gather food resources for their colony or even return to their colony, with implications for colony fitness.…”

Divergent Circadian Foraging Strategies in Response to Diurnal Predation Versus Persistent Rain in Asian Weaver Ant, Oecophylla smaragdina, Suggest Possible Energetic Trade-offs

“…Ant workers often exit and enter the nest during foraging throughout day and night in shifts and at different intensities. Although ant nests usually have many active outlets (Pinter-Wollman et al, 2012), they are likely to reside in a communal setting and exhibit spatial foraging fidelity (Crall et al, 2018), so workers are more likely to drive some nestmates to commence foraging by biasing access to spatially localized nest information (Evans et al, 2021). It has been shown that workers exhibit remarkable repeatability in their spatial fidelity patterns across individual days, with workers returning to the same spatial zones within the nest in predictable patterns on successive days (Crall et al, 2018; Hanisch et al, 2023).…”