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Species' cognitive traits are shaped by their ecology, and even within a species, cognition can reflect the behavioural requirements of individuals with different roles. Social insects have a number of discrete roles (castes) within a colony and thus offer a useful system to determine how ecological requirements shape cognition. Bumblebee queens are a critical point in the lifecycle of their colony, since its future success is reliant on a single individual's ability to learn about floral stimuli while finding a suitable nest site; thus, one might expect particularly adept learning capabilities at this stage. I compared wild Bombus vosnesenskii queens and workers on their ability to learn a colour association and found that queens performed better than workers. In addition, queens of another species, B. insularis, a cuckoo species with a different lifecycle but similar requirements at this stage, performed equally well as the non-parasitic queens. To control for differences in foraging experience, I then repeated this comparison with laboratory-based B. impatiens and found that unmated queens performed better than workers. These results add to the body of work on how ecology shapes cognition and opens the door to further research in comparative cognition using wild bees.

Bees are model organisms for the study of learning and memory, yet nearly all such research to date has used a single reward, nectar. Many bees collect both nectar (carbohydrates) and pollen (protein) on a single foraging bout, sometimes from different plant species. We tested whether individual bumblebees could learn colour associations with nectar and pollen rewards simultaneously in a foraging scenario where one floral type offered only nectar and the other only pollen. We found that bees readily learned multiple reward-colour associations, and when presented with novel floral targets generalized to colours similar to those trained for each reward type. These results expand the ecological significance of work on bee learning and raise new questions regarding the cognitive ecology of pollination., (© 2015 The Author(s).)

Bumblebees are important pollinators of agricultural crops and wildflowers, but many species are in decline. Neonicotinoid insecticides are the most commonly used insecticide globally and can have negative sublethal effects on bumblebee colony growth and reproduction. Individual bumblebees can visit hundreds to thousands of flowers a day to forage for their colony. As such, they are a model species for studying optimal foraging, and small impairments to an individual's foraging decisions may have compounding effects on the colony's nutritional intake. We exposed bumblebees (Bombus impatiens) to an acute, field-realistic dose of the neonicotinoid insecticide imidacloprid, before allowing them to forage on an artificial floral array. We found that neonicotinoid-exposed bumblebees made suboptimal foraging decisions, as they were more likely to visit flowers located further apart than control bees.This indicates that for a given flower patch, individual bees exposed to a neonicotinoid will likely use more energy and forage less efficiency than unexposed bees, although further studies that directly measure energetic cost are required to confirm this. Given the robust and growing body of evidence demonstrating negative sublethal effects of neonicotinoids on bees, sublethal assessments on non-Apis bees should be made mandatory within the regulatory process. [ABSTRACT FROM AUTHOR]

In their natural environments, most animals must learn about multiple kinds of rewards, both within and across contexts. Despite this, the majority of research on animal learning involves a single reward type. For example, bees are an important model system for the study of cognition and its ecological consequences, but nearly all research to date on their learning concerns a single reward, nectar (carbohydrates), even though foragers often simultaneously collect pollen (protein). Features of learning under more ecologically realistic conditions involving multiple reward types are thus largely unexplored. To address this gap, we compared performance on a colour-learning task when floral surrogates offered bumblebees, Bombus impatiens , a single type of floral reward versus multiple, nutritionally distinct rewards. In one experiment, bees learned a floral association with nectar either alone or while simultaneously collecting pollen. In a reciprocal experiment, bees learned a floral association with pollen either alone or while simultaneously collecting nectar. Bees that collected pollen while learning about nectar did not suffer any detriment to learning which flower colour offered nectar. However, this was not the case for the reciprocal task: collecting nectar impaired bees' ability to learn and remember associations between floral colour and pollen. Our findings offer new insight into how bees learn in relation to ecologically realistic rewards and how cognitive constraints may shape their behaviour under ecologically realistic foraging scenarios. [ABSTRACT FROM AUTHOR]

Ever since Karl von Frisch's Nobel Prize-winning work in the early 1900s, bees have served as an important model system for the study of learning, memory and foraging behaviour. Bees can learn about floral features including colour, scent, texture and electrostatic charge, and show surprisingly sophisticated forms of learning. However, nearly every study of bee cognition and foraging to date has used a sole reward: nectar, most often in the form of a simple sucrose solution. Plants also offer a number of other rewards to pollinators, the most prevalent being pollen that bees collect as their primary source of protein. Indeed, a significant proportion of angiosperm species are nectarless, rewarding bees with pollen alone. Surprisingly, whether free-flying bees can learn visual features based solely on floral pollen rewards is unknown. Here we show that bees can learn to associate multiple floral features with a pure pollen reward. Furthermore, these associations are remembered long term, comparable to bees' memory for nectar associations. These findings raise new questions about bee learning and the evolutionary history between plants and bee pollinators. [ABSTRACT FROM AUTHOR]

Stress has complex effects on learning and memory, depending on both the type of stress and when the animal experiences it. Honeybees and bumblebees are agriculturally important pollinators for whom the effects of stress are extremely relevant. These pollinators are often transported long distances during which colonies experience severe physical disturbance, causing stress to individuals prior to their release for pollination. Under natural foraging conditions, bees are excellent at learning about the flowers they forage from, including associations between floral stimuli and rewards. However, it is not clear how stress might affect bees’ abilities to learn and remember floral features. Here we address the effects of acute stress on learning and memory in the bumble bee, Bombus impatiens . Using the Proboscis Extension Response (PER) protocol, we look at stress effects on learning and memory in three experiments. After being trained to a conditioned stimulus, we addressed: (1) the effect of 24 h and (2) 30 min of stress on the recall of this learned association and (3) the effect of stress on subsequently learning an association. We found that 24 h of stress after learning appeared to improve memory recall, and there was a trend in the same direction for 30 min of stress. However, bees that were stressed prior to learning an association did not differ from unstressed bees in their ability to learn or remember an association. Our finding that stress has effects on memory in the bumblebee could have implications for their use in behavioral experiments and for promoting the success of both managed and wild populations. [ABSTRACT FROM AUTHOR]

Across the animal kingdom, many animals build structures. One especially diverse example is that of nest building by birds. It remains unclear, however, what birds know or whether they learn about the structural aspects of the material with which they build a nest. Here we tested whether nest-building male zebra finches would choose the appropriate type of material when building in a novel situation. They did do this: males provided with a nestbox with either a small or a large entrance hole and with nest material of two types (‘long’ and ‘short’) chose the type of material that was appropriate for the box in which they built. Additionally, the birds' material use improved with experience: males building in nestboxes with small entrances became less choosy in their material choice as they became more skilled at inserting material of either length into their nestbox. The birds, therefore, first chose the appropriate materials for the nestbox in which they were building but then modified their handling skills so as to make use of all of the available material. How the cognitive abilities used in this nest-building context compare with those used in solving other physical problems such as tool use tasks is not yet clear. [Copyright &y& Elsevier]

Nests are built by nearly all bird species and can be extremely varied in their structural characteristics, both within and among species. As with a number of other avian behaviours, it seems plausible that early learning might be important in producing adult nest-building behaviour. To examine whether preferences that adults have for nest materials are related to their early-life experience, we experimentally manipulated the colour of the nest in which Zebra Finch pairs built and raised chicks. We then tested these chicks at maturity to determine whether they preferred the colour of the nest from which they had fledged or preferred the same colour as their father. We also examined the overall structure of nests that fathers and their sons built to determine whether the nest a male builds resembles that from which he hatched. When males and females naïve to building were paired as adults and tested for their nest material preferences, they did not prefer the colour of their natal nest. When these males were re-paired and their preference tested a second time, the majority then preferred the colour that their father had preferred (which was also the colour preferred by most of the males). The structural components of a male's nest did not resemble the nest built by his father, but neither did his father's nests resemble each other. We found no evidence that the experience of the nest from which a bird fledges influences his preferences for the colour of nest material or the structure of his first nest. [ABSTRACT FROM AUTHOR]

Whether learning plays a role in nest building in birds is largely unknown. Here we investigated whether the colour of nest materials used to build a first nest affected the subsequent nest material choices made by male zebra finches when building a second nest. Males were tested for their preference for green or brown nest material and then were provided with either their preferred or nonpreferred colour with which to build their first nest. The success of this nesting attempt was manipulated such that half of the breeding pairs had their eggs removed, while the other half were allowed to keep their eggs and fledge chicks. Males were then retested to determine which colour of nest material they now preferred. Males had strong initial preferences for one or other of the two colours of nest material. Males that built a nest with their preferred colour of nest material continued to prefer that colour after nesting, regardless of their breeding success in that nest. However, of the males that built a nest with material of their nonpreferred colour, those that raised and fledged chicks from it subsequently preferred that colour of material for their second nest, while males that suffered a failed breeding attempt did not. Thus breeding experience can influence decisions relating to nest material choice in nest construction in the zebra finch. [Copyright &y& Elsevier]