@article{dukas_real_1993, title={EFFECTS OF NECTAR VARIANCE ON LEARNING BY BUMBLE BEES}, volume={45}, ISSN={["1095-8282"]}, DOI={10.1006/anbe.1993.1004}, abstractNote={Abstract Abstract. The variation in standing crops of nectar among flowers within a species is usually very high. This nectar variance may decrease a forager's ability to estimate the mean reward offered by alternative plant species. Consequently, learning performance under high nectar variance may be reduced. To examine this prediction, bumble bees were tested for their abilities to learn to discriminate rewarding from non-rewarding flowers under four levels of nectar variance. The learning rate of bumble bees was significantly lower with nectar variance than with no variance. However, learning rates did not differ among the three levels of nectar variance. The results suggest that under increasing nectar variance bees do not increase sampling period, but instead base their foraging decisions on the less reliable information from a certain maximum number of flowers sampled.}, number={1}, journal={ANIMAL BEHAVIOUR}, author={DUKAS, R and REAL, LA}, year={1993}, month={Jan}, pages={37–41} }
 @article{dukas_real_1993, title={EFFECTS OF RECENT EXPERIENCE ON FORAGING DECISIONS BY BUMBLE BEES}, volume={94}, ISSN={["0029-8549"]}, DOI={10.1007/BF00341323}, abstractNote={The temporal and spatial scales employed by foraging bees in sampling their environment and making foraging decisions should depend both on the limits of bumble bee memory and on the spatial and temporal pattern of rewards in the habitat. We analyzed data from previous experiments to determine how recent foraging experience by bumble bees affects their flight distances to subsequent flowers. A single visit to a flower as sufficient to affect the flight distance to the next flower. However, longer sequences of two or three visits had an additional effect on the subsequent flight distance of individual foragers. This suggests that bumble bees can integrate information from at least three flowers for making a subsequent foraging decision. The existence of memory for floral characteristics at least at this scale may have significance for floral selection in natural environments.}, number={2}, journal={OECOLOGIA}, author={DUKAS, R and REAL, LA}, year={1993}, month={May}, pages={244–246} }
 @article{dukas_ellner_1993, title={Information processing and prey detection}, volume={74}, number={5}, journal={Ecology (Brooklyn, New York, N.Y.)}, author={Dukas, R. and Ellner, S.}, year={1993}, pages={1337} }
 @article{dukas_real_1993, title={LEARNING CONSTRAINTS AND FLORAL CHOICE BEHAVIOR IN BUMBLE BEES}, volume={46}, ISSN={["0003-3472"]}, DOI={10.1006/anbe.1993.1240}, abstractNote={. Insects foraging on flowers tend to restrict their visits to a single species of plant while bypassing other equally rewarding species. This behaviour may result from perceptual limitations, the demands of energetic efficiency, or both. Perceptual limitations may be the product of underlying constraints on the processing of information by pollinators. Foraging simultaneously on several species can lower foraging efficiency through reduced ability to recognize the preferred species among others. This hypothesis was tested in laboratory experiments with bumble bees. Bumble bees learned to discriminate between one non-rewarding floral type and either one, two or three rewarding floral types that differed only in colour. Bees' learning rates were higher in experimental sessions with fewer numbers of rewarding floral types. The results suggest that when bees forage on an increasing number of floral types, their ability to discriminate between these and non-rewarding types is reduced considerably.}, number={4}, journal={ANIMAL BEHAVIOUR}, author={DUKAS, R and REAL, LA}, year={1993}, month={Oct}, pages={637–644} }
 @article{dukas_real_1991, title={LEARNING FORAGING TASKS BY BEES - A COMPARISON BETWEEN SOCIAL AND SOLITARY SPECIES}, volume={42}, ISSN={["1095-8282"]}, DOI={10.1016/S0003-3472(05)80558-5}, abstractNote={Social behaviour requires recognition of and communication among colony members. These types of interactions may select for increased learning and memory capabilities in highly social species. The advanced learning capabilities associated with social life may also promote an increased capacity for learning other specific tasks, such as foraging. Therefore, social bees may show a higher capacity for learning and remembering floral characteristics relative to this same capacity in solitary bees. To test this prediction, the performance of a social species of bumblebee, Bombus bimaculatus (Apidae), and a solitary species of carpenter bee, Xylocopa virginica (Anthophoridae) was compared in three experiments in which bees had to learn to discriminate between rewarding and non-rewarding flowers that differed in colour. In all three experiments bumblebees showed higher learning rates compared with carpenter bees. However, both species showed similar levels of overnight memory retention. The results suggest that social bees have better learning capabilities compared with solitary bees.}, journal={ANIMAL BEHAVIOUR}, author={DUKAS, R and REAL, LA}, year={1991}, month={Aug}, pages={269–276} }