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Display Size (display + size)
Selected AbstractsHow do floral display size and the density of surrounding flowers influence the likelihood of bumble bee revisitation to a plant?FUNCTIONAL ECOLOGY, Issue 1 2007T. T. MAKINO Summary 1Most pollination biologists have used the collective pollinator visits to a plant as the measure of its pollinator attraction. However, we know very little about how many returns by the same individuals compose these visits, and how far each visitor travels after leaving the plant. Such behavioural aspects of individual pollinators are essential to understand the patterns of pollen flow among plants. 2We observed plant visits by tagged bumble bees Bombus diversus in a field population of Cirsium purpuratum. By dissecting the collective visitation data into visits made by individual foragers, we addressed how ,visitor density' (number of individuals that visited a plant per 2 h) and ,individual visitation rate' (number of visits made by each individual per 2 h) are related to floral display size (number of flowering heads on a plant) and local flower density (number of flowering heads on neighbouring plants). We also tracked individual bees to determine how display size and local flower density of a plant influences its relative position in a bee's foraging area. 3Plants attracted both regular visitors (bees that visited a plant more than three times per 2 h) and occasional visitors (bees that visited a plant fewer than four times per 2 h). Densities of both types of visitors increased with floral display size, whereas only occasional visitor's density increased with local flower density. 4Individual bees preferred to visit central plants within their own foraging areas, plants with larger displays, and plants with lower local flower density. However, these preferences were independent from one another. Plants with large displays were not necessarily chosen by a bee as the centre of its own foraging area. On the other hand, plants with high local flower density were often located near the centre of a bee's foraging area. 5The observed pollinator movements have implications for pollen flow in the plant population. Plants with larger displays probably experience greater mate diversity by attracting more occasional visitors, but they also assure matings with particular plants by increasing returns from regular visitors. [source] Embodied conversational agents as conversational partnersAPPLIED COGNITIVE PSYCHOLOGY, Issue 9 2009Max M. Louwerse Conversational agents are becoming more widespread in computer technologies but there has been little research in how humans interact with them. Two eye tracking studies investigated how humans distribute eye gaze towards conversational agents in complex tutoring systems. In Study 1, participants interacted with the single-agent tutoring system AutoTutor. Fixation times showed that the agent received most attention throughout the interaction, even when display size was statistically controlled. In Study 2, participants interacted with iSTART. Fixations were on the relevant agents when these agents spoke. Both studies provided evidence that humans regard animated conversational agents as conversational partners in the communication process. Copyright © 2008 John Wiley & Sons, Ltd. [source] No evidence for simultaneous pollen and resource limitation in Aciphylla squarrosa: A long-lived, masting herbAUSTRAL ECOLOGY, Issue 4 2007ROWAN H. BROOKES Abstract For successful reproduction animal pollinated plants must provide resources for both pollinator attraction and offspring production, and theory suggests that resources and pollen delivery limit reproduction simultaneously. We conducted a series of experiments involving supplemental pollination, flower removal, fertilizer addition and foliage removal to investigate the interaction of resources and pollen on fruit-set of Aciphylla squarrosa, a long-lived, dioecious, masting herb in Wellington, New Zealand. Reducing floral display decreased open-pollinated fruit-set, suggesting that display size is a reflection of an optimal investment between attraction and fecundity. In combination with supplemental pollination, resource reduction and fertilization addition did not alter fruit-set, suggesting that changes in resource availability did not limit reproduction in the current year. In addition, supplemental pollination of non-manipulated treatments did not increase fruit-set, demonstrating that plants were not naturally pollen limited. While we found that simultaneous pollen and resource limitation did not occur within a season, this is possibly mitigated by life history patterns including mast flowering and a storage taproot. Multiple year studies are required to further examine simultaneous resource and pollen limitation. [source] | ||||||||||