caa a22 4500 465782337 CHVBK 20180323111958.0 cr unu---uuuuu 170327e19900201xx s 000 0 eng 10.1007/BF00171581 doi (NATIONALLICENCE)springer-10.1007/BF00171581 Why are bumble bees risk-sensitive foragers? [Elektronische Daten] [Ralph Cartar, Lawrence Dill] Summary: In a controlled laboratory experiment, we re-examined the question of bumble bee risk-sensitivity. Harder and Real's (1987) analysis of previous work on bumble bee risk aversion suggests that risk-sensitivity in these organisms is a result of their maximizing the net rate of energy return (calculated as the average of expected per flower rates). Whether bees are risk-sensitive foragers with respect to minimizing the probability of energetic shortfall is therefore still an open question. We examined how the foraging preferences of bumble bees for nectar reward variation were affected by colony energy reserves, which we manipulated by draining or adding sucrose solution to colony honey pots. Nine workers from four confined colonies of Bombus occidentalis foraged for sucrose solution in two patches of artificial flowers. These patches yielded the same expected rate of net energy intake, but floral volumes were variable in one patch and constant in the other. Our results show that bumble bees can be both risk-averse (preferring constant flowers) and risk-prone (preferring variable flowers), depending on the status of their colony energy reserves. Diet choice in bumble bees appears to be sensitive to the "target value” a colony-level energetic requirement. Springer-Verlag, 1990 Cartar Ralph Behavioural Ecology Research Group, Department of Biological Sciences, Simon Fraser University, V5A 1S6, Burnaby, British Columbia, Canada aut Dill Lawrence Behavioural Ecology Research Group, Department of Biological Sciences, Simon Fraser University, V5A 1S6, Burnaby, British Columbia, Canada aut Behavioral Ecology and Sociobiology Springer-Verlag 26/2(1990-02-01), 121-127 0340-5443 26:2<121 1990 26 265 https://doi.org/10.1007/BF00171581 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00171581 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Cartar Ralph Behavioural Ecology Research Group, Department of Biological Sciences, Simon Fraser University, V5A 1S6, Burnaby, British Columbia, Canada aut NATIONALLICENCE 700 1- Dill Lawrence Behavioural Ecology Research Group, Department of Biological Sciences, Simon Fraser University, V5A 1S6, Burnaby, British Columbia, Canada aut NATIONALLICENCE 773 0- Behavioral Ecology and Sociobiology Springer-Verlag 26/2(1990-02-01), 121-127 0340-5443 26:2<121 1990 26 265 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer