ISSN:
1572-8889
Keywords:
Apis Mellifera
;
Bombus Pennsylvanicus
;
pollination
;
flight
;
directionality
;
search
;
red clover
;
artificial flower
;
foraging
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Analyses of the search patterns of ApisMellifera workers foraging on artificial inflorescences and Bombus Pennsylvanicusqueens foraging on inflorescences of red clover are used to identify a general rule specifying intrapatch search patterns. Bees land, move about the inflorescences in search of nectar, and come to a last-faced position from which takeoff occurs. Last-faced directions are generated by a forward-moving tendency while probing artificial inflorescences or real florets. This tendency is modulated by restricted bee locomotion, caused by the size and shape of the visited inflorescence and the spatial distribution of florets within such inflorescences. The result is that bees tend to circle inflorescences. The process is terminated with an undefined stopping rule, whereupon bees usually depart in the direction they last face. The last-faced direction is a by-product of intrafloral search and becomes less associated with arrival directions as intrafloral search continues. Pollinator flight directionality is usually represented as a frequency distribution of angular changes in direction which typically has a mean near 0° and a variance that increases with increases in energy gain. We show that these characteristics are artifacts of pooling mirror-image movement data sets;a mean of 0° is the result of canceling the means of the left- and right-hand turns. The putative increased variance associated with energy gain is the result of adding the variances associated with left- and right-handed turns. These computational artifacts may be avoided by changing the sign of the left-handed turns prior to pooling with the right-handed turns (or vice versa). Pooling bee visits based only on the number of florets probed can destroy information relevant to studies examining behavioral mechanisms of flight directionality. Analytical problems encountered when turns exceed 360° are also addressed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01053348
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