Biology Reference
In-Depth Information
9
h e Regulatory Architecture
of Pollen Hoarding
One goal while I was writing this topic was to determine the kinds of
changes that take place at dif erent levels of biological organization as a
consequence of selection on a colony-level phenotype. Another was to
map mechanisms across levels and construct a cross-level metamap of
related traits and their ef ects. In this chapter, I reconstruct what I have
presented in Chapters 5-8 and present such a map.
9.1 Loading Algorithms
h e regulation of pollen hoarding involves the local loading decisions
(algorithms) of foragers as they visit l owers and recruitment of forag-
ers for resources. Loading algorithms are inl uenced by within-hive
stimuli, such as the quantity of stored pollen and brood pheromone.
Keith Waddington showed that pollen quality also af ects recruit-
ment behavior for pollen, although we don't know how it af ects pol-
len collection at l owers. However, the collection of pollen and nectar
are intimately related. Most bees collect both. Pollen loads are less
dense than nectar and pollen loads of weight equivalent to nectar
would be very large protrusions from the hind legs of foragers. h e
total weight of the loads and probably the aerodynamics of large pol-
len loads place loading limits on bees. A totally loaded bee can carry
about 30 mg of pollen if she does not carry nectar and about 60 mg of
nectar if she does not carry pollen (Figure 2.12). How, then, does a
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