麻豆淫院

Pollinating insects such as bumblebees often repeatedly visit the same type of flower, even when a variety of flowers bloom nearby. This behavior is known as "flower constancy." Darwin speculated that flower constancy was a passive response to avoid the effort involved in remembering the different flower characteristics. However, researchers at University of Tsukuba have revealed that this theory is incomplete, since it focuses too heavily on "memory constraints."

Instead, they found that flower constancy actually results from an optimal strategy that dynamically adjusts to balance the time required to recall different flower types with the time required to move between flowers. The findings are in the journal Functional Ecology.

In the study, researchers predicted how pollinator behavior changes in response to the levels of spatial mixture of plant species present. When different plant species are highly mixed, focusing on one type of flower increases the time spent moving between them, causing pollinators to skip over other species.

In this situation, pollinators should maintain a low level of flower constancy to forage optimally, even if it requires additional effort to recall flower types. Moreover, when species have similar flower colors or shapes, pollinators should further lower their flower constancy, since switching between species then requires minimal effort.

By contrast, when plant species are clustered in groups, focusing on a single flower type simultaneously reduces the costs of both memory retrieval and travel between flowers. Consequently, in such environments, a higher degree of flower constancy is optimal.

To test these predictions, researchers used two types of artificial flowers and examined how bumblebees' flower constancy changed with the levels of spatial mixture and color difference. As predicted, when the two flower types were more mixed and their flower colors were more similar, bees significantly decreased flower constancy.

But when the same flower types were present in clusters, bees maintained a high level of constancy regardless of flower color difference. These findings challenge the widely accepted theory of pollinator flower constancy that has persisted for 150 years. They provide an important update that improves the comprehensiveness of our understanding of pollinator flower constancy in natural environments.