Keasar T
Department of Evolution, Systematics and Ecology, The Hebrew University
Anim Behav. 2000 Nov;60(5):639-646. doi: 10.1006/anbe.2000.1484.
Many species of orchids that do not offer food rewards to pollinators bloom in clusters, early in the season, and are polymorphic for corolla colour. Previous studies suggest that the foraging behaviour of insect pollinators may select for early blooming and colour polymorphism. I tested whether pollinator behaviour can also favour aggregated flowering in these species, in a two-stage laboratory experiment on naïve bumblebees, Bombus terrestris (L.). In the first stage, the bees were allowed to forage on three colours of artificial flowers that contained sucrose rewards. In the second stage, I added nonrewarding flowers of a fourth colour and recorded the bees' visits to them. The four types of artificial flowers were either arranged in spatially distinct clusters, or were randomly intermingled. I used two reward schedules for each spatial arrangement: constant refilling of reward-containing flowers and probabilistic refilling. Bees that foraged on clustered flowers flew more often to the nonrewarding patch, and made more visits to nonrewarding flowers, than bees that foraged on intermingled flowers. This tendency was obtained both in the constant reward and in the probabilistic reward schedules. The results support the hypothesis that pollinator attraction may select for clustered, synchronized blooming in flowers that do not contain nectar and pollen rewards. Copyright 2000 The Association for the Study of Animal Behaviour.
许多不对传粉者提供食物回报的兰花物种在季节早期成簇绽放，并且花冠颜色具有多态性。先前的研究表明，昆虫传粉者的觅食行为可能会选择促成早花和颜色多态性。我通过对野生地蜂（Bombus terrestris (L.)）进行的两阶段实验室实验，测试了传粉者行为是否也会促成这些物种的聚合开花。在第一阶段，让蜜蜂在三种含有蔗糖回报的人工花上觅食。在第二阶段，我添加了第四种颜色的无回报花朵，并记录蜜蜂对它们的访问情况。这四种类型的人工花要么排列成空间上不同的簇，要么随机混合。对于每种空间排列，我使用了两种回报模式：持续补充含回报的花朵以及概率性补充。与在混合花朵上觅食的蜜蜂相比，在成簇花朵上觅食的蜜蜂更频繁地飞向无回报区域，并且对无回报花朵的访问次数更多。这种趋势在持续回报和概率性回报模式下都出现了。这些结果支持了这样的假设，即传粉者的吸引力可能会选择促成在不含有花蜜和花粉回报的花朵中出现成簇、同步的开花现象。版权所有2000动物行为研究协会。
