Individuals sometimes exhibit striking constancy to a single behaviour even when they are capable of short-term behavioural flexibility. Constancy enables animals to avoid costs such as memory constraints, but can also inflict significant opportunity costs through behaviour–environment mismatch. It is unclear when individuals should exhibit behavioural constancy and which types of costs most strongly influence such behaviour. We use a case in which individuals within a population exhibit more than one handling tactic for a single food type to investigate whether costs associated with switching among tactics constrain expression of intra-individual variation. Using wild bumble bees (Bombus spp.) that feed on nectar through flower openings (legitimate visits) or through holes at the base of flowers (robbing), we asked three questions. (1) Do individual bees exhibit tactic constancy within and across foraging bouts? (2) Are individuals willing to switch their food-handling tactics? (3) Is constancy in food-handling tactics maintained by costs associated with switching tactics? We measured energetic costs in addition to handling times. We found that bees freely foraging in meadows were highly constant to a single food-handling tactic both within and across bouts. However, experiments with individual captive bees showed that these bees were willing to switch tactics and experienced minimal costs in doing so. Thus, switching costs do not drive the observed constancy in food-handling tactics of bumble bees within and across foraging bouts.

中文翻译：

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尽管转换成本低，但大黄蜂对花蜜的行为始终如一

个人有时对单一行为表现出惊人的恒常性，即使他们有能力进行短期的行为灵活性。恒常性使动物能够避免诸如记忆限制之类的成本，但也可能通过行为与环境的不匹配而造成重大的机会成本。目前尚不清楚个人何时应该表现出行为的恒常性以及哪种类型的成本对这种行为的影响最大。我们使用一个案例，其中一个群体中的个体对单一食物类型表现出不止一种处理策略，以研究与策略转换相关的成本是否会限制个体内部变异的表达。使用通过花孔（合法访问）或通过花基处的孔（抢劫）取食花蜜的野生大黄蜂（Bombus spp.），我们提出了三个问题。(1) 单个蜜蜂是否在觅食回合内和觅食回合之间表现出战术稳定性？(2) 个人是否愿意改变他们的食物处理策略？(3) 食品处理策略的稳定性是否由与转换策略相关的成本维持？除了处理时间之外，我们还测量了能源成本。我们发现在草地上自由觅食的蜜蜂在比赛内和比赛之间对单一的食物处理策略高度一致。然而，对单个圈养蜜蜂的实验表明，这些蜜蜂愿意改变策略，并且这样做的成本最低。因此，转换成本并没有推动大黄蜂在觅食回合内和觅食回合之间观察到的食物处理策略的恒定性。