LEARNING AND TASK INTERFERENCE BY CORPSE-REMOVAL SPECIALISTS IN HONEY-BEE COLONIES

Undertakers are considered to be among the most specialized of pre-for aging honey bee (Apis mellifera L.) workers. In this study we examined a possible benefit and a cost of the corpse-removal specialty, the im provement in performance with experience, and interference by individu als attempting to perform the same task in the same location, respecti vely. Experienced bees removed corpses significantly faster than less experienced bees and also were less likely to drop corpses while exiti ng the hive (5.5% vs. 14.3% of attempts). Superior performance by expe rienced undertakers might occur as a consequence of learning, or by gr eater ability from the outset. Because active undertakers (greater tha n or equal to 3 corpse removals) did not improve with experience over their own careers, learning was not demonstrated. An extreme specialis t, Yellow 54, removed a total of 114 corpses (33.8% of experimentally introduced dead bees) from the hive over a 13-day period. This is the longest recorded tenure of undertaking to date and demonstrates how a few individuals can dominate this task in a honey bee colony. Yellow 5 4 removed corpses significantly faster than other active bees, but she demonstrated no obvious improvement in performance over her undertaki ng career. This suggests the possibility that active undertakers were more talented than less active undertakers, irrespective of learning. When two undertakers worked together to remove a corpse from the hive, they toot longer to complete the task than did single individuals. Wh en multiple undertakers flew together from the hive, they were less li kely to clear a nearby obstruction than single undertakers and were mo re likely to drop the corpse within 1 m of the hive. Thus, mutual inte rference exacted a measurable cast as a result of the undertaking spec ialization while learning provided few benefits.