Understanding and mitigating bee drownings in open feeders

Whereas open feeders are relatively inexpensive and are easily set up and maintained, they do present a drowning hazard to bees. We observed that bees feeding off the walls of the open container fell into the sugar water because of their incarnation, interactions with other bees and when shooed off the feeder walls while removing the feeder for cleaning. Twigs, angled laths and utility screen perches permitted bees to exploit more of the sugar water surface area and provided drowning bees a platform for self-rescue. Because angled laths and utility screen perches extended over the entire feeder, they offered greater feeding surface area and increased the chances that a drowning bee would quickly encounter the perches for self-rescue than twig perches. Additionally, bees were less likely to fall into the sugar water when removing the angled lath and utility screen perches from the feeders than when removing twigs. Our anecdotal observations identified three characteristics of perches that can mitigate for the drowning hazard. Perches need to: 1. Allow bees to use a greater surface area of the sugar water to reduce crowding while feeding from the container walls. 2. Encompass most of the feeder to improve the chances that drowning bees will encounter the perch and be able to rescue themselves. 3. Allow bees to quickly extricate themselves from the sugar water to minimize sugar crystallization on the bees. The information presented herein provides a practical window into the factors that lead to bee drownings and the type of mitigation that is required. It is of note that we used the three perch types to develop perch characteristics for mitigating drowning hazards. Novice researchers can apply these principles to customize perches based on their specific needs.