Go with the flow: a case study of migratory beekeeping and its associated costs.

The reasons for relocating honey bee colonies are often economic: to provide pollination services and/or to follow honeydew and nectar flows as they occur. In this case study, we analyzed colony migrations related to flow, modeling distances traveled, and costs per hive using official data systematically collected in Slovenia between 2014 and 2022. During this period, beekeepers recorded between 3,000 and 4,000 migrations annually. In response to economically important forage availability, between 67,000 and 96,300 hives were relocated each year. The most sought-after forage was acacia (Robinia pseudoacacia, 23%), followed by chestnut (Castanea sativa, 22%) and fir (Abies alba, 20%). Migration dynamics varied between years due to weather conditions, resulting in a broad range of cumulative travel distances per year, from 125,161 to 212,080 km. The estimated costs of hive transport per km included motorway tolls, fuel prices, and estimated fuel consumption. Regarding vehicle choice, using a car to relocate a small number of hives (8 to 10) was the most expensive option. A 28-hive trailer for a family car proved to be a near-optimal option, while the most cost-effective method was migration with a truck carrying 72 hives. Nonetheless, throughout the observed period, the cost of migrating 28 hives over 200 km was less than the retail value of 10 kg of honey.