Focus on wild and honey bees: competition for food and protection in northern Germany

_{Photo: UHH / Nesso}

When we talk about bees, many people first think of the honey bee. They are known worldwide as a farm animal and the honey they produce is a popular foodstuff. Honey bees are kept by humans in beehives, in which a queen and up to 40,000 workers live. However, the western honey bee (Apis mellifera) is only one species of the almost 600 bee species native to this country. All other species are summarised under the term ‘wild bee’. These wild bees usually live alone and make a decisive contribution to the stability of our ecosystem.

Like many other insects, bees are also affected by global insect extinction, i.e. the decline in biomass and/or the number of species. For example, 48% of bee species are already considered endangered or even extinct. There are many reasons for this: rising temperatures and dry periods as a result of climate change, the loss of habitats due to the clearing of the landscape, the use of pesticides, the limited availability of food due to monocultures and the increasing sealing of surfaces are threatening wild bees.

However, the situation is different for honey bees. As they are cared for by humans as farm animals, they are less affected by these factors. In addition, beekeeping is becoming increasingly popular as a hobby. Since 2007, the number of honey bee colonies in Germany has almost doubled from 670,000 to around one million. However, this rapid increase, combined with increasingly scarce food resources, could become an additional problem for wild bees. Initial studies on food competition between wild and honey bees are already available, but the results are inconsistent and often only locally significant. A systematic spatial analysis of the competition potential in relation to food availability is still lacking.

Our aim is therefore to carry out such an analysis for northern Germany (Hamburg, Lower Saxony, Bremen, Schleswig-Holstein). We plan to compare the spatially distributed food requirements with the available amounts of nectar and pollen. In this way, we hope to identify possible regional differences and areas with particularly high competition potential. We will publish the results in the form of interactive maps in order to create a basis for future research projects and measures for sustainable beekeeping in risk areas.

To carry out this project, we first need various data sets. Firstly, it is important to know the exact locations of the honey bee colonies kept. As the keeping of bee colonies is subject to notification in accordance with Section 1a of the Bee Disease Ordinance, we will request this data from the relevant authorities. We will also contact the beekeeping associations of the federal states to obtain more detailed information if necessary. Secondly, we need information on the available food resources, i.e. the plant populations in the region. To do this, we will draw on mapping data from various geoinformation systems, such as the Hamburg biotope register or the street tree register. Finally, we also need data on the observed wild bee populations, which are only available from scientific studies on a selective basis.

As this data is all available in different formats, we first need to merge and cleanse it. We will do this using the R programming language and various open source packages such as the ‘terra’ package. For a meaningful analysis, we will supplement the data with findings from the specialist literature, e.g. on the pollen and nectar requirements of the various bee species and the food supply of the regional plant species. As there are probably gaps in both the raw data and the literature data, we will make appropriate error estimates and interpolations.

And here is a short video presentation of the project: