How Can Honeybees And Wild Bees Coexist In Cities?

The rising popularity of urban beekeeping has raised concerns about honeybee well-being and the impact they might have on wild bee populations in cities. A collaborative study of beekeepers, political stakeholders and research institutions, including researchers from the Technical University of Munich (TUM) have developed the "Urban Bee Concept" which includes measures to foster co-existence between honeybees and wild bees in cities.

Doing good for bees - that is the idea behind urban beekeeping. However, the rapidly increasing number of urban beekeepers in many cities is alarming to urban beekeeping associations. In Berlin, it has more than tripled from 2005 to 2022, with similar increases in cities such as Zurich, Paris, and Toronto. Since the hives only house honeybees, their population in urban areas has increased just as rapidly - raising concerns about their coexistence with wild bees in urban spaces. For example, regarding potential spillover of diseases or competition for floral resources when they are insufficiently available. Both topics are currently being researched in several cities.

Vulnerable wild bees

Many people are not aware that there are different types of bees. "In contrast to honeybees, wild bees often specialize in certain plants and habitats," says Monika Egerer , Professor of Urban Productive Ecosystems at TUM. "In addition, they usually live alone and not in large colonies. As a result, their populations recover much more slowly after disturbances such as diseases or too little resources."

New beehives bring entire colonies with high food requirements into an existing ecosystem, as the honeybees can collect large amounts of nectar and pollen in cities. This is particularly problematic for the wild bee populations as floral resources likely have not increased at the same pace as honeybee populations have or might even have decreased due to densification.

The competition for resources is exacerbated when the hives are subjected to high temperatures such as on rooftops, as it is often the case in cities with limited space. The resulting heat stress raises the demand for floral resources to maintain colony temperature. If the surrounding areas offer less of these resources, the competition is even more aggravated.

Promoting coexistence - the "Urban Bee Concept"

The recent study addresses these concerns and proposes the "Urban Bee Concept" with measures to enable the coexistence of wild and honeybees in urban areas:

• Enhancing floral resources, paying attention to the nutrients they provide.
• Reducing hive density and prioritizing specific urban beekeeping actors.
• Promoting honeybee well-being and bee animal rights by banning hives in unsuitable locations.
• Estimating carrying capacities as accurately as possible.
• Controlling bee health and disease dynamics.
• Promote training, education, and codes of conduct via urban beekeeping associations.

"It is crucial to work jointly here, with researchers, conservationists, governance and beekeepers" says Joan Casanelles Abella, who is part of the research team. Especially since the community of urban beekeepers is very heterogenous, ranging from hobbyists with few hives up to large companies with plenty of them, the stakeholders need to work together. The research team points out the great potential of the urban beekeeping associations in both the design and establishment of these measures.

"Many people engage in urban beekeeping because they want to help bees," says Monika Egerer. "With more knowledge and exchange, we can ensure that not only honeybees but also wild bees benefit."