Evaluating competition between managed and wild bees in a semi-urban agricultural landscape

Commodities

• Animal Products: honey

Practices

• Crop Production: beekeeping, pollination, pollinator habitat, pollinator health

The decline of wild bee populations is a critical concern that threatens the sustainability of pollination services across many landscapes. Wild bee communities are strongly affected by land management practices and habitat fragmentation, but also by competition with non native species, including honeybees. Although use of managed honeybee hives is important for optimizing production in various agricultural systems, hive-keeping is also growing as a recreational pursuit among hobbyists and homeowners, which may increase regional competitive pressures on wild bee populations for access to limited pollen resources. Consequently, there is a need to understand how honeybees interact with wild bees, and the consequences of such interactions for both managed honeybees and wild bees. Strong competition between honeybees and wild bees could result in population declines of wild bee assemblages, and a corresponding loss of natural pollination services. Here, we ask whether (and to what extent) managed honeybees compete with wild bees, evaluating effects of species overlap on patterns of resource use and biodiversity in the Colorado Front Range region. Our project will establish a collaboration between researchers, growers, and hive managers to examine patterns of floral visitation and nest site use by wild bees in the presence and absence of honeybee hives using an experimental framework that varies cropping system as well as timing, duration, and density of honeybee hive deployment. Project results will help to inform whether there is evidence of ecologically important overlap in the foraging and habitat use patterns of multiple wild bee taxa and honeybees, and how parameters of hive management (hive density) influence this overlap. Project results will be disseminated to agricultural stakeholders via multiple pathways including (1) publishing new extension bulletins on honeybee competition, (2) integrating project data into educational modules for regional Native Plant Master, Master Gardener, and Pollinator Watch extension programs, and (3) stakeholder engagement workshops with growers, professional hive managers, and hobbyists to interpret and discuss results in the context of current hive management tactics. We will employ summative assessments to evaluate project effectiveness by monitoring change over time in honeybee densities across semi-urban agricultural landscapes, analysis of informal surveys (both course survey and WSARE survey tools), text analysis of grower narratives, and web analytics to evaluate use of educational products. We expect our research, educational products, and summative assessments to result in co-produced policy recommendations in our region regarding future conservation efforts for wild bee populations. 

The overarching goal of this project is to quantify the impacts of backyard beekeeping and small-scale commercial beekeeping on patterns of foraging and nesting by wild bee communities, and make specific recommendations to natural resource managers, beekeepers (hobbyist and professional), and the general public on best practices for wild bee conservation. To this end, we address the following research and educational objectives: 

Research objectives:

1. Quantify patterns of floral visitation - Does the presence of honeybees reduce wild bee visitation to flowers? 

2. Assess nest site use - Does the presence of honeybees reduce the probability of nest site use by wild bees?

3. Test whether wild bees affect honeybee health and productivity - Do wild bees affect honeybee health and productivity?

4. Model outcomes for wild bees - What are the long-term prospects for wild bee populations in the presence of honeybee colonies?

Educational objectives:

5. Improve existing programmatic content - Incorporate new modules on pollinator management into existing content in popular extension programs

6. Produce new extension fact sheets - develop new semi-technical brief for backyard beekeepers and conservation-minded members of the general public

7. Stakeholder workshops - engage beekeepers and pollinator conservation groups in workshops to develop relationships, policy recommendations, and long-term research needs