A meta‐analysis of single visit pollination effectiveness comparing honeybees and other floral visitors

• Published in: American journal of botany Vol. 108; no. 11; pp. 2196 - 2207
• Main Authors: Page, Maureen L., Nicholson, Charlie C., Brennan, Ross M., Britzman, Anna T., Greer, Jessica, Hemberger, Jeremy, Kahl, Hanna, Müller, Uta, Peng, Youhong, Rosenberger, Nick M., Stuligross, Clara, Wang, Li, Yang, Louie H., Williams, Neal M.
• Format: Journal Article
• Language: English
• Published: United States Botanical Society of America, Inc 01.11.2021
• Subjects: Animals; Apis mellifera; bee; Bees; crop pollination; Ecosystem; Ecosystem services; Flowers; honeybee; Meta-analysis; Plant reproduction; Plant species; Plants; pollen deposition; Pollination; pollination efficiency; pollinator importance; Pollinators; Taxa; visitation frequency; wild pollinator; Apis mellifera; bee; pollen deposition; visitation frequency; crop pollination; pollination efficiency; honeybee; pollinator importance; wild pollinator
• ISSN: 0002-9122; 1537-2197
• DOI: 10.1002/ajb2.1764

Premise Many animals provide ecosystem services in the form of pollination including honeybees, which have become globally dominant floral visitors. A rich literature documents considerable variation in single visit pollination effectiveness, but this literature has yet to be extensively synthesized to address whether honeybees are effective pollinators. Methods We conducted a hierarchical meta‐analysis of 168 studies and extracted 1564 single visit effectiveness (SVE) measures for 240 plant species. We paired SVE data with visitation frequency data for 69 of these studies. We used these data to ask three questions: (1) Do honeybees (Apis mellifera) and other floral visitors differ in their SVE? (2) To what extent do plant and pollinator attributes predict differences in SVE between honeybees and other visitors? (3) Is there a correlation between visitation frequency and SVE? Results Honeybees were significantly less effective than the most effective non‐honeybee pollinators but were as effective as the average pollinator. The type of pollinator moderated these effects. Honeybees were less effective compared to the most effective and average bird and bee pollinators but were as effective as other taxa. Visitation frequency and SVE were positively correlated, but this trend was largely driven by data from communities where honeybees were absent. Conclusions Although high visitation frequencies make honeybees important pollinators, they were less effective than the average bee and rarely the most effective pollinator of the plants they visit. As such, honeybees may be imperfect substitutes for the loss of wild pollinators, and safeguarding pollination will benefit from conservation of non‐honeybee taxa.