Pollination and nectar larceny by birds and bees in novel forests of the Hawaiian Islands


  • Pryce W Millikin University of Wyoming
  • Samuel B. Case University of Wyoming
  • Corey E Tarwater University of Wyoming




pollination, nectar larcency, nectar robbing, novel ecosystems, extinction driven change, invasion impacts


The extinction of native species and introduction of non-native species may lead to the disruption of biotic interactions. Pollination is a critical ecosystem process that often requires mutualisms between animals and plants. Non-native animals may interact with native flowering plants, with the potential to pollinate or steal nectar (larceny) from flowers without pollination. In the Hawaiian Islands, many native plants have lost their original pollinators. Birds and insects are known to visit native plant flowers, but it is unclear whether they pollinate or steal nectar, whether native and non-native species differ in their interactions with flowers, and what influences visitation to flowers. On Oʻahu, we deployed camera traps and conducted in-person observations on four at-risk species of Hawaiian lobelioids (Campanulaceae). We observed birds, mammals, and insects visiting flowers, with a native bird and native bee visiting most frequently. Regardless of native versus non-native status, bees made contact with reproductive structures during most visits (90.5% of visits), while birds stole nectar during most visits (99.3% of visits). Bee and bird visitation increased with the number of flowers on focal plants. Bird visitation also increased with canopy cover and the number of nearby conspecific flowers and decreased with the number of nearby heterospecific flowers. Our results indicate that bees may pollinate plants that were historically bird-pollinated, while native and non-native birds have neutral or negative impacts on these plants. Broadly, we contribute to an understanding of how native plant pollination can be altered in changing ecosystems.

Author Biographies

Pryce W Millikin, University of Wyoming

 Department of Botany

Samuel B. Case, University of Wyoming

Department of Zoology and Physiology

Corey E Tarwater, University of Wyoming

Department of Zoology and Physiology
yellow-faced bee on a Clermontia persicifolia


Additional Files



How to Cite

Millikin, P. W., Case, S. B., & Tarwater, C. E. (2021). Pollination and nectar larceny by birds and bees in novel forests of the Hawaiian Islands. Journal of Pollination Ecology, 29, 189–203. https://doi.org/10.26786/1920-7603(2021)640




Similar Articles

1 2 3 4 5 6 7 8 9 10 > >> 

You may also start an advanced similarity search for this article.