UH Hilo undergraduate researcher examines Hawai‘i’s native and nonnative bee habitats

Geography student Jesse Tabor is doing bee research with his mentor Jonathan Koch (a UH Hilo alumnus now a post doc at his alma mater). The research—identifying habitats of nonnative and native bees—could prove to be critical to preserving Hawai‘i native bee populations.

By Leah SherwoodPhotos by Raiatea Arcuri.

Jesse Tabor sits at desk. On desk is microscope and bee display.
Jesse Tabor

Research conducted by a geography student at the University of Hawai‘i at Hilo is producing vital knowledge about the habitat ranges of both nonnative and native Hawai‘i bees.

Jesse Tabor, a senior at UH Hilo, is doing the research to understand the habitat ranges of native Hawai‘i bees on Hawai‘i island. The project is an extension of his previous work over the summer investigating habitat ranges of nonnative bees found throughout the state of Hawai‘i.

Jonathan Koch
Jonathan Koch

Tabor’s faculty mentor is Jonathan Koch, a UH Hilo affiliate professor of ecology and alumnus who has returned to the university as a postdoctoral fellow specializing in the study of bees. Tabor’s summer research was done as an intern in the Pacific Internship Programs for Exploring Science (PIPES), a ten-week program that gives undergraduates the opportunity to work under the guidance of a faculty mentor. Koch, who is an alumnus of PIPES, says the program is all about engaging students in unfamiliar topics and developing their research skills.

“We work together very closely together and that is the beauty of PIPES,” says Koch. “One goal is to ensure that the interns come out of it knowing how to properly communicate ideas, and that means knowing your audience. We focus a lot on Jesse’s writing and his ability to think bigger and broader about his research. This project is opening up opportunities for him to work with faculty across campus. He is also learning other skills like statistics and computer programming.”

Koch says that Tabor’s findings about Hawai‘i’s bees, in addition to new information about the habitat ranges of both nonnative and native Hawai‘i bees, also shows where those areas could overlap.

“This information needs to get out there,” says Koch. “We don’t know much about the nonnative bees of Hawai‘i, we currently don’t have any comprehensive assessment. In Hawai‘i, there are nonnative bees such as the honey bee and carpenter bee. We don’t fully understand what the impacts of these nonnatives are, but we do know in certain parts of the world honey bees actually outcompete or deter native bees.”

Tabor explains that understanding the home climate conditions of the nonnative bees can help predict the regions where they might be found in Hawai‘i.

“By getting this information, we can identify and anticipate potential invadable areas around Hawai‘i,” says Tabor. “As far as we know there are 21 nonnative bee species present in Hawai‘i. The problems they bring that we are most concerned about are the introduction of pathogens, competition for resources, and nesting space.”

There are seven native Hawai‘i bees listed under the Endangered Species Act since 2016, and identifying habitats of nonnatives and natives could prove to be critical to preserving Hawai‘i native bee populations.

“Native bees are being threatened with extinction because of development,” explains Koch. “They are mostly found in coastal areas. We are still determining their utility as pollinators; they are probably pollinators of a lot of our native plants, but we just don’t know because there is not a lot of research on this subject.”

A box with a couple of dozen bee specimens pinned to the backboard.
Display of bee specimens in the lab of ecologist Jonathan Koch.

Bioclimatic niche

During a summer internship program, Tabor investigated the potential invasive range of nonnative bees in Hawai‘i by looking at their native bioclimatic niche. Bioclimatic niche refers to the set of climate conditions where a species is most likely to be found. Specifically, he wanted to understand if they are occupying the same bioclimatic niche in Hawai‘i as in their native habitat.

In his investigation, Tabor used bee location data from the Global Biodiversity Information Facility, an international open access platform for biodiversity data, and information from the Global Climate Data database on nineteen bioclimatic variables at each bee location over the years 1960 to 1990. He then processed this information in ArcGIS, a geographic information system, to construct and map species distribution models incorporating the bee locations and climate data.

He constructed two models from this information—a native niche model and a Hawai‘i niche model. “The more these maps overlap the more the bees occupy similar habitats in both places,” he says.

Map of Hawaii. Title: Ceratina arizonensis Habitat Suitability in Hawaii. Map is color coded to show high and low suitability islands. At bottom, the words: Ceratiina arizonensis, a twig nesting bee native to the Southwestern United States was introduced to Hawaii around 1950. This map shows high suitable habitat for C. arizonensis on Niihau, Kauai, and Oahu. Photo of the bee in left bottom corner.
Example of a map by Jesse Tabor showing the habitat distribution of a nonnative bee species. Courtesy image.

Tabor then tested the significance of the differences in the maps with statistical analysis. “Due to lack of records we were only able to run statistical analysis for 11 out the 21 species investigated,” explains Tabor. “Out of the 11, nine nonnatives are occupying a different bioclimatic niche in Hawai‘i from their native bioclimatic niche.”

Tabor says this phenomenon is called niche shift. “This means there are unoccupied areas in Hawai‘i where the climate is similar to their native home, but for some reason the bees are not there.”

This suggests that there are other variables keeping these nonnative species from invading unoccupied areas of the island. “Variables that future models will need to take into account include reproductive behaviors, dietary preferences, morphological data, and environmental variables such as elevation, which can be captured with LIDAR,” says Tabor. LIDAR, or Light Detection and Ranging, is a remote sensing method that uses light in the form of a pulsed laser to measure ranges (variable distances) to Earth.

A close up of a bee under a microscope. Jesse Tabor's hands are seen holding small lights on the specimen.
Jesse Tabor examines a bee specimen.

Sharing the knowledge

Tabor and Koch hope to create an online field guide for stakeholders such as farmers to provide information about the habitats of bees found in Hawai‘i. “If we know what the best habitat is for the bees, we can create a field guide for the public that will have these maps in it that will show where these bees may be found as well as their nesting preferences or the flowers they visit,” says Tabor.

Koch says the larger goal is to raise awareness and advocate for entomology and insects. “Insects are a huge part of our ecosystem,” says Koch. “They break down detritus, they help with the carbon cycle, they help clean our water, and they are a huge part of the food web. The problem is that we don’t know what effect the extinction of many of these species will have on the rest of the world.”

Related story

UH Hilo alumnus Jonathan Koch awarded prestigious fellowship to study genomic diversity of Hawaiian bees


Story by Leah Sherwood, a graduate student in the tropical conservation biology and environmental science program at UH Hilo. She received her bachelor of science in biology and bachelor of arts in English from Boise State University. 

Photos by Raiatea Arcuri, a professional photographer majoring in business administration with a concentration in finance at UH Hilo.  

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