2025 FIELD REPORT: ORCHID BEE DIVERSITY SURVEY (PDF)
Date: July 11 – 20, 2025
Location: Explorama’s Napo-Sucusari Biological Reserve, Loreto Peru
Study Site: The Amazon Conservatory for Tropical Studies (ACTS) Canopy Walkway. Platform #2. Forest floor and canopy.
Lead Researcher: Dr. Robert Naczi
Team Members: Dawn Baker, Brice Brittsan, Christa Dillabaugh, David Madden, Carissa Ganong, Roldan Hidalgo, Kathy Hockman, Janet Ort, Garly Aliaga Pashanaste, Karin Pinchi, Liana Pelligrino, Kathy Richardson*, Kerrie Sendall, Cesar Sevillano, David Watson ( *= author of this report)
[Many thanks to Kathy Richardson for her three years of dedication and leadership on this project]
Introduction
With the high level of biodiversity in the Amazon, many species are still unknown, let alone monitored for changes in these diversity patterns over time and space. Scientists often use indicator species to learn about other species’ diversity and monitor change. In the process of building a long-term inventory of orchid bee diversity of ACTS, we will test hypotheses about their distribution and species richness for the forest floor and the canopy. In this specific research project, we will be examining and monitoring orchid bee biodiversity and abundance. The long-term aspect of this project will enable us to look for environmental trends.
Materials and Methods
To attract bees, we began with cotton balls tied on a string. Then, we saturated each cotton ball with a concentrated and unique liquid scent and placed them at and in close proximity to the Amazon Conservatory for Tropical Studies (ACTS) canopy platform #2. We placed scents in alphabetical order at each site, in order to track the particular scent that attracted each bee. The scents were Benzyl Acetate, Eucalyptol, Eugenol, Methyl Salicylate, and Vanillin. We placed each set of five ca. 1.5 meters above the forest floor level and on the canopy platform level (lower platform elevation 22.2 m, upper platform elevation 25.6 m above the forest floor). GPS coordinates for the canopy platform are 3.25105°S, 72.90759°W. Team members monitored the stations from ca. 9:30–11:40 AM each day, for 13-16 July. At the start of each day, we saturated and hung a new set of cotton balls. On the second day, we placed a new cotton ball near the first day’s bait, leaving both baits suspended, in case the first ball maintained attractiveness. On the second day, we added an additional set of cotton balls to each bait site, leaving the first day cotton balls suspended nearby. The third day, we removed the first day’s baits and left the second day bait suspended. The fourth day, we removed the second day’s baits and left the third day bait suspended. At the end of the fourth day, we removed all cotton balls.
We captured orchid bees by hand in ziploc bags, which we immediately sealed and marked with the date, scent, and location. For subsequent captures, we cleaned and reused the ziploc bags. Each day, we synchronized start and stop times for the canopy floor and forest floor.
We froze orchid bees in the late morning for pinning, labeling, and drying in the afternoon. After specimens dried, we stored them in Schmidtt boxes for preservation and transportation.
Results
We documented four genera of orchid bees during the sample timeframe. Euglossa dominated the species collected by far, but Eulaema had a notable representation as well. We observed Exaerete and Eufriesia only on July 16, 2025. We did not collect any specimens of Aglae, the fifth genus of orchid bees.
During four sampling days, we collected a total of 245 bee specimens. We collected 33 orchid bee specimens in the canopy and 212 specimens on the forest floor.
See PDF for Table 1: Numbers of genera specimens collected at each bait at the two sampling sites.
Discussion
In 2023, we collected 158 total orchid bee specimens. In 2024, we collected a total of 100 orchid bees. This year, the total was 245 specimens. Although we spent the same amount of time all three years collecting the bees, we noticed that there were differences in the number of bees from one year to the next. Several factors may have contributed to the differences, especially in the canopy collection location. We noticed the temperature was overall lower than 2024, pressure was very similar between 2024 and 2025, and cloud cover was present less often. Interestingly, the only abiotic factor that changed in any noticeable amount was the relative humidity. In 2024 it averaged 50.9%, but in 2025, relative humidity averaged 64.1%. Abiotic factors were recorded by a PocketLab in the canopy three out of the four days, but the floor abiotic factors were only recorded 2 days out of the four dates, so the data comparisons are only for the canopy location.
Recommendations
One consideration would be further revising canopy placement because the canopy platform was heavily trafficked, and some of the samples were moving quite a bit more than others because of the movement of the walkway when people passed by. While we did try to mitigate that movement, the wood beams we decided upon were still moving, however we are unsure whether that had any impact. Another variable may have been the placement of the lower platform baits so near the anchoring tree. That tree’s proximity to the baits might have influenced the bee’s behavior, as there was not full 360° access.
Next Steps
Identify the species by morphology under microscopes and DNA analysis. Most remaining identifications are for Euglossa species. Collected specimens will be deposited in the Museo de Historia Natural de Universidad Nacional Mayor de San Marcos, Lima.
For additional information or questions about this field report, please contact Dr. Lindsey Swierk (lindseyns@gmail.com), Director of Scientific Research for The Morpho Institute and Associate Director of Research for the Amazon Conservatory for Tropical Studies.
Learn more about the Amazon Research Initiative for Educators (ARIE)
Download 2025 Syllabus