A New York State Museum scientist is one of several researchers who have become the first to use tiny radio transmitters to track bees over long distances in a forest habitat, yielding new insight into the role of bees in tropical forest ecosystems. The bee study research conducted by Dr. Roland Kays, the Museum's curator of mammals, and the other scientists, was published in the online peer reviewed journal PLoS ONE on May 26th.
Armed with radio antennas, Kays and the other researchers worked at the Smithsonian Tropical Research Institute (STRI) in Panama City, Panama, to track unique signals from tiny transmitters glued to individual orchid bees. Although radar had been used to track bees in open areas, this is the first time it has been used in forested habitats. The research opens the door to future studies of bees in temperate forests, such as those in New York State.
Bees are important pollinators for plants worldwide. Pollination is critical for trees to make fruits and seeds, including domesticated edible fruits, as well as inedible species that are found in most New York State forest habitats. However, little is known about the movement of bees because they are so small and difficult to track.
Researchers, using helicopters, discovered that the orchid bees traveled surprisingly long distances, zipping through increasingly scarce patches of tropical forest as they moved pollen between rare flowers that grew miles apart.
"People disrupt plant pollination as they disturb and destroy tropical forests," said David Roubik, senior staff scientist at the Smithsonian. "Radio-tracking significantly improves our understanding of bees and the plants they pollinate. Now we can track orchid bees to get at the distances and spatial patterns involved—vital details which have completely eluded researchers in the past."
The researchers chose 17 iridescent blue-green orchid bees called Exaerete frontalis -- fairly common in the forest. They are larger than New York state honeybees but similar to some of the state's other large bumble bees. Roubik determined that Panama's orchid bees weigh only 0.6 grams without nectar in their stomachs.
"These bees easily carry a 300 mg radio transmitter glued on their backs," said Martin Wikelski, co-author of the research paper and director of the Max Planck Institute of Ornithology, professor at Princeton University and Smithsoian research associate. "By following the radio signals, we discovered that male orchid bees spent most of their time in small core areas, but could take off and visit areas farther away. One male even crossed over the shipping lanes in the Panama Canal, flying at least five kilometres, and returned a few days later."
In the past, researchers have struggled to determine the distances that bees travel, following individuals marked with paint between baits, or using radar, which doesn't work well when trees are in the way. "Carrying the transmitter could reduce the distance that the bees travel, but even if the flight distances we record are the minimum distances that these orchid bees can fly, they are impressive, long-distance movements," said Kays, who is also a research associate at STRI. "These data help to explain how orchids these bees pollinate can be so rare."
Source: Public Library of Science