Alarm pheromones emitted by honeybees safely repelled elephants at South Africa’s Greater Kruger National Park in a study led by University of Hawaiʻi at Mānoa insect ecology specialist Mark Wright.
The findings offer a new strategy for preventing the world’s largest land animals from destroying crops or causing other damage in areas where humans conflict with elephants, said Wright, lead author on the study published in the July issue of Current Biology.
Working with colleagues from the Balule Nature Reserve, University of South Africa, ISCA Technologies and Elephants Alive in South Africa, Wright tested a slow-release formulation that uses two of the two dozen compounds found in the pheromone released by African honeybees when they perceive a threat to their colony. The chemicals alert guard bees to mount a counterattack.
Scientists applied the pheromone formulation to white socks, which were weighted with rocks and hung from broken tree branches no more than a meter off the ground around watering holes frequented by African bush elephants. They observed 66 encounters in December 2017 and February 2018. Most of the elephants that came near the formulation exhibited signs of increased alertness and uncertainty before moving calmly away. In the same timeframe, elephants either ignored similar untreated socks or approached the controls, picked them up or even tried to taste them.
“Elephants have sensitive tissue around their eyes, ears and inside their trunks and hate to be stung,” said Wright, a faculty member in the College of Tropical Agriculture and Human Resources’ Department of Plant and Environmental Protection Sciences. “With their acutely developed sense of smell, African elephants may have either evolved or learned behavioral responses to the scent of the bees’ alarm pheromones.”
Wright, who also explores pheromones as control agents for agricultural pests in Hawaiʻi, identified two of the honeybee pheromones that elicit stronger attack responses and contacted California-based biotechnology company ISCA Technologies. ISCA produced the synthetic pheromone mixture and dubbed it SPLAT™.