That buzz you might hear among some South Florida bird enthusiasts is about bees — reports that Africanized honey bees, known for their aggressive behavior, are taking over birds’ nesting sites.
In most cases, the bees moved into empty tree hollows or bird houses before birds had a chance to. But there are isolated reports of bees driving out birds that already occupied the nests and stinging baby birds to death, scientists say.
Richard Raid, a University of Florida professor, set up 400 nesting boxes for barn owls in the Everglades Agriculture Area. Over several years, bees established hives in about 50 of them, including at least one that was occupied by barn owl chicks. Raid assumes the babies were stung by the bees. “There’s just hundreds of them flying in and out of the box,” he said. “They totally displaced the owls. The adults never returned.”
In Coral Gables, bees set up housekeeping in several nesting boxes at the home of Daria Feinstein, a member of the Tropical Audubon Society. One of the shelters housed baby mynah birds. Feinstein describes the sight of the bees descending on the nest as something like a scene from a horror movie.
The problem is also attracting attention in other parts of the world, such as Guatemala, where habitat for scarlet macaws is threatened.
“It’s an underrated problem,” said Janice Boyd, an adjunct associate professor at Texas A&M University, whose work focuses on parrots. “In Guatemala, a high percentage of known nesting sites (for scarlet macaws) are taken over by Africanized bees.”
Two doctoral students at the University of Florida are working with Raid on a research project based in the Everglades Agricultural Area in western Palm Beach County, where Raid set up the barn owl boxes as a form of rodent control.
The entomology students are sharing their techniques with the Bird Lovers Club, a non-profit bird education and advocacy organization with members in Broward and Miami-Dade counties. The club is putting up nesting shelters in a wetlands conservation area in Pembroke Pines and possibly other sites for spring nesting season. Cub Scouts from Pembroke Pines and Boy Scouts from Plantation built some of the boxes.
At this point, little has been documented about South Florida instances of aggressive bees driving out birds. But much of the bird-lovers’ community is abuzz with talk about encounters between the birds and the bees.
Some bird advocates are wondering if bee activity is affecting wild bird populations, especially in areas where natural habitat is already limited, said Paul Bithorn, a field trip leader for the Tropical Audubon Society. He said some bees inhabit hollow sections of trees. Other set up housekeeping in hand-built bird shelters residents install in their yards.
“If you … build or purchase a nest box for a specific species and put it in your backyard, you want to attract birds, not bees,” Bithorn said.
The bees drawn to the same hollow spaces as owls, woodpeckers and parrots likely are Africanized honey bees, says William Kern, a University of Florida associate professor, whose field includes urban entomology. The hybrid bees, who are especially aggressive when protecting a hive, are established in various areas of the world, including South Florida.
Two Broward County students — Caroline Efstathion of Miramar and Paul Bardunias of Hollywood — working on their doctorate degrees at the University of Florida’s site in Davie are experimenting in South Florida and Brazil with a technique they hope will repel bees from bird houses and direct them to more desirable traps, where they’d be removed by professionals.
Their study came about as a way to protect endangered species in South America and Central America, and the Everglades Agricultural Area is being used as a model.
The students were in Brazil in February installing about 30 specially treated bird houses in an attempt to protect nesting sites for endangered Amazon parrots.
The bird houses are treated with permethrin, an insecticide that usually is not hazardous to birds but can be toxic to bees.
Along with the treated bird houses, the students set swarm traps that are not treated with permethrin but have other features that they hope will attract the bees.
Exposure to permethrin would either repel a bee, kill it or make a scout bee kind of sluggish while it investigates the nest box as a potential relocation site, Efstathion said. When it returns to the colony, the scout bee performs what’s nicknamed a bee dance to communicate information about a potential new location, Efstathion explained. The idea is that the sluggish bee is going to be less persuasive in the dance than other bees who investigated an untreated trap in the same vicinity.
“We’re trying to give the bees (a site) that that they’d like better than the bird boxes,” Bardunias said.
Efstathion and Bardunias also treated other boxes in Feinstein’s yard, where several nesting boxes she had put in earlier were taken over by bees. In one of the boxes, a bee swarm descended on a nest occupied by baby mynah birds. Feinstein said she was about to pull down all the nest boxes, to avoid bees, until she heard about the students’ project.
In addition to protecting baby birds, the students’ bee-repelling approach also may useful for other areas that bees inhabit, such as irrigation boxes, water meter boxes and soffits.
Among the wild bees that are not managed by beekeepers, Africanized honey bees are more prevalent in South Florida than the gentler European honey bees, because they break off and establish other colonies more often, Kern said. “Because they tend to produce more swarms, they cause more interaction problems with human beings and more interaction with wildlife, and they out-compete some wildlife for nesting space,” he said.
Kern estimated 90 percent of the non-managed wild bees in South Florida are Africanized.