BELLE GLADE—For the spooks that haunt the Everglades Agricultural Area, Halloween happens every night as they swoop through the skies above the sprawling sugar cane fields in search of treats.But these winged apparitions don’t wear costumes and aren’t begging for candy. They’re ghost owls, also known as barn owls and death owls, and they are a welcome, though eerie, sight to sugar cane farmers, said University of Florida researcher Richard Raid.
The birds perform a valuable service, with a nesting pair of barn owls capable of catching and eating almost 3,000 rodents over the course of a year, said Raid and research assistant Cosandra Hochreiter, of UF’s Institute of Food and Agricultural Sciences. Rodents can cause up to $30 million in damage per year to the area’s 750,000 acres of sugar cane, rice and vegetables.
Superstitions about the birds, however, are plentiful.
"Many people in the islands and Central and South America believe that it is bad luck to see a barn owl, particularly during the day," said Raid, who is based at UF’s Everglades Research and Education Center in Belle Glade. "Rumor has it that to see one forewarns the death of a friend or a relative in the very near future."
To others, they are known as ghost owls because of their white feathers and ethereal ability to fly without making a sound, despite a wingspan of 4 or 5 feet. Barn owls also hiss or screech hauntingly, instead of hooting like the wise old owls in storybooks.
"Another thing that gives them an eerie reputation is that they live in abandoned, haunted- looking barns and old buildings," said Robert Stubblefield, the farm manager for the research center, which is the hub of UF’s barn owl research.
Despite their scary reputation, the owls are close to becoming endangered in some areas and could use some human help, Hochreiter said. Population levels in the Everglades Agricultural Area are far below normal because the abandoned buildings the owls love are disappearing, so people need to provide artificial habitats for nesting and roosting,
Hochreiter and Raid are testing models of barn owl boxes mounted on posts to see how receptive the birds are to such homes. Sugar cane grower Wayne Boynton, who has been using various models for several years, said barn owls have moved into all the boxes he has put up on his 3,000- acre farm.
Boynton’s pioneering spirit in installing the boxes has earned him the nickname "Godfather of Barn Owls." But Boynton said he’s happy to provide testimonials for the birds’ pest control prowess and the homemade nesting boxes.
"People ask me what they need to do to attract the owls to the boxes, and the answer is nothing," Boynton said. "It’s like ‘Field of Dreams;’ if you build it, they will come. It’s that simple.
"In areas where you have trees and abandoned barns and old houses, it’s no problem for the owls to find a place to nest, but this is a treeless area with no natural forest. If we want them here, we’ve got to provide nesting boxes," Boynton said.
The farmers need the owls as much as the owls need the farmers. Traditionally, growers have relied on rodenticides, but the chemicals are short-lived and have to be reapplied frequently. Rats and mice also can become bait- shy, rendering the chemicals less effective.
By contrast, barn owls are the perfect rodent control. Raid calls them "nature’s mousetraps," and Hochreiter says they are efficient and deadly.
"If they spot it, and they want it, it’s over," Hochreiter said. "The rats and mice can’t hear them coming."
Hochreiter said researchers can tell what and how much the owls are eating when they examine nesting sites. Barn owls swallow their prey whole, digesting the flesh and regurgitating the bones and fur in the form of a pellet. The owls are not good housekeepers so their nest sites are literally rodent graveyards, littered with the bones and hair of their victims.
The owls have made Boynton a believer, although they may seem less than grateful for his efforts on their behalf.
"When I come out to the farm at night, they swoop down and hiss at me," he said. "But that’s OK. Rats do a lot of damage to sugar cane, and I see far fewer rats on the farm when we have a high population of barn owls. They’re a great alternative to rat baits and poisons.
"You can’t have too many barn owls," Boynton said.