Cannon Conflict: Alternatives to the artillery
Read part one of this series.
Alex BUTLER and Tyler OLSEN
On a hot July morning, the Geldermans’ blueberry fields on Sumas Prairie are peaceful. The blue sky overhead is free of clouds – and more importantly – starlings.
With 30 acres of blueberry fields, Jerry Gelderman and his son Nathan understand the threat of the invasive bird species that consumes berry crops.
But at the Gelderman farm, no cannons fire. Beyond the normal noises of a farm operation, the only sounds out of the ordinary are the cries of the falcons the Geldermans use to keep the other birds at bay.
Symbat Strek, a falconer who runs Spirit Falconry Service, is contracted to fly her falcons at the farm seven days a week. The predatory birds pose a threat to starlings, which choose to find their meals elsewhere.
Strek has been contracted by the Geldermans for two years, and the family has been farming blueberries for seven. While they have never used propane cannons, Nathan said before the falcons they constantly monitored the fields and used ribbons, electronic squawkers on a timer, orchard pistols and constant monitoring.
Now it’s much easier. The falcons have kept the skies clear of starlings, and Jerry said even neighbours have noticed the absence of birds.
Jerry and Nathan agree that while falconry works for them, it may not be a viable option for all farmers, due to the expense of having a trained falconer visit daily.
Jerry said it is important for people who buy blueberries to understand that while a quiet method of bird abatement may be preferable to cannons, “somebody has to pay for it.”
He said that at Gelderman Farms, where they also process berries, they are able to achieve revenue that allows for the use of falcons. But if a farmer cannot get a sufficiently high return on berries, “that forces you to stay with the conventional methods, like cannons.”
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Before they turn to blasting cannons or expensive falconry, most farmers try a range of cheaper options to repel starlings and other berry-eating birds.
The BC Ministry of Agriculture requires growers to try less disruptive measures to disturb birds before turning to, or increasing their use of, audible devices, which also include pistols and screeching devices that mimic the sound of predators.
Among commonly used alternatives are ribbons of reflective tape or Mylar that can be seen hung along rows of berries around Abbotsford. The ribbons – or anything shiny – are believed to dissuade birds from alighting nearby. The material is cheap – three 50-feet rolls of Bird-B-Gone ribbon costs around $25 – and annoys only birds. However, farmers say the ribbon is also not overly effective.
At his Matsqui farm, Hardeep Harry has strung Mylar tape intermittently from stakes. He says they seem to do little to keep birds off his berries, although they do no harm either. The propane cannon he fires every 30 minutes is more effective, he says.
Nearby, Devinder Brar has strung ribbon at ground level and from high poles. He says that while the ribbons annoy birds and discourage them from landing, they do little to discourage those that decide to land among his berries.
Scarecrows – an old farming standby for hundreds of years – are used in the same manner, although their efficacy varies.
The most effective protection device is netting, which goes virtually unused by the commercial industry, as it is considered impractical for large farms and incompatible with machine-picking. A 2002 agriculture ministry document estimated the cost at nearly $3,000 per acre.
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Birds are surprisingly smart.
A 2009 study by Trinity Western University noted that while visual and auditory deterrents both seem to work at first, birds soon learn that they pose no actual risk of harm.
Some farmers use kites meant to resemble hawks or other predatory birds, and according to the TWU study, those outperformed control measures and auditory devices, including a propane cannon.
The number of birds dropped immediately after the kite was installed, and more than tripled when it was removed. A propane cannon showed less dramatic results, and appeared to decrease in effectiveness as birds became accustomed to it.
The research was a pilot study and the authors, led by professor Karen Steensma, cautioned against concluding too much from the results, citing their limited scope. However, the authors note that previous studies have also documented the ability of birds to become habituated to propane cannons.
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On Downes Road, where blueberry fields commonly abut homes, Onnink’s Farm has built a reputation among anti-cannon residents for shunning the devices.
Seven years ago, after experimenting with a noisy screecher that imitates a bird’s call, Henk Onnink bought a pair of hawks to watch over his 30 acres of blueberries. Henk has since died, but his daughter Arina, who now runs the farm, says his hawks continue to keep away the birds that used to feast on the berries.
“The hawks are very territorial. When a crow would come or any starlings, they just chase them away,” she says. “Our berries are not eaten by birds because the hawks are our bodyguards.”
Onnink isn’t a fan of the propane cannons, calling them “the easy way out.”
“You just put a cannon in and that’s it,” she says.
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But some farmers are so besieged by birds that they say they need every alternative available.
Gary Sandhar has been growing berries at his 40-acre Sumas Prairie farm for seven years. Bracketed by dairy farms on either side, Sandhar found his bird problem escalating three or four years ago.
Sandhar employs a falconer – at a cost of $18,000 for two months – and uses scarecrows, but he also has propane cannons, squawkers and men on dirt bikes.
“At this point, even with all of that stuff, we still lose five to seven per cent,” Sandhar says. His cannons are employed selectively by employees on the farm.
“If you just rely on cannons, that’s not going to cut it,” he says.
He turned to falcons when he returned from a weekend away to find his crop devastated.
Sandhar says farmers need to do what they can to limit their cannon use, but he is also skeptical of efforts to ban the devices.
“The focus needs to be not on banning the cannons; the focus needs to be on finding a solution to the problem,” he says.
Sandhar is doing his part, hosting university students who are studying the issue and counting bird damage. And his farm will also be the site of a high-tech, bird-control experiment in early August.
A company will test out the use of a drone – essentially a remote control aircraft – that could be used to scare away birds.
An early demonstration showed promise, and the price – a one-time expenditure of a few thousand dollars – makes drones attractive. But still, Sandhar cautions: “There’s no one system that works; it’s a combination of systems.”
The BC Blueberry Council is continually experimenting with new alternatives, according to the organization’s executive director, Debbie Etsell.
“Every year we spend research dollars looking at things that would replace the noise devices,” she says.
But before they see widespread use, alternatives need to be tested, Etsell says. The use of drones is just the latest in a series of experiments, not all of which have succeeded.
In one of last year’s experiments, Etsell said “a product was put on the berries, but it wasn’t pleasing to the public.”
The other involved what she would only call “an airborne device.” That failed due to safety concerns for the public.
The council has also experimented with coloured lasers, but she said that too, hasn’t passed testing.
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With options available, each farmer has reasons to use a certain method of bird abatement to protect their crops.
Back at Geldermans, Strek, who is contracted for her falconry services, says she feels sometimes people shy away from trying something new, such as falcons.
“It’s not material, like streamers or cannons, which you can hold. I think that more innovative farms are more into trying it.”
Before the falcons, the starlings would eat the Geldermans’ crop even as it was being harvested, Jerry says. The bird pressure was constant.
All that has changed. Now Nathan says his family can focus on harvesting and processing berries. With blasts from cannons, the birds move from one farm to the other to escape the noise. With falcons, the birds stay away.
“This morning I drove down the road; there’s a blueberry farm about two minutes from here. I saw what they call the ‘clouds of starlings’ in the area. You look at the skies here and it stays clear like this all day.”
(Above photos: The use of Mylar ribbons strung among blueberry bushes or high on poles is among alternatives to controversial propane cannons.
Arina Onnink, owner of Onnink’s Blueberry Farm, inspects blueberries.)