| | Strategies for controlling gophers (Richardson's ground squirrels) has a long history on the prairies. However control is still a challenge, and farmers continue to look for innovative ways of control.
At the Twin Lakes Ranch near Balzac, Alberta, rancher Phil Norregaard decided to try a new integrated approach. "He realized that they needed to do something different when the price of gopher poison had almost doubled, while other available options had shrunk," says George Stalker, Coordinator for the Bow River Project. "Phil decided to explore constructing nesting platforms to attract hawks and rely on them for gopher control, and contacted me for support."
Both the Ferruginous hawk and the Swainson's hawk make the prairies their home. They rely on trees, crests of coulees or cliffs and even transmission poles for secure nesting sites. For the Ferruginous hawk, ninety percent of their diet consists of gophers. A nesting pair are known to consume approximately 480 gophers every breeding season for themselves and their young.
Nesting platforms or poles can be constructed and installed fairly easily. The poles can be purchased, or with this project a permit was obtained from Forestry to collect trees from approved forest reserve sites. "We built four platforms using trees as the main pole," explains Stalker. "We installed one platform on four quarter-sections on the ranch." Nesting materials were left on the platforms, including twigs and grasses.
Phil Norregaard with Raptor Nesting Platform
Photo credit: George Stalker
Stalker and Norregaard are hoping for at least two nesting pairs to claim the platforms. The hawks often switch nesting sites the following year, and then return after the nest has had time to be rid of pests and parasites. "This year one pair nested in the area, unfortunately on the transmission tower close to the platforms. "We're talking with Alta Link, the company that maintains the transmission lines, and hoping to collect problem nests at the end of the season and relocate them to the four platforms for next year," says Stalker. "If we can convince the hawks to nest on the platforms, rather than the transmission poles, it is a win-win for both of us."
The platforms should be spaced at least 3/4 mile (1.2 km) apart to avoid territorial disputes between neighboring pairs. The platforms should also be located where there will be minimal human disturbance. Although people are a concern, most hawks will tolerate a tractor or other vehicle near the nest area. It is during nest establishment and incubation that hawk species are particularly prone to disturbance. The critical timing for Ferruginous Hawks is April to early-June, and for Swainson's Hawks it's May to late-June. PFRA (Prairie Farm Rehabilitation Administration) in Saskatchewan has also done some research on planting fast growing trees in community pastures and installing nest platforms in these trees. (http://www.agr.gc.ca/pfra/biodiversity/hawk_e.htm).
"We really hoping this integrated approach to gopher management will work," says Stalker. "It offers a good alternative to poisons that are both expensive and a danger to other birds and wildlife." As more platforms are established where gopher populations are high, the more likely hawks will use them for nesting. Farmers can benefit from increased gopher control, while everyone benefits from maintaining and increasing the hawk population.
For more information, contact:
George Stalker |
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