Easy plans | Use nesting poles for ferruginous hawks to help control gophers while assisting an endangered species
Ferruginous hawks may fly lazy circles in the blue sky of a prairie day, but they are industrious when it comes to eating Richardson’s ground squirrels.
That diet, of up to 500 gophers per nesting pair per season, makes them attractive tenants for farmers and ranchers within the hawks’ native range in southeastern Alberta, southern Saskatchewan and southwestern Manitoba.
However, ferruginous hawks are considered endangered in Alberta and threatened on the Canadian species-at-risk list, so Alberta’s sustainable resource development department (SRD) and other agencies are trying to increase nest sites and encourage hawk population growth.
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Brandy Downey, senior species-at-risk biologist with Alberta SRD, said initial efforts this year attracted interest from 25 producers.
So far, those have resulted in six new nesting poles, four of which have nests with young.
“I’m very excited about the fact that we’ve had so many nests show up on these poles because it means our protocol is doing it right this time. We’re putting them in the right spots,” said Downey.
Agencies such as SRD, Multisar, the Alberta Conservation Association and Operation Grassland Community will work with landowners to assess potential sites. Then they will conscript utility companies to supply old poles, installation equipment and labour.
The nesting poles could thus be virtually free to landowners who provide a suitable site.
“You would have nice natural ground squirrel control and save some money on poisons or baits or bullets.”
Downey said utility companies often get involved for reasons of corporate citizenship but also because ferruginous hawks like to nest on power poles and electrical towers, creating a potential hazard for themselves and for the utility.
Ferruginous hawks are North America’s largest hawk species and are often mistaken for eagles because of their size and 1.5 metre wing span. The birds, which are rust-coloured on the back, shoulders and legs, get their name from ferrous, meaning iron, which is reddish brown.
Downey said population estimates from a 2010 survey indicate there are 640 breeding pairs in Alberta, up from 618 estimated in 2005. A large number of voles in the province last year provided plentiful food and contributed to an increase.
However, the numbers, though stable, are still much lower than pre-1992 estimates of 1,700 pairs.
Habitat loss, oil and gas activity and other human disturbance are thought to be the cause, though there may also be issues with the migratory route or wintering grounds in Mexico, Downey said.
Ferruginous hawks favour native grassland in flat and open terrain, along with food such as gophers, voles, rabbits and smaller birds.
Those interested in erecting a nesting pole on their property should contact Downey at brandy.downey@gov.ab.ca or 403-381-5526. Information is also available from Multisar at www.multisar.ca or Operation Grassland Community at www.ogcpsp.com.
