[mou] conversation about Great Gray Owls

[Jim Williams]

I had the opportunity Friday morning to visit by phone with Dr. James 
Duncan,
manager of biodiversity conservation, Manitoba Wildlife Branch, 
Winnipeg, author of the book "Owls of the World" (Firefly Press, 2003), 
and former student of Dr. Robert Nero, an expert on Great Gray Owls. 
Dr. Duncan spends much of his time studying these birds.

He told me that we are experiencing this owl invasion because of the 
crash of the meadow vole population in those Canadian areas north of us 
in which the owls breed. Because that main prey item was scarce this 
spring and summer, he said, there was virtually no Great Gray Owl 
breeding activity there this year. His banding activities this year 
included no juvenile birds. He monitors owls and voles in two 
locations, one near Winnipeg, the other near Roseau. Voles succeed or 
fail based on weather conditions. Cold, wet weather is hard on them. 
Voles were plentiful in 2002 and 2003, so the owls did well in those 
years. This pattern of feast or famine, he said, occurs every three or 
four years.

The owls are being seen along roadsides because ditches and road edges 
are good vole habitat: moist and grassy.

The best thing that can happen to these owls here this winter is lots 
of snow. Deep snow cover, he said, is good for voles, so it is good for 
Great Gray Owls. They have no problem hunting successfully in deep 
snow. Snow crust usually is not a problem, he said. He said he has 
watched owls successfully hunt through crusted snow that would support 
his weight; he weighs 185 pounds. If winter conditions are good for the 
voles, these owls, he said, will return to their breeding grounds 
heavier than when they arrived here.

He said that he and his research team have radio tracked a number of 
Great Gray Owls. They will move as much as 800k from their breeding 
territory as they seek better food supplies. He said Minnesota gets the 
large number of birds it is experiencing this year because northern 
Minnesota and northern Wisconsin are the southern edge of the northland 
peatlands, offering appropriate habitat for the voles, and because 
birds coming down from the north are funneled in this direction by the 
expanse of Lake Winnipeg.

The birds, he said, should become even more visible as we get deeper 
into the winter and closer to spring. They will begin then to respond 
to courtship instincts, becoming more vocal and perhaps even offering 
courtship displays.

Asked about the number of sightings, he said he did not believe that 
there are more owls involved in this invasion than might have been here 
in other years. What we have more of, he said, is observers.

Jim Williams
Wayzata