Field Trip to Hawk Ridge

During our Hawk Ridge field trip last week, participants enjoyed good views of sharp-shinned hawks, bald eagles, and Lake Superior.

As the days grow shorter and temperatures begin to drop, birds and humans alike are preparing for winter. While I unpack my winter coat and sweaters to settle into the cold weather, many birds are planning their trips farther south. Raptor migration is already well underway at Hawk Ridge Bird Observatory in Duluth. Migrating raptors funnel through Duluth because most choose to follow the lake shore on their way south rather than fly across Lake Superior. On a good day, observers at Hawk Ridge can see thousands of birds! So far this month 43,000 raptors of 13 different species have passed through Duluth. Broad-winged hawks come through in the greatest numbers, comprising about half of all raptors counted.

Our birds at the museum are preparing for winter, too. Great horned owls and red-tailed hawks are built to cope with cold temperatures, but American kestrels normally need to migrate. Aldo doesn’t have that option, so he has a special hutch built with a heater. We’ll keep a close eye on weather forecasts and turn on his heat when temperatures dip into the 20’s.


Peregrine falcons in Wisconsin

These four chicks were banded this year at the Madison nest site. (Photo credit: Madison Gas and Electric Company)

“Why might a raptor become endangered?”  This was the first question I posed to students at the HACIL Charter School in Hayward last week. They came up with a great list including overhunting, pollution, and invasive species. With Aldo’s help, we talked specifically about the decline of peregrine falcons due to the use of an insecticide (DDT) and how they recovered. Our discussions made me wonder: how are peregrines doing in Wisconsin now?

I headed to the Midwest Peregrine Society’s website to find detailed banding records throughout the Midwest. Though peregrines were taken off the federal Endangered Species List in 1999, researchers continue to band chicks hatched at nearly every known nest site. Wisconsin started with just one nest in Milwaukee when the state’s first captive-bred chicks were released in 1987. The Wisconsin population has since grown to 34 successful nest sites in 2016 with a total of 103 chicks!  With efforts from chemists, politicians, biologists, and falconers, the peregrine falcon is an amazing example of what can happen when passionate people come together to save a species. I can hardly wait to see how our peregrines do next year. For now, I’ll have to settle for recorded nest cam videos until the birds come back next spring!

Positive Reinforcement

Aldo inspects a bite-size quail tidbit offered on the tip of my finger.

There are many ways to teach an animal to do a single behavior, like having a raptor stand on a gloved hand. Falconers use a traditional method called “manning” where the falconer sits with a new bird on glove for an extended period of time with the idea that it will become acclimated after hours of exposure. A more modern approach to training the same behavior uses positive reinforcement.

Positive reinforcement is everywhere in our lives. You lavish your dog with attention if he comes when called. You receive compliments for a new hairstyle. Both of these examples have a reward that makes the behavior more likely to occur again. Your dog will keep running to you if he loves the attention, or you might style your hair the same way to get more compliments. I use the same concept with our raptors, using food as the main reinforcer. Aldo gets a meat tidbit every time he steps on glove or stands still on the scale. New stimuli, like large groups of people, are introduced slowly. Rather than expecting the bird to quickly acclimate, we use food to turn it into a positive environment for the bird. Both manning and positive reinforcement are proven effective, but the latter is favored by education raptor trainers.

New training ideas

Dan (naturalist at The Raptor Center) practices targeting in a training session with “Strix” the Barred Owl.

At The Raptor Center two weeks ago, Aldo and I learned about more than beak trimming. I had the opportunity to talk with naturalists Gail and Dan about raptor training. It is always good to brainstorm with people that might have new ideas and different backgrounds. Gail and Dan proposed lots of ideas for our birds, like target training. “Targeting” is a common behavior used in zoos where the animal learns to touch its nose to an object, usually a tennis ball at the end of a dowel. It is useful to guide the animal around the enclosure or to teach new behaviors. I have targeted with monkeys, rabbits, and tigers, but hadn’t thought to try it with raptors. When we returned to the museum, I used a stretch of Vetrap to transform an ordinary wooden dowel into a target stick modeled after the one The Raptor Center uses. I introduced the new target to Carson (Red-tailed Hawk) and within one week she was eagerly taking food held next to the target. Soon she will learn to touch her beak to the end of the dowel to earn her treat. New behaviors like this keep training interesting and fun for trainer and animal alike.

“Coping” at The Raptor Center

Processed with Moldiv

Like our fingernails, beaks and talons grow continuously. Wild birds have a rough enough lifestyle that they wear down naturally. With an easier life in captivity, we occasionally have to trim our birds’ beaks when they grow too long. To learn how to do that, Aldo and I went on an exciting road trip to The Raptor Center at the University of Minnesota last week. Clinic Manager Lori Arent demonstrated the technique for trimming, or “coping,” a kestrel beak. These falcon beaks are more difficult than other raptors because they have a special notch that needs to be shaped in addition to shortening the whole hook. I observed Lori before it was my turn to cope Aldo. She made it look so easy, but once I was in the hot seat I quickly learned this is a skill that will take some practice. Balancing a dremmel in one hand and holding his beak in the other, it was difficult to maneuver everything at the right angle. I was glad to have someone with so much experience looking over my shoulder. About 10 minutes later, I could finally take a deep breath. Aldo’s beak wasn’t quite as polished as the bird Lori just finished, but it was the proper length and would make it easier for him to eat. Next time he needs a trim, possibly in two or three months, I’ll be ready with this new skill!