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Friday, July 1, 1994

Prairie Falcon

After moving to Canada in 1992, I became actively involved with the Alberta Society for Injured Birds of Prey (A.S.I.B.P.), which lead to the opportunity to participate in the annual Bow River expedition. The purpose of the expedition was to confirm the number of breeding pairs of Prairie Falcons along a one hundred mile stretch of the river, plus the construction of some artificial sites in areas where the falcons are absent.
            The Prairie Falcon has been monitored along the Bow River for thirty years.  What follows, is a brief summary of my experience during the trip in June 1994:
            The alarm went off at 7:00 a.m., so after a quick cuppa' tea, I set off for the Strathcona Raptor Shelter. The shelter is owned and run by Karl Grantmyre, the executive director for the A.S.I.B.P. We spent some time checking and double-checking equipment, we secured the trailers that held the two boats that we would be using and, once the last member of the group arrived, we were ready.
            About ten minutes into the drive, we were treated to some aerobatics in the form of a Sharp-Shinned Hawk being pursued, at high speed, by a male Red-Winged Blackbird straight across the highway in front of us. Meant to be the other way around, I thought. However, these blackbirds are highly defensive at this time of year. It was about a three hour drive that lay ahead of us, so I decided to grab forty winks; remembering the stories Karl had told me, I wondered what adventures lay ahead.
            John Campbell Senior and Junior have been running and organizing this trip since the late 60's, and know nearly every nest site, bend and camp-site along the river. John Junior was to be our guide, and has been working with Karl for the past nine years. John provided the boats and generator and Karl organizes the volunteers and equipment. 
 
Peregrine Falcons have been seen along the river, but there were no records of successful breeding. One cold egg was found in 1993 that had been abandoned. It was taken back for analysis at the Peregrine Breeding Facility and was found to be infertile. Phil and Helen Trefry, two dedicated Canadian Wildlife Officers, run the facility.
            We, finally, arrived at our destination, which was south of Calgary and east of Okotoks. A local farmer was kind enough to allow us to camp in his field. The field was located right next to the river, with a convenient inlet from which we could launch the boats. Hills surrounded us littered with coniferous trees, and on the far bank, a family of Canada Geese basked in the sun. A pair of White Pelicans flew gracefully in from the south and landed 25 metres downstream. While, above, a pair of Red Tailed Hawks enjoyed the warm thermals.
            After unpacking the equipment and unloading the boats, we were left with some spare time.  So I decided to unpack my fishing rod and try to catch some of the Rainbow Trout that were swirling up in front of me. Shortly after dropping my line in, Rick Morse, a fellow rehabber and good friend arrived with his brother Steve.
            We then had to make a 2 hour drive to Bassano Dam, where the trip would conclude, to drop off the van and trailer. The dam is home to some 12 nest sites and is about 2 1/2 miles long. With any luck, at least half of the sites would be occupied. The field we left the trailer and van in was home to curlew and godwits, which were none too pleased we were there. Also, teams of mosquitoes were present which hurried our departure back to base. The drive back passed quickly, with the swapping of tales and playing who can spot the most Swainson's Hawks. The remainder of the evening was spent drinking coffee around the campfire and attempting to catch one of the Rainbow Trout that kept surfacing; no such luck.
            The next morning, Rick, Steve and myself were the first up and got the breakfast and coffee sorted out. We were ready to start our first day on "The Bow". By 9:30 a.m. we were on the river, five people in our boat and four in John’s.  Both boats were engine powered, so all that was left to do was sit back and enjoy the scenery.
            Our first eyrie (nest of a bird of prey) was just 500 metres downstream; and as we approached the site, a Prairie Falcon left the nest. This nest was particularly low to the river, at about 25 ft. As we made our way to the nest, the adult circled above us with very powerful wing beats and then would soar up, calling all the time. Once we were at the eyrie, John banded the young and I jotted down the wing lengths and weight. There were three falcons (females) and two tiercels (males) and they were approximately three weeks old. At this age it is quite easy to sex them, as the falcons are considerably larger than the males.
            Next on the agenda, was the construction of some artificial nest sites. This was achieved with the help of a small generator we brought along with two long extension cables; we could drill a hole anywhere on the face of the cliff. John’s party continued down the river, where two other nest sites had to be checked. After a few wrong turns on some inlets, we reached a nice strong cliff-face on which we could work. We chose the best location and set about climbing the 80 ft cliff.  Once at the top, we secured a large iron peg into the ground so that a rope could be tied off to allow us to descend. Karl abseiled down, the drill was sent up to Karl from the boat and about an hour later, he had finished the hole measuring 20” wide by 20” high by 24” deep; just the job!


            We continued down the river to meet up with the others for a spot of lunch. The other team had just sheared a pin on the propeller in some low water, but luckily had some spares. After lunch, while the others concentrated on the artificial sites, we took over the banding duties. Our first eyrie was about 90 ft up and about 12 ft down from the top of the cliff. Karl and I went to this nest site, but we soon figured out we needed to back track down stream to be able to climb the cliff. When reaching the top, the remaining members in the boat directed us along the cliff to get the rope into the right position. After a short abseil down to the nest, I was faced with five very fat and angry young Prairie Falcons. Once in position, I got myself comfortable and safely tied off before banding, measuring and weighing the young birds. About 15 minutes later, I was finished and had gained a few souvenirs for my efforts; my hand looking more like a pincushion from their very sharp talons! All that was left to do was to abseil down to the bottom to be picked up by the boat. 
The remainder of the day was spent banding at four more locations. Eventually, we met up with the boat about four miles short of our next campsite.  The others were putting in the last of the artificial nest sites, so we carried on down, checked one more eyrie en-route then headed for base camp. By the time we got into position to check the last site, it was getting dark and the other boat had already passed us and docked at camp. Just as Karl finished checking the site, which was empty, we heard shouting from the other team. “The boat, the boat!" As we looked over, we could see our boat drifting down stream with Karl’s twelve-year-old daughter Roseanne and Romona, another member of our team in it. Neither of the girls knew how to stop the boat or start the engine! So, after about 1/2 hour of pure pandemonium, running up and down the bank, jumping in the river and rescuing damsels, we got everyone back to camp. Once we got all of the equipment organised, we made a nice cozy fire and relaxed for a while, had a good hot meal and went to straight to bed.
            By ten o’clock the next morning, we were back on the river. During this part of the trip we had to cover as much water as possible to make it to the dam by dusk. The nest sites were few and far between. We were lucky enough to see a Golden Eagle, but no sign of a nest. Our only obstacle to overcome was a weir, but luckily, John had arranged for someone to be at the Portage with a truck and trailer to move the boats and equipment to the other side of the river. After a short break, we were back on The Bow. The next few hours were uneventful, though it was nice to just lay back and take in the scenery and wildlife. We arrived at the dam at about 8:00 p.m., and had already spotted six promising sites; lots of white wash on the cliff, betraying the presence of an active nest. We emptied the boats of all the equipment as we wouldn’t need much for the final leg, set-up camp and had a few well-deserved beers!
            Everyone was up by 8:00 a.m. and back on the river by 10:00 a.m.. We started at the bottom of the dam and worked our way up. Through the day, everyone got the opportunity to band some more falcons and do some more abseiling. The last three eyries to check were fairly near to each other; about a hundred metres between each. Karl guided us using hand signals from the boat below. Six of the sites around the dam were occupied; one with eggs. Out of the fifty three falcons that were banded, the average age was three weeks, with a mean brood size of three young.
            There have been some fluctuations due to the changing gopher population, but over all, the falcons numbers have remained stable over the years. The drive back gave me time to reflect on the last three days and let it all sink in. The Prairie Falcons along the Bow River seem to be maintaining a very healthy population; taking advantage of the abundance of gophers, which are prolific on the prairies. They are also capable of living in close proximity without conflict.