Wednesday, April 08, 2009

April 2nd and 3rd River Survey

I began this river survey starting at the small cliff on the confluence of the Root River and the Mississippi River. I have not spent a great deal of time at this bluff in past years owing to the fact that it does not overlook a wide body of water. I did not find any falcons or see any mutes.

I only stopped for a brief minute down below Great Spirit Bluff and quickly found an adult female falcon perched in a dead snag directly above the cliff mounted nest box.

We have sometimes observed falcons at the Trempeleau, WI cliff that can be seen from the Minnesota side of the river. In four river trips so far this season I have not seen a falcon on this cliff.

Homer, MN cliff: This cliff has attracted falcons for the last three seasons. Last year when checking the eyrie, Neil Rettig dropped his cell phone off of the top of the cliff. Surprisingly, the cell phone still worked when found near the bottom of the large cliff. To not have falcons on this historic nest site after two productive nesting seasons is odd and frustrating.

Hussen’s Cliff: During my last river survey on 3/26/09, we found two adult falcons defending this cliff. On 4/2/09 no falcons were observed. Last year, at the end of the breeding season, I hiked to the top of the cliff and rappelled down several areas. I could not locate any suitable nest ledge that raccoons could not easily access. The owners of this cliff have agreed to allow us to install a small nest box should there be failure again this year.

As I approached Pepin Heights cliff just south of Lake City, MN I could see a bird perched in a snag on the Burr Oak located on the top of this cliff. As we have permission, I raced up the back way to the top of this cliff knowing that I could get a band number from a vantage point used in past seasons. However, my mind played a trick on me. The bird turned out to be a crow. Falcons were observed on this cliff in 2008 and in 2007, but no falcons have been seen in four river surveys so far this year.

I did not stop by the Horizon Milling plant on this trip owing to the fact that we confirmed 29/A is back and was the first of our nest sites to lay an egg once again this year. At this writing, the falcons are about a week into incubation. Look for the first young to hatch the first few days of May.

Red Wing Grain; Red Wing, MN: The adult female *M/D is back again. She laid her first egg on 4/3/09.

I crossed the river in Red Wing and made my way upstream to the Diamond Bluff cliff where we mounted a nest box on the big wall about 18 years ago. Each year since I have made a point to check this cliff, and each year I am disappointed to not find falcons. This cliff is set way back from the river and we have learned that nesting falcons prefer a cliff that directly overlooks a wide body of water.

Turning back down stream, I stopped to view the large cliff overlooking the rail road tracks and river near Bay City, WI. This cliff will someday have falcons. I was able to observe several eagles and a red-tail hawk fly directly out front of this cliff without being challenged. I also noticed that there is a home on the top of this cliff and we need to contact the owners for assistance in monitoring.

I stopped only for a few minutes down below West Bluff near Maiden Rock, WI. I heard a male falcon making a courting wail before traffic forced me to drive off. Two land owners up top of the cliff have reported seeing the falcons defending this historic cliff. This is the cliff where last year they had nested under a large overhang that prevented us from reaching the three young falcons. Dave Kester attempted to swing into the wall and with each swing, his rope began to fray on a sharp rock. Fortunately, I noticed this and had Dave switch to my rope until he got above the frayed part of his rope. It was then that we noticed that this new rope did not have any outer protection like our other static ropes. This rope will never be used again.

I only spent a few minutes down below the large Maiden Rock cliff and did not see any falcons. However, falcons have been seen on each of the past surveys and the people from West Wisconsin Land Trust have also reported seeing two falcons defending.

I spent only a few minutes at Twin Bluffs in Nelson, WI. In past seasons we have seen some falcon activity at these two large bluffs. So far this year I have not seen a falcon.

Maassen’s Bluff north of Alma, WI: It was great to meet with Gary Grunwald once again. When Gary returned from his winter haunts in Florida the falcons had once again beat him back. Gary and I observed the adult female fly into the eyrie that we added pea-gravel to several years ago. We also witnessed an adult male Harrier stoop like a falcon at the adult male falcon perched in a dead cedar snag near the top of the cliff. The harrier made a second stoop then went back up in a soar and drifted off. The adult falcon never left his perch.

Alma Marina cliff: Gary reported seeing two falcons defending this historic cliff a few days before my visit. I was most disappointed to not find falcons on territory during my visit. This cliff has but one good ledge that in the last couple of season had nesting Great Horned Owls. I did not see any owls up in the pot-hole and can only wonder what happened to the defending falcons.

12 Mile Bluff across from the Dairyland Alma power plant: It appears that the falcons are going to nest on the cliff once again this year and not in the nest box up on the stack. We have seen falcons using the perch up at the stack nest as a hunting perch, but most courting activity is taking place on the cliff. How great it is to have a stack nesting pair of falcons also use a river cliff!

Fountain City, WI: Doug Wood, who lives down below this cliff, is our eyes and ears for this nest site. He has confirmed two adult falcons on territory. We have also heard that a local pigeon enthusiast is experiencing some losses of pigeons but is accepting the predation so far, since he is impressed by the falcons' hunting prowess. We hope this respect continues.

No falcons were observed at Indian Head Bluff south of Fountain City this year.

I only stopped for a few minutes down below Castle Rock and did not see a falcon, although I had seen them on each of the past surveys. However, Doug Wood reported not seeing a falcon during a lengthy observation on 4/4/09. I hope this site is productive as in past years, but we are finding less falcon activity on the river cliffs this year.

I crossed the river to Winona, anxious to confirm a report of falcons at Bay State Milling on the south edge of town. We worked with a young teenager named Maggie Lubinski about ten years ago, who constructed two falcon nest boxes for this plant as a 4H project. The nest box has attracted the occasional falcon off and on over the years but for the most part has sat empty since falcons took to the nearby Castle Rock cliff about two miles away. Well 2009 looks promising. Two adult falcons are defending this nest box. The adult female is 43/D, a 2005HY falcon from the Dairyland Power Alma power plant. I did not get a good look at the adult male, but this nest box is only about 230 up with great viewing locations down below. We should get the male’s band on the next visit. There is great interest by the plant employees for their nesting falcons. Everyone is amazed at disappearance of the local pigeon population. It is worth noting that Bay State Milling is located directly between the Castle Rock cliff on the Wisconsin side of the river and the Homer cliff on the MN side. Both cliffs are about two miles away. After leaving Winona, I returned to the Homer cliff. I didn't see falcons, but I could clearly see the Bay State Milling stack house and nest box from directly below the Homer cliff. Did the Homer falcons move to this nest box?

On 4/3/09 I set off for McGregor, IA with hopes to read the band numbers on the Agri Bunge stack house. We mounted this nest box about ten years ago. It attracted a single falcon the following year and sat empty the last nine years. Not now! We have two adult falcons on site. It is interesting to speak to the employees at this plant, who are amazed at the overnight loss of the large resident pigeon population. Dave Kester reported the adult male having a b/g band on his left leg and no band on his right. I spent three hours trying to read his band and only could make out the letter D in the upper portion. This is the second falcon that I know that has lost his BBL band. Sometimes when making the crimp with the anodized BBL bands we see a crack form on the crimp bend. It must be these cracks that are causing the band failure.

I crossed the river at the Prairie Du Chien bridge and made my way upstream to the cliff at Lock and Dam 9. I spent the better part of an hour without seeing a falcon. In 2006 this cliff attracted an immy female and adult male that failed to breed. In 2007 this cliff attracted a new immy female and adult male that produced two young falcons. One died after being bumped from the small ledge by the adult female. In 2008 this cliff attracted an adult female falcon and immature male falcon that failed to breed. So far in several visits this spring I have not seen a falcon.

I headed upstream to visit the Lynxville, WI cliffs, determined to locate the chosen cliff and nest location. I first parked down below Larson’s Bluff and did not see any falcon activity for a long time. I then drove to the upstream cliff and positioned myself so that I could see both cliff walls. After about 30 minutes I saw my first falcon. I found a place to park my car, grabbed the scope and made my way across two railroad tracks, determined to nail down the nesting location. It is apparent why the cliff attracts falcons - it is quite large and directly overlooks the water.

I located an adult female falcon perched in a dead snag with a huge crop. So large I don’t think she could see her toes. After about 30 minutes an adult male flew in with a grackle in his talons and landed about five feet directly above the female. He proceeded to pluck his prey and feathers were flying. The adult female appeared to be dozing. I could see a purple band on the adult male right leg and a b/g band on his left. The dozing female had a branch blocking most the view of her legs, but I did see purple on her right leg. After so many cliff sites that have failed already this year it is rewarding to see this pair of falcons that look promising for production once again.

I crossed back over the river at the Lansing, IA bridge and made my way to Dead Cow Bluff where we mounted a nest box several years ago. This is the first year that I have not seen a falcon visit this nest box. With a scope you can see the poorly constructed fence running the top of this bluff. Hence the unusual name.

The Lansing power plant falcons will be a cliff nesting pair from now on. We removed the nest box from up on the stack owing to stack emission monitoring now taking place where the nest box was mounted. There is a huge construction effort taking place at this plant that will prevent us from using the back side of the plant to view the cliff. I’m hoping that in a week or so, we can access the stack elevator to get a good look at the cliff face and determine where the falcons are nesting this season.

In closing, it is apparent that our cliff numbers will be down this year. We have witnessed growth of the river cliff nesting population for the last nine years. However, it does look like our numbers will be down in 2009. Can only hope that this year is an aberration.

I have plans for another river survey later this week.

Bob Anderson

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