While we wait to see whether M/D Decorah will lay a third egg, I thought I would blog a bit about one of our other nests. The owls at Valmont, Dan and Snowflake, nest in a nest box 260 feet up a smokestack at Xcel Energy's Valmont generating station in Colorado. Owls have big wide heads that swivel almost 360 degrees, huge forward-pointing eyes that excel at gathering light, compact beaks, plump bodies, facial disks, and wing feathers with loose barbs that allow them to fly very silently. Owls swivel their heads because they can't (unlike us) move their eyes.

The tufts of feathers on top of Dan's head are neither ears nor horns. Dan's ears are located under his feathers, at the side of his head, and the right ear is usually set a little higher than the left. Sounds from below reach Dan's left ear first, while sounds from above (including echoes) reach his right ear first. The difference gives him aural 'depth perception', which allows Dan to map sounds three-dimensionally.

Humans don't do this very well. If I'm at a concert, I know the direction the music is coming from, but not the height of the stage the band is playing on. Is it three feet high or five feet high? I need my eyes to tell me. Dan, however, can pinpoint the exact location of the band, or his prey, just by listening. Owls swoop down on their prey from above. Dan's ability to hear and map objects in three-dimensional space helps him catch his quarry in low light, heavy brush, and under snow cover - places where eyes aren't much help. Academically speaking, owls accurately localize both the azimuth (horizontal plane) and elevation (vertical plane) of the sound source. If you like to read about geometry, sound engineering, owl hearing, or awesome stereo setups, google that last phrase.

In addition to offset ears, Dan and Snowflake have facial disks. This concave collection of feathers acts somewhat like a parabolic microphone to direct sound to their ears. In the post on feathers, I mentioned that some birds use them to aid hearing. Owls and Harpy eagles both have facial disks and both hunt under limited visibility. Like other many animals that live in limited or low visibility conditions (catfish and star-nosed moles, to name two) they have developed ways to compensate.

So what is Snowflake and Dan's domestic life like? She incubates the eggs and he brings the food - primarily mice, voles, rabbit, rat, and bird. Although he catches it with his talons, he always carries it in his beak. We've seen Snowflake 'incubate' prey in cold weather, presumably to keep it from freezing, but they don't larder up like the eagles do. They lay two to three round white eggs and begin incubating them immediately after laying - in theory. Snowflake does seem to spend more time off the eggs before all of them are laid. When the babies first hatch, Snowflake and Dan spend a lot of time caring for them. However, as the babies become bouncy, rambunctious 'teenagers', both parents will spend more time out on the perch. The teenage owls act a lot like Sarah, Percy, and Bill in the book 'Owl Babies' - "...and they flapped and they danced and they bounced up and down..."

Like the eagles, owls mate for life - but, like the eagles, mates that die will be replaced. Owls are very territorial and will defend their territory against intruders. Several years ago, the nest box at Valmont was invaded by a strange owl. The two females fought quite viciously before one of them - we think the intruder - was vanquished. Dan and Snowflake have also driven off ravens, which can interrupt nesting, and incubated eggs through thick snowfall and icy rain. Like Bald eagles, they are well adapted to cold weather: they even have feather feet to help protect against cold weather and possibly to sense prey.

2011: The Owls Face A Crow

Dan and Snowflake laid the first egg on 02/13/2012. I estimate first hatch on March 10, although it could be a little earlier or a little later. Xcel Energy has still photos of the pair now and should have the streaming cam back up shortly. You can watch them at our website: http://www.farmyou.com/falcon_cams/index.html (click 'Xcel Valmont Owl Cam') or at Xcel Energy: http://birdcam.xcelenergy.com/owl.html

Information from this post was taken from Collin Tudge's 'The Bird' and the following websites:

• Sound localization: http://en.wikipedia.org/wiki/Sound_localization
• Great Horned Owls: http://en.wikipedia.org/wiki/Great_Horned_Owl
• Ears Map Sounds: http://www.asknature.org/strategy/23622b910ce5191565340ef0b67fa2f1#changeTab
• The Raptor Resource Valmont Owl Thread: http://raptorresource.org/forum/index.php/topic,581.1125.html
• Owl Talons: http://www.owlpages.com/articles.php?section=Owl+Physiology&title=Talons
• Owl Babies, the (fiction) Book. I own it, but also this website: http://denisehughesart.blogspot.com/2011/11/owl-babies-my-favourite-illustration.html

Eagles, Weather, and Feathers!

It was hard not to feel sympathy and concern for Mom last night as she lay in the nest after egg #2, rapidly disappearing under a blanket of snow. Fortunately, she had roughly 7,000 feathers to protect her from the weather.

Different sources provide different answers about how many things birds do with their feathers, but all of them agree that insulation is important. The snow piling up on Mom's back last night provided a clear picture of the insulative properties of feathers: Mom wasn't losing enough heat to melt the snow away from her back. I wish my roof was so efficient.

Feather Anatomy

Image courtesy Ask a Biologist: http://askabiologist.asu.edu/explore/feather-biology

There are two basic types of feather: vane feathers, which cover the birds exterior, and down feathers - looser, fluffier feathers underneath the vane feather. All true feathers are branched: they have a central rachis with rows of barbs on either side. However, down remains light and fluffy, which traps air and helps insulate the bird, while flight feathers hook together like a zipper, to form a continuous 'vane'. Personally, I think of it as dressing in layers: the vane feathers form a sort of 'overcoat' underlain by the soft, insulative down feathers. Given that snow also has insulative properties, Mom was quite warm and cozy under her blanket.

So how else do birds use their feathers? According to 'Ask A Biologist', they help birds fly, keep warm, control body temperature, provide weather protection, aid in swimming, diving and floating (waterbirds and piscivorous birds), snowshoe (Ruffed grouse), toboggan (penguins), brace, feel, hearing (owls, harpy eagles), making sounds, muffling sounds (owls), foraging, keeping clean, aiding digestion, constructing nests, transporting water, escaping from predators, sending visual signals, and camouflage. I think I'm jealous!

Since feathers do so many things, it is unsurprising that they come in more than one type.

Types of Feathers

Image courtesy Ask a Biologist: http://askabiologist.asu.edu/explore/feather-biology

The feathers we find dropped in the woods most often are tail and flight feathers. They seem the same but are actually a little bit different. Tail feathers are balanced evenly left and right of the rachis, while flight feathers have a wider and narrower side. This helps them cut through the air with very little drag. Of course, wing shape also influences flight, but that is for another post. The downy feathers that are good for warmth are shown on the far right. Semiplume feathers are also insulative and help water birds float (although some diving birds are more concerned with going deep - their feathers become waterlogged to help them sink). We think the bristle feathers, found around eyes, nostrils, and sometimes the mouth, help protect those sensitive areas. Filoplume feathers are can be found around the tail and flight feathers. They are thought to be used to sense when the flight feathers need to be maintained.

Although feathers seem light, all of them put together weigh roughly two or three times more than a bird's skeleton does. They also require a lot of maintenance. Most birds have a preen gland near their tails. This gland secretes oil which they spread over their feathers with their beaks. Preening helps remove dust, dirt and parasites from feathers and also aligns them properly. Even with care, feathers eventually begin to suffer damage and must be replaced through molting - an itchy-looking process that renders some birds (but not eagles) flightless. However, the benefits of feathers - flight, protection, insulation, display - far outweigh their costs. We sleep warm in our beds with the benefit of furnaces and blankets. All Mom and Dad need are their feathers.

For more information on feathers, I suggest this website: http://askabiologist.asu.edu/explore/feather-biology. I also took some information from Colin Tudge's book The Bird.

Egg Questions and Answers

We have the first Decorah Eagle egg of 2012! Mom laid it last night at 7:47 CST. Here is a video of the event (by razzle):

Egg Questions and Answers

How long does it take a bald eagle egg to hatch?
There are two ways to think about this: from egg laying to hatch, and from pip to hatch.

• From egg-laying to hatch: Most experts say 35 days, give or take a few. It took the Decorah Eagles 37 days in 2009 and 2011, and 36 days in 2010. 35 to 37 days is a safe bet. 
• From pip to hatch: Pipping occurs when the baby eagle's egg tooth first breaks through the eggshell. It can take as long as a day for the chick to fully hatch. 

How many eggs will the eagles lay? Will all of their eggs hatch?
Although the most common clutch size for eagles is two eggs, the Decorah Eagles have a history of laying three eggs. The breakdown among bald eagles in general is as follows:

• 79% of clutches have two eggs
• 17% of clutches have one egg
• 4% of clutches have three eggs

The eagles hatched all of their eggs in 2009, 2010, and 2011; however, fertilized eggs can fail to develop due to extreme cold, soft shells, or microorganisms. We are hopeful they will have another great year, but we won't know until it happens.

When does incubation begin?
In northern climates, Bald eagles lay eggs when it is still quite cold. They begin incubating immediately after the first egg to prevent the egg from freezing. The eggs hatch the same order and roughly the same interval in which they were laid. While the eaglets are still young, it is possible to identify hatchling number one by its size: it is older and therefore bigger than its nest mates. As the eaglets grow, this difference disappears.

Does Dad help incubate the eggs?
Based on our observations of the Decorah eagles, yes! Before all of the eggs are laid, Mom spends most of the time incubating and laying eggs. Once she is done, Dad incubates about 50% of the time.
Having said that, other nests have reported different divisions of labor, with Mom spending much more time incubating than Dad. We don't know why the eagles act differently from nest to nest, but they do.

Oh no! The eagles aren't sitting on their eggs!
Caring for eggs is a serious business. Everyone knows that eggs shouldn't get too cold, but they also can't get too hot, or the embryos will die. The adults sit on the eggs when they need heat and get off them when they need to be cooled. In particular, the Decorah Bald eagles lay eggs and care for nestlings in late winter and early spring, so their challenges include snow storms, ice, and rain. These things can be frightening to us, but Bald eagles have been coping with them for tens of thousands of years. It is okay for the adults to spend some time off their eggs.

The adult eagle also turn their eggs regularly. Turning the eggs helps keep them all at the same temperature and prevents the babies from sticking to the insides of the eggshells.

What do Bald eagle eggs look like, and how large are they?
Bald eagles lay white, oval shaped eggs. The eggs weigh approximately 125 grams or 4.4 ounces, and are on average about 2.9 inches long and 2.2 inches wide. Size-wise, they are just a tad smaller than a tennis ball, although tennis balls are round, not oval.

What causes the egg to hatch?
Mom and Dad Bald eagle apply heat through incubation, which causes the embryo to grow. At a certain point, it penetrates the air cell - that white sack-like membrane that can also be seen in chicken eggs - and its egg tooth penetrates the shell, creating a hole or pip. It usually hatches 24 to 48 hours after first pip.
The yolk of the egg is absorbed into the baby's stomach at this point, which gives it the energy it needs to hatch.

What is a brood patch?
A brood patch is a bare spot where feathers are missing. Hormonal changes linked to reproduction cause feathers to fall out, which creates a bare patch of skin that allows the incubating bird to better transfer heat to the eggs. Bob estimates that a Bald eagle's skin temperature is about 101F.

Some Bald eagles develop brood patches and some don't. We have not seen a developed brood patch on any of the three adult eagles we have monitored in Decorah, and they all incubated their eggs successfully.

Do Mom and Dad mate for life?
Yes, but if one eagle dies, another eagle will replace it.

Decorah Eagle Egg Videos

• How to tell the difference between Mom and Dad: http://youtu.be/5lARYcL5A50
• The first egg of 2012 being laid: http://youtu.be/j3NjcdT-4U4
• Dad and his new egg: http://youtu.be/G4MYx2J9n8w
• The 'Decorah Shimmy' from 2011 - the eagles settling on their eggs: http://youtu.be/8U_pme0dPhs
• 2011's first hatch: http://youtu.be/8U_pme0dPhs

We also have a third egg at Valmont! Snowflake laid her third egg early this morning or late last night. When we had chickens, I used to think of this time of year as the 'spring egg flood'. It looks like the egg flood has started! Here is a pic from the Valmont nest:


Happy birdwatching, everyone!

We are coming into our busy season! The Fort St. Vrain Bald Eagles laid their first egg yesterday - the same day they laid egg #1 last year. If the Decorah eagles do the same, we won't see an egg there until February 23rd. Note the size difference between Dad (top left) and Mom (lower right). Mom is clearly much bigger than Dad.


The Valmont Great Horned Owls laid their first egg on 2/13/12: 8 days earlier this year. Snowflake and Dan are already on egg #2. Here, Dan brings Snowflake a nice mouse.


So when can we anticipate hatch? Based on last year's dates....

• Valmont Hatch estimated: 3/10/12
• FSV Hatch estimated: 3/28/12

An owl was heard at the Decorah Eagle Nest last night. Video by Razzle:

Watchers probably remember some owl scares last year as well. This is scary for us, but life as usual for the eagles.

Thanks for the photo caps and dates - they are very helpful in tracking important dates!

There were a lot of comments about eagle growth rate on Facebook this morning. According to Gary R Bortolotti, bald eagles may gain more weight per day than any other bird in North America. As in other animals, different body parts may reach adult size at different times. The growth of the legs will be complete about half-way through the nesting period, but the beak and flight feathers won't reach adult size until after the eaglets have fledged, or left the nest. In fact, an eagle's juvenile flight feathers are longer than its adult flight feathers, which it won't get until it is 3 - 4 years old.


The two eaglet pictures are the first and last photographs taken, over a period of slightly less than a month. That should give you some idea of the physical changes the eaglets go through as they grow, although the photo album makes it even clearer. Our little Decorah babies will be taking to the wing before we know it.I've got a Facebook album of Forth St. Vrain eaglet growth 2010, published here: FSV Album

The kestrels have laid a third egg. The photograph of the female kestrel clearly shows what I've heard called her "eye spots". Although no one knows for sure why she has them, the most commonly accepted theory is that they help frighten attackers away. Unlike falcons and eagles, she should lay a bunch of eggs, although not all of them will hatch. Again, unlike falcons and eagles but like many other birds, kestrels are sexually dimorphic in plumage - males and females have different plumage. Wikipedia reports that plumage has more variation between the sexes than size.  Click on the picture for a larger view.

The Decorah eagle babies seem to have gotten off to a nice start today - thank goodness the bad weather is gone!



Mother eagle sheltering her young

Despite today's snow, ice, and rain, the eagle family is doing fine. The parents were very careful to keep their babies sheltered. You can see Mom holding her wings out and up to keep the rain and snow from her young. The bowl of softer materials that the eagles built in the larger nest also helps keep the babies away from the wet. I hope this is the last snowstorm the eagle family faces.

We are also looking forward to peregrine season. I've got some estimated hatch dates:

• Dairyland Genoa: 5/10
• Xcel Sherco: 5/11
• Great River Energy: 5/11
• Xcel Blackdog: 5/16 
• Xcel King Plant: 5/19

The Xcel Pawnee kestrels have laid egg #2. I don't feel quite as comfortable forecasting hatch for them, but I'll guess (a little weaker than an estimate) that hatch will occur around 5/20/2011. The kestrels are very fun to watch - they normally have a large brood which grows very quickly and behaves much more frenetically than the eagle young. Here is a link to a kestrel laying eggs (this is not one of our sites, but the video is very nice):

http://youtu.be/EGmzbS7IOVE

The Valmont owlets are growing rapidly. I need to thank the faithful forum members who have kept me up to date since we are having forum problems. I love these pics and would not get them otherwise. Click the Valmont Owl link in our nestviewer to watch this nest:

http://www.farmyou.com/falcon_cams/

The address looks a little odd because I moved the cams page to another domain (thanks, Ken!) to try to offload some traffic. But it is still the Raptor Resource Project. You can also visit our facebook to talk with other eaglecam fans:
http://www.facebook.com/pages/Raptor-Resource-Project/103786266324668

Eagles incubate for roughly 34-37 days, according to a number of online sources. Last year, the Decorah eagles laid three eggs: one on February 25, one on February 28, and one on March 5. The first eaglet hatched on April 3. This year, the eagles started laying eggs a little earlier, but had the exact same spread: February 23, February 26, and March 2nd.

Eggs in snow.
The eagles are able to incubate
successfully even in this!

As cam watchers have observed over the years, eagles incubate during some very difficult weather. The eggs are laid in a cup of grasses and other soft material (including corn stalks) that raise them above the "platform" of the larger nest. This insulative cup helps retain the heat of the adult eagles and provides additional protection from rain and snow. It also helps keep eggs from breaking (sticks and branches provide a hard, irregular surface) and is nicer for the adult eagles to incubate eggs in - at the risk of being anthropomorphic, I would prefer a bed of soft grasses to one of hard sticks any day.  I suspect the eagles feel the same way.

Some websites state that both male and female eagles are involved in building the nest, while others state that it is usually the female who places branches in the nest. In our experience, both the male and female eagle are involved in building the nest. Bob has observed that nest building is part of the eagles' courtship ritual: bonding begins with courtship and continues through nest building, copulation, incubation, and raising young. Both eagles bring sticks and nesting material in, both place sticks and material, and both move the other eagle's sticks around.

Eagles may also have a brood patch. Feathers are wonderfully insulative and great at shedding water, but can interfere with a bird's ability to transfer body heat to the developing eggs. The brood patch is a bare patch of skin that is well-supplied with blood vessels, making it easier for birds to transfer heat to their eggs during incubation. I don't have a photograph of a brood patch, but there is a real nice one on the Norfolk Eagle site: http://eaglenest.blogs.wm.edu/2011/03/05/incubation-brood-patch/

So who incubates more: the male or the female eagle? The female eagle incubates more, but the male shares incubation duties as well. This is not the case in all birds or even all raptors: the female owl at Valmont, for example, does all of the incubation duty.  In addition to sitting on the eggs, both birds also roll the eggs. This helps assure that all parts of the egg receive heat and prevents the developing embryo from sticking to the egg shell. The parents are very careful not to puncture the eggs with their talons and sometimes "ball" their feet to keep  from damaging them.

As the embryo grows in the egg, it develops (among other things) a sharp point on its beak, called an egg tooth, and a muscle called the hatching muscle. The hatching muscle tips the developing bird's head back. Once it is large enough, the egg tooth will come into contact with the inside surface of the egg. As the chick rotates its sharp egg tooth pierces the egg, causing first a "pip" (hole or crack in the egg) and eventually breaking all the way through.  It is not usually a quick process, and you can hear the babies as they hatch out. 

Pip in egg at left

The eaglets are altricial. According to wikipedia: "In bird and mammal biology, altricial species are those whose newly-hatched or -born young are relatively immobile, lack hair or down, and must be cared for by adults; closed eyes are common, though not ubiquitous. Altricial young are born helpless and require care for a comparatively long time."

The eaglets are not able to thermoregulate, or control their body temperature, until they are 10-14 days old. During this time period, the eagles (usually but not always the mother) stick very tight to the babies. On a warm day you may see the baby eaglets exploring the nest, but on a cold or rainy day, they will be sheltered under a parent or two.

The eaglets will go through a number of physical changes as they grow. On hatching, they will be covered with a light-colored down that is uniform in color. The baby down will be replaced by a darker, medium-grey second down when the babies are between 9 and 11 days of age. Juvenile feathers will start to appear when the young eagles are around 24 days of age. These feathers will be dark, since eagles don't develop adult plumage (dark body, white head) until they are around three years old. The color of the eaglets' beaks and talons will also change as they grow.

Birds grow very rapidly and, according to Gary R Bortolotti, bald eagles may gain more weight per day than any other bird in North America. As in other animals, different body parts may reach adult size at different times. The growth of the legs will be complete about half-way through the nesting period, but the beak and flight feathers won't reach adult size until after the eaglets have fledged, or left the nest. In fact, an eagle's juvenile flight feathers are longer than its adult flight feathers, which it won't get until it is 3 - 4 years old.

For more reading on bald eagle growth and development, check this link out: http://elibrary.unm.edu/sora/Wilson/v096n04/p0524-p0542.pdf

On 3/11/11 I made my first of many big river surveys for falcons on cliffs.  My first stop was under Leo's Bluff near Waukon Junction, IA.  I was pleased to quickly locate two adult falcons back at this cliff.  I saw the adult male falcon strafe a young BE sending a stream of feathers raining down.  This is one of the better cliffs on the Mississippi River to watch and hear the courting falcons.  The road down below this cliff has the least amount of road traffic and least amount of trains. 

I then went to the Bunge North America grain elevator in Mc Gregor, IA.  I found two adult falcons on site. The adult male up near the nest box and the adult female perched on a nearby cliff face.  I stopped in the office to make sure they were aware that the falcons have returned.  I was told that they knew the falcon were back because one of the falcons was quite vocal.  I've never heard of this complaint before.  Before I left the site I parked my car directly under the adult female perched on a dead snag on the cliff face.  The falcon was wailing and she is indeed quite loud.  I could still hear her after driving around the corner of the cliff and all the way to the elevator office.  I stopped back in the office and told everyone that this wailing sound that is part of courtship behavior and should end soon. 

I crossed over the bridge to Prairie du Chein and made my way upstream.  No falcons at the small lock and dam #9 cliff.  I did find two adult falcons at the Lynxville, WI cliff on the northern cliff.

I continued my way upstream and crossed back over the river at the Lansing, IA bridge.  No falcons at the Guider's Bluff, formerly known as Dead Cow Bluff.  I contacted the owners of this cliff as some people have also called this Achafalaya Bluff.  Mrs. Guider was home and I asked her if their cliff was also known as Achafalaya Bluff?  She told me that she has never heard this name before and it has been in the family for 70 years.  So, it appears that the power plant cliff just a short ways downstream is indeed also known to be Achafalaya.  I did find one falcon at the power plant cliff that from now on should be called Achafalaya Bluff.  Returned home 186 miles.

I set off again on another river survey on 3/13/11.  Started out at Lansing, IA and made my way upstream.  No falcons seen at Princess Point near Reno, MN. No falcons seen at the Brownsville overlook cliff. No falcons seen at the Shellhorn cliff.

Saw one adult falcon at Great Spirit Bluff near Dresbach, MN.  I found two adult falcons at Queen's Bluff aka The Bandshell.  This was the first Minnesota cliff overlooking the Mississippi River to fledge a young falcon.  The adults at that first nesting season were two falcons that we captive bred and raised in a rock line room to help imprint them to cliffs.  Both of those adults are now long gone and have been replaced but in our hearts we will always know just how falcons came to first nest on this cliff. 

Heading upstream as I approached the little burg of La Moille, MN. I could see the large cliff face of Trempealeau, WI.  Someday we will have falcons on this cliff as it towers directly over the main channel of the river and several times now I have seen falcons here.

Sadly, no falcons again at the Homer, MN cliff.  I stopped and met with the owners of this historic falcon nest site.  Turns out they have been one of the many followers of the popular RRP BE Cam.  We discussed installing a nest box on the cliff face to improve odds of attracting nesting falcons.

I stopped at Bay State Milling in Winona, MN and found one falcon back on site near the nest box.

Crossed the river in Winona and parked for about 45 minutes under Castle Rock, a lovely cliff about a 1/2 mile upstream from the bridge.  I did not see falcons on that visit but Gary Grunwald reported two falcons courting over this cliff a few days before.  Last year we had two falcons at this cliff before they moved off and it was sad to see this cliff that has had nesting falcons on for so many years sit empty.  Hopefully we will have a successful nesting pair this year.

No falcons seen at Indian Head or Fountain City.  I did notice that the perch on the front of the Fountain City nest box is broken and we will need to rappel down to make repairs.  I now use wooden closet rods for perch material as it is much more durable than using treated 2X2 boards.

As I approached the south end of Alma, WI I saw a male falcon fly from the nest box up on the stack to 12 Mile Bluff cliff directly across from the plant.  He flew back and forth across the cliff indicating to me that he was courting a female.  I stopped for a few minutes and located one falcon perched in a tree up cliff top. 

Spent a few minutes at the Alma Marina cliff where falcons once bred in the single pot hole on the cliff face.  There were about a dozen eagles flying all around the face of this cliff.  No falcons.

Met up with Gary Grunwald at his home directly under Maassen's Bluff.  He has not seen falcons as of this writing but will call as soon as he does.  We have had territorial pairs nesting at this cliff for many years.  However, last year there were two falcons on site but just before what would be egg laying time they disappeared.  Can only hope 2011 is productive.

No falcons at Maiden Rock or West Bluff.  Lake Pepin was still locked up in ice.  This should break any day now.  I crossed the river again at Red Wing, MN and stopped by Red Wing Grain.  I could easily see a falcon at the new nest box.  This is a new falcon nest nest box design that I constructed and supplied to Red Wing Grain.  When you open the top up to the nest box the front is blocked off.  No more worrying about the young falcons falling out and no more having to hang out in space holding something out front to keep the young falcon towards the back of the nest box when being pulled for banding.

It was great to be back on the river.  Soon we will need to inspect our ropes and gear for another banding season.  I will make another river survey this next week.

Please let me know if you have any questions.

The Decorah Eagles laid their third egg today! PeggyJean posted this nice closeup.

In his book "Oology and Ralph's Talking Eggs" Carrol Henderson discusses egg shape. According to Henderson, there are four different general shapes: elliptical (including round/spherical), pyriform, oval, and subelliptical. There are short, medium, and long categories within each, so 12 basic shapes are possible. Bald eagles lay oval eggs that are about the size of a tennis ball, as you can see here. This is the most common shape (Henderson refers to it as the default shape) that are probably most easily formed in the egg as the egg passes through the oviduct.

So how are eggs formed and marked? Some more Henderson:
"The fertilized ovum and yolk are released from the bird's ovary and then enter a portion of the oviduct called the magnum. There the egg white, or albumin, is added around the yolk. In the next portion of the oviduct, called the isthmus, soft inner and outer membranes enclose the egg white. Finally the egg, blunt end first, enters the uterus for an extended period of time where the shell is formed. The pigments (porphyrins) that create colors and patterns on eggshells are produced by the breakdown of hemoglobin from ruptured blood cells...Pigment oozes through the lining of the oviduct and onto the forming shell. Depending on how the egg is moving or twisting in the oviduct, this process results in the creation of spots, streaks, and blotches, with most markings usually at the larger blunt end of the egg."

Of course, shape and color can also protect eggs. Pyriform eggs have a tapered shape (image found on internet). This helps the eggs pack neatly into a nest for incubation, since the pointed ends all face the center; lessens the change of the eggs falling from a ledge, since the eggs roll in tight circles, and may help emperor penguins keep their eggs located on their toes. While I think of eggs as being white, color and markings can help make eggs less visible to predators. Some birds even camouflage their eggs with down or vegetation to hide them.  

In Decorah, the male and female eagle will take turns incubating their three eggs until they hatch on roughly April 1st (it could be a little later, since incubation takes roughly 35 days). This will keep the eggs warm and help protect them from predators like raccoons. The parents will roll the eggs - something we've already seen - pick at the nest, doze, and eat. They will be very busy once the young eagles hatch!
Here's a video of the third egg being laid. Thanks to the many Raptor Resource Project forum members who collect and post photographs and videos.

One of the Decorah eagles enjoys a squirrel on Christmas morning. I am glad to see it after a day's absence. It struck me, as I was going through the dailies, that the eagles must be very warm. The first pic below was taken yesterday, after the last snowstorm. The second was taken today, after the eagle had eaten as much squirrel as it cared to.

The eagle melted a lot of snow while it ate the squirrel - more than I would have thought.

The Fort St. Vrain eagles in Colorado are also busy working on their nest. They aren't dealing with the snow and ice that the Decorah eagles are. In fact, the shot below makes it look like the eagles are back to eating turtles again - that round object looks somewhat like a turtle plastron to me. The FSV eagles ate a lot of turtles the year before last. However, given the time of year, I don't know whether or not turtles would be available to them. This is a night time shot, captured via IR.

Happy holidays, everyone!

Recently we have been asked by the USFWS to install some falcon nest boxes on cliffs in pool 13 upstream of Clinton, IA. We have not studied the cliffs in this region of the river as most of the bluffs in this region do not have road access. We have used boats to survey cliffs near Petosi, WI and Balltown, IA in the past but, to extend the boat surveys down to pool 13 would take days on the water. We called upon Dairyland Power Cooperative for the use of their Bell Jet Ranger helicopter and, pilot. Fortunately, our request was granted.

I met John Thiel at the La Crosse , WI airport early last Wednesday 4/21/10 and we set off in the helicopter with high hopes of finding new cliffs with nesting falcons. The first cliff we decided to study was Goose Island bluff just downstream of La Crosse, WI. We have had two reports in the last week of a falcon staffing a hawk and an eagle a short distance away from the cliff itself. We were curious to find out if there was another cliff besides the Goose Island cliff that these falcons could be defending. We did not find any bluffs nearby other then the main wall of the Goose Island cliff itself. Fortunately, we have a supporter of the falcon program who owns this cliff and is closely watching for falcons to take up ownership.

We then crossed the river to the Iowa side and began heading down stream. When we passed over Dead Cow Bluff south of Lansing, IA I could see an adult falcon in the cliff mounted nest box. We did not spend time at the Lansing Power plant cliff or Leo’s Bluff, where we know there are falcons on site. Due to the early morning light on the east facing cliffs we stayed on the Iowa side of the river, working our way down to pool 13. We did find some small cliffs near Sabula, IA that might attract falcons if a nest box was available. When we could just see the town of Clinton, IA coming into view we crossed the river and began checking the cliffs in Illinois and Wisconsin side of the river. We did find a string of small cliffs directly across the river from the John Deere plant near Dubuque, IA. We also looked very close at the cliffs on the Wisconsin side of the river directly across from Balltown, IA. One thing that John Theil and I noticed is that most of the cliffs in this region of the river are much smaller than the cliffs upstream. We also noticed that the rock walls had very few if any ledges or potholes.

We did not find any new cliffs with territorial falcons but we were able to get a feeling for just where we might have cliff nesting falcons in future years. One highlight of the flight day was when heading back to La Crosse, WI we decided to take a short rest at Capoli Bluff south of Lansing, IA. Raleigh Buckmaster gave us approval to land on his property. Raleigh then took my place in the helicopter to show the pilot and John Theil the falcon effigies on his land. Raleigh took the attached image of us in the helicopter when we called it a day and returned to La Crosse to tuck the fantastic flying machine away in its hanger.

The larger cliffs that we have upstream from Prairie du Chein, WI and Waukon Junction, IA are probably more attractive to nesting falcons over the much smaller cliffs found in pool 12 and pool 13 of the Mississippi River. However, last year Christian Hagenlocher, a student at Principia College, discovered a cliff nesting pair of Peregrine falcons on a tall cliff near Alton, IL. Neil Rettig also saw these same falcons early last spring while on his way to a film shoot. It sounds like the limestone cliffs begin to increase in height again in this region of the Mississippi River. It’s going to be interesting to hear if this pair of falcons returns to nest again this year and also if any new cliffs in this region come on line.

I am most appreciative of Dairyland Power donating the use of the Bell Jet Ranger to assess and GPS the river cliffs. This is the second time that we have used the Dairyland Power helicopter to survey the Mississippi River cliffs. On this second flight we used over 100 gallons of expensive jet fuel. Many thanks to Dairyland Power Cooperative for their most generous donation to Peregrine falcon studies along the big river.

Sunday 4/18/10 falcon survey on Mississippi River



I set off early Sunday morning and made my directly to the Agri-Bunge stack house in McGregor, Iowa. I searched the usual spots the adult male falcon has been known to use without locating him. I humped my telescope and tri-pod up the nearby bluff to get a view directly into the nest box mounted to the roof of the stack house. What a physical way to start the day by trudging up this bluff! Once top side and scope set up, I could easily see the head of an adult falcon incubating in the nest box.

Next site was Leo’s Bluff near Waukon Junction, IA. As I was nearing the area directly below the cliff, I saw the adult male falcon heading out over the river with a snapping wing beat. I knew he was on a hunt. By the time I got my car pulled over I lost sight of the hunting falcon. He returned about five minutes later without prey. I was setting up my scope to verify band status when a Red-tail hawk flew directly in front of the cliff face. I thought Why is this guy not getting hammered? Just then, the adult male falcon struck the hawk with such force that I could hear the strike and saw many feathers flying. The falcon got in one more strike before the wounded hawk made it to safety in the trees.


I then drove to the Lansing Power plant cliff and saw an adult falcon perched on the new cliff mounted nest box. We installed this nest box about ten feet above the favored ledge. Each and every time the falcons nest on this ledge and not the nest box their eggs are eaten by raccoons. However, I noticed fresh mutes on the ledge and now wonder if the female is on eggs on the ledge and the adult male falcon is using the nest box perch as a sentry spot. I will need to access the roof of the plant turbine building or cat-walk up on the stack to get a good view of the cliff nest box and nearby ledge.


The nest box we mounted about nine years ago on Dead Cow Bluff just upstream of the Lansing power plant had an adult falcon perched out front of the nest box. David Litton, Tom Griffin, Dave Kester, Neil Rettig, Maggie Jones, and myself mounted this nest box. Humping the nest box, pea-gravel, tools and ropes to the top of this bluff took a bit of effort. However, after all of these years, it appears it was an effort worth while.


I checked Blackhawk and Reno Bluffs without finding falcons. I spent about 30 minutes at the Shellhorn cliff south of Brownsville, MN without locating a falcon. I did not find a falcon at this cliff on my last survey and now feel that the adult falcons that were on site in mid March have moved elsewhere.


I saw one falcon at Great Spirit Bluff perched on a dead snag close to the nest box, and one adult falcon strafing a Turkey vulture at Queen’s Bluff. I spent quite a bit of time at the cliff south of Homer, MN where on previous trip I observed a falcon. No falcon on this trip. I spent quite a bit of time at Homer Cliff north where we have had successful nesting before but no luck in 2009 or again in 2010.


I originally had planned on making my way to Red Wing, MN but was anxious to meet with Gary Grunwald at Twin Bluffs near Nelson, MN. I crossed over at Winona and spent some time at Castle Rock without finding a single falcon. No falcons seen at Fountain City, WI.


The falcons at 12 Mile Bluff are seen more often on the cliff then at the nearby Dairyland Power nest box up on the stack. John Thiel was able to get the band number of the adult male who is a falcon named Mark (23/M), a 2002 HY falcon from Castle Rock


Maassen’s Bluff has no falcons at all this year. This is very strange, since we have had adult falcons at this cliff for many years. Whether or not they successfully produced young, we've had an adult pair on territory for a long time. Not this year, though.


I met with Gary Grunwald down below Twin Bluffs at Nelson, WI. After waiting for about 30 minutes, we saw an adult male falcon chase off intruding vultures. He then flew to a live cedar tree and disappeared. Gary and I next made our way to Maiden Rock and quickly located an adult male falcon that is banded but I don’t think it is Gunnar, the captive bred falcon that has nested at this cliff in the past. We didn't find a falcon at West Bluff, although the land owners have reported seeing two falcons drive away eagles.


Gary and I made our way back down stream, stopping for a few minutes to try to get the band number of the adult male at Maiden Rock (no luck). We ended the day at Twin Bluff, where we were shocked to find vultures flying across the face of the cliff and even perching on the bluff top without being harassed by a peregrine falcon.


We have had adult falcons at these cliffs in past seasons that do not have resident falcons this year:

• Castle Rock, WI
• Masssen’s Bluff,WI
• Homer, MN cliff
• Fountain City, WI cliff
• Shellhorn cliff, Brownsville, MN

Bob Anderson

Greetings, I had received a report of a falcons stooping on a Red-tail hawk near Goose Island cliff south of La Crosse, WI. On Saturday I gave a presentation in La Crosse then set off to check out the falcon report. As I drove near the cliff, I could see the cliff owner standing in his yard looking up towards the Goose Island cliff. He has not seen falcons.


I then checked cliffs on the WI side of the river and crossed over at the Lansing, IA bridge. Made my way to down below Dead Cow Bluff and was pleased to see an adult tiercel falcon perched on a dead snag near the cliff mounted nest box. All looks well at this site.

I then drove to the Lansing power plant cliff and hiked to the area directly down below the cliff face. I was pleased to see an adult tiercel falcon perched on the new cliff nest box. We mounted this nest box a few years ago in an attempt to attract the nesting falcons away from their favored ledge where each and every time they have attempted to breed on this ledge the eggs/young were eaten by raccoons. It's looking promising for this pair to be productive since raccoons can't access this nest box.

Things look good for the nesting falcons at the RRP nest box on the Agri-bunge stack house in Mc Gregor, IA.

The cliff nesting pair at Leo's Bluff near Waukon Junction, IA are probably on eggs.

The adult falcons at Larson's Bluff near Lynxville, WI are looking like they will use the main cliff this year. With the nesting falcons at the Dairyland Power Genoa plant and the other nest sites mentioned above, we have six pairs of nesting falcons in a relatively small area of the Mississippi River.

John and I will be checking all of the cliffs near Petosi, WI and Balltown, IA in a helicopter this next week. We will also check for occupancy at the cliffs in pool 13 upstream of Clinton, IA. All of these cliffs do not have roads nearby and to survey by boat would take days. Look for a report of cliff assessment and GPS coordinates later this next week.

Some of the birds we watched have really struggled this spring. They face many challenges, including weather (the snowstorm at the Fort St. Vrain nest as the first eaglet was hatching), other birds (territorial battles at the Valmont owl nest and Red Wing grain elevator), and, especially in the case of cliff-nesting birds, other animals. Yet they persevere. Both eagle eggs at Fort St. Vrain have hatched and the young eaglets seem to be doing well despite the horrendous weather. Looking at this image, you wouldn't guess the nest had been covered in snow just a day or two before. The owls at Valmont appear to be ready to recycle and lay a new clutch any night now. The Horizon Milling female, Lolo, has laid her second egg. Hatch will be in roughly early May - I'll give a better date for that once egg three is laid. And at the Raptor Resource Project we are, among other things, conducting river surveys and getting ready for banding season.

My children and I went down the Mississippi River on the WI side yesterday to look for peregrines. We started at Diamond Head Bluff in Diamond Head, WI. We didn't see any peregrines there, but we did see 15-20 of what I think were broadwinged hawks kettling over the bluff. It is a wonderful time to be on the river right now - the floodplain is brimming over and everything is waking up!

Moving on down the river, we saw mature and immature bald eagles, red-winged hawks, pelicans, ducks, and beavers. We were unable to survey the Bay City bluff - I think that will need to be done by boat, or possibly hiking - but we did see a female peregrine flying in the vicinity of West Bluff. We spotted a male and female at Maiden Rock. This year, she was sitting in a dead snag to the north of last year's eyrie, roughly in the black circle area. I don't know whether she'll stay there, but she did explore a pothole in the area while we watched her.

Next, the children and I went to Twin Bluffs in Nelson, WI. We did not see peregrines there, so we went to say 'Hi!' to Gary Grunewald and check out Maasen's Bluff. It is a good thing Gary is handy, because Rebekah locked my keys in the car, and he had to break in to get them. You can break into a Saturn with a long piece of wire and a little patience. Thanks, Gary! Gary also told me he had not yet seen or heard peregrines, but we maybe saw a male peregrine right before I left. That bluff will need a harder look.

There were no falcons present at the Alma Marina cliff, although the lone pothole had fresh whitewash. This could be from birds other than peregrines, however - a GHO has nested there in years past. We saw a female at 12-Mile bluff behind the Alma powerplant. I cannot tell you how happy I was that she appeared to be exploring a completely new pothole on the bluff. That old pothole was a bear to get to! If she picks this new one - it is high up on the 'point' of the bluff, as seen from the north - it should make things easier.

I didn't see any falcons in Fountain City or, to my disappointment, at Castle Rock Bluff. I sat at Castle for 15 minutes, scanning the bluff and sky and checking all of the usual perching places. Nothing. However, Maggie Jones reports falcons at Lock and Dam 9 and Lynxville, and the season is young yet. Possibly the bluff will fill up yet!

If you see falcons in Fountain City or at Castle Rock (or anywhere else along the Mississippi between roughly Red Wing and southern Iowa, in any of the states), please drop us an email: ries93@gmail.com. Thank you, and happy birding online and off!

As our readers know, the falcon Bella died of Frounce earlier this week. Bob and I were scheduled to go up to Cohasset to band, but he stopped at GRE and removed the dead falcon. Brenda Hoskyns took it to the Raptor Center, which confirmed Bob's diagnosis of Frounce and gave her Spartrix to treat the rest of the clutch.

According to The Modern Apprentice, Frounce is "a highly contagious yeast infection of the digestive tract. Frounce is caused by a protozoan called Trichomonas which is frequently present in the crops of pigeons...The typical signs of frounce are white spots in the mouth or crop, often described as "cheesy" or "white plaques." These alone are not enough to diagnose frounce, but it is one hallmark of the disease. Other signs are head flicking, difficulty breathing, or even regurgitation of food. Green mutes may also appear."

Here's a photograph from The Modern Apprentice (who credits it to Eileen Wicker of Raptor Rehabilitation of Kentucky). The yucky white stuff on the lower mandible of the great horned owl is characteristic of Frounce. It looks like Thrush, a yeast infection of the mouth that human infants can get.

Think about how quickly young falcons grow. By the time they are roughly 40 days old, they've reached their adult size. They've increased their body weight over 10 times, grown two new coats of feathers (a second down coat by 10 days and flight feathers by 40 days), and gone from mostly huddling under a parent through walking, practice flying, and real flying. Bob believes that this is a very stressful time for them, which makes them more susceptible to Frounce. Furthermore, this accelerated growth rate requires a lot of food. Anything that interferes with a growing falcon's ability to eat will quickly impact it. As PLoS states, The conditions an organism experiences early in life can have critical impacts on its subsequent health and well being, both over the short and long term. Since a falcon's 'early in life' passes pretty fast, events and conditions can very quickly reach the critical point.

At any rate, we drove to Grand Rapids on Wednesday night. Minnesota Power put us up for the night and we banded at the Cohasset plant in the morning. The weather was cloudy and cool - perfect for a stack climb. I discovered this year that rests are better taken on the fall gear and not the ladder enclosure - those harnesses are almost as comfortable as an easy chair when you hang in them. Here's a video of the banding. We were joined by Darryl Councilman, a MN Power employee who got the nestbox installed, and Swede, another MN Power employee who has been a real champion of the Peregrine-utility project. The babies were healthy and both parents were unbanded. I banded them - I've been getting a lot of practice - and drew blood. The trick is to have a nice big vein, someone who can keep the falcon still, and the ability to disconnect the worrying part of your brain from your hands, which need to be worry and shake-free.

We left Minnesota Power, picked up my children in North Branch, and drove to Elk River to treat the rest of the GRE nest. Last year, three of four young falcons in Duluth died after eating a bad pigeon. We didn't want a repeat. We were met by Brenda Hoskyns and another GRE employee. They took us up to the roof, where Bob and the other guy tied off and got the falcons. Brenda and I held them while Bob gave them pills. Brenda had the great idea to bring some water up to help wash the pills down. After Bob got the pills in the back of the falcons' throats, he sprinkled some water from his fingers into their open mouths. This helped lubricate everything, and the pills went right down. One of the falcons had Frounce lesions in its mouth, so this treatment saved at least one more.

We'll banding the King Plant and Highway 95 Ospreys the week of July 6th. I'll provide more info when I have it. I'm hoping to learn pole spiking before then...

Here are some random banding pictures - enjoy!



Bob and Jeremy on Maiden Rock. It's nice to get a good ledge! This was Bob's 100th rappel on a river cliff. The rock was somewhat loose here, so the overhang was also welcome. That big rattlesnake? He was maybe 50-75 feet overhead, sunning on the edge of the drop.



Ben on West Bluff. He climbed into the eyrie to get the baby falcons.



The eyrie at West. This is an excellent place for baby falcons - very, very hard to reach! Ben balanced on a ledge, Bob lowered the sky kennel to me, and I swung it over to Ben. He loaded the baby falcons out and very, very gently let the kennel go. Bob raised it and I helped get it past the overhang. This is a three-person site for sure.

Looking up Lake Pepin from West. There were miles of sky. This is one of the prettiest views I've ever seen.

Me at West, watching Ben do all the work. It wasn't until after I was hanging in space that Bob told me I was just where Dave had almost severed his rope last year. At least I wasn't trying to swing into the eyrie.


Eyrie at West, outlined in red. Ben rappeled down the crackline to the left and eased over the ledge to get to the eyrie. I was stationed under the overhang at the above right of the eyrie.

Any excuse to go to Duluth is good, but peregrine banding is my favorite! This year, Elizabeth, Rebekah, and Isaac joined Bob, Jeremy, and myself at Greysolon Plaza and Minnesota Power and Light's ML Hibbard plant.

We started at Greysolon Plaza, where Julie O'Conner and Crew from Hawk Ridge had spotted three babies in the box. A crew from Venture North had showed up to film the event, so we decided to band the babies inside the Greysolon Building. Bob, Jeremy, myself, Miriam, and photographer Michael Furtman went up to the roof, while everyone else stayed downstairs. This was a good thing, since Amy the falcon was in fine form. She started strafing runs almost as soon as we got up on the roof.

Bob, Jeremy, and I got the window washing rig (all the tires had air!) and pushed it over by the nestbox. Rigging up to go over a wall is a little different than rigging to go over a cliff, especially when Amy is on the attack. In this case, the anchor is set around two eyebolts attached to the rig. The rope goes straight up the middle, through a gap designed to allow it to pass. So, you set the anchor, pull the rope through, climb to the top of the rig, and attach to it to your grigri while ducking the falcon. These photographs are from Michael Furtman's excellent website. I'm going to be buying some prints.

I got all that done, and went over the wall. I'm used to having a rope bag attached to my leg, but in this case, the forward and tag ends of the rope are both going back down - one to the anchor and one to the bag, which sits on the roof. It is very, very important to make sure you have your hand on the tag end of the rope, not the anchor end. Normally, this isn't something you have to think about, since the rope bag makes it real easy to remember, and you usually have a chance to get good and on the gear before going down, and a falcon isn't attacking you while you rig. But you do have to take care here.

I position to the side of the nestbox and whap, Amy hits me. Head down and whap, Amy hits me. Quick look up to see where she is. Ah, circling back for another run. I reach in the box and grab baby one - maybe 17 to 19 days old, the perfect age for banding. Into the box she goes. Whap! Amy hits me. It's a good thing I shop at Target, since she ripped up the left shoulder on my tshirt - possibly just seconds after this photograph was taken. I love this falcon!

We also had a very nice surprise - there were four babies in the nestbox this year! After last year's experience, when all the babies but one died from Frounce, this was a great thing to see. I got all of them into our sky kennel, Jeremy and Bob pulled it up, and we took them down into the building. We were in a hurry, so Bob banded.

It was hot and we didn't want to put the babies back in the kennel, so we had some volunteers sit, with their legs in a big circle, and mind the babies. I'm not sure who the adult is. The children are Isaac and Elizabeth. Rebekah also minded a falcon, whom she nicknamed 'Screech'. Screech was the vocal one of the group. Elizabeth, my oldest, announced afterwards that she wants to begin coming with and helping. I'm glad she had fun - I'm glad everyone had fun! It was wonderful to see these healthy young peregrines. Make sure to visit Julie O'Conner at PeregrineWatch on the Lake Walk in Duluth - watching these guys learn to fly will be quite a treat!

After Greysolon, we headed for the Hibbard Plant. The kids had to stay in my van here, since this is a working power plant - not a good place for children! I parked where they could watch the action, if they liked, and we headed up. Bob's shoulder was sore from Maiden Rock, so he asked Jeremy and I to go up and band. It's maybe a 75-foot ladder climb here - not too bad - on the outside of the stack. The plant provides harnesses and fall protection, which you clip into with a dynamic lanyard. However, the drop would be roughly 8 - 10 feet on the lanyard, so I have to say that I would not want to put it to the test.

The female here is the same as last year, *Y/6. She is downright polite when compared to Amy. Jeremy got the three babies one at a time and I banded them. There were two males and one female. We did not draw blood - I've drawn twice this year (successfully, both times!) - but it was windy and I was nervous. I'm going to get a bag of needles and practice on oranges over the winter. That's how they do it in nursing school.

We got back down and that was the end of it. Total: 7 baby peregrines banded in Duluth, 1 ripped shirt, and 1 very, very good day.

Is it just me, or is it funny that the word verification to post this blog was preen.

You know you've been to a lot of falcon bandings when everyone ignores the banders to take pictures of the rattlesnake sunning itself just 40 feet from the drop spot.Of course, the snake was as thick as a baseball bat. Then again, you know you're in a crowd of nature enthusiasts when one person yells "Rattlesnake!", and everyone else runs toward him.

We banded at four sites on Tuesday, June 9th: West Bluff, just north of Maiden Rock, Maiden Rock, 12-Mile Bluff, right behind the Alma power plant, and Bay State Flour Milling in Winona, MN - my first flour mill! The crew consisted of Bob Anderson, his son Jeremy Anderson, Ben Ogren, and Amy Ries. We were joined by a number of people, including John Dingley, Gary Grunwald, Doug Wood, John Thiel, and several others.

We started right in with West Bluff. Ben Ogren, Bob, and I looked at West from down at the bottom. This is the cliff where Dave nearly severed his rope last year attempting to swing into the eyrie. Ben decided he would rappel down and climb into the eyrie instead. I would drop with him, get him the kennel, and provide whatever support I could. Let me explain something for any climbers that might be reading this - we weren't rigging for climbing on a dynamic rope, but for rappeling and working on a static rope. For you nonclimbers, the shock of a fall on static line is taken by your body and anchor, not the rope. Static falls can break bones, severely damage tissue, and break or rip out gear and anchors. It was critical that Ben avoid falling.

We got up to the top and I dropped to age the babies. Just as I got under the overhang, Bob said, "Oh, by the way, that's the spot where Dave almost severed his rope last year, so be careful." I avoided a clever response, rappeled down to the eyrie to age the babies (age: okay for banding) and kicked back to watch the Ben Ogren show. After all, the Boss had told me to be careful!

Ben got over the edge just fine (he's experienced), but had a brief moment of losing it when he got into position for climbing over to the eyrie. Our look from below completely failed to convey the sketchiness of our placement, the sheer and utter crappyness of the loosest, most brittle rock imaginable, and the lodging of Ben's rock in a large crack that was filled with sharp edges. "How hasn't one of you died!?" Ben yelled. I yelled back something encouraging about how badly the rock sucked, and Ben asked me to tell him whether or not his foot placements were good as he eased across a narrow ledge into the eyrie. I gave him feet and hand suggestions while he climbed, managed the rope and got into the eyrie. Out of the fire and into the frying pan: I lowered the kennel, he filled it with four lustily vocalizing, footing baby monsters (peregrines), and up the they went.

West is impossibly beautiful. I hope that Ben sends me photographs for posting. It looks north towards the mouth of Lake Pepin. We were about the tallest thing around, and you could see the river valley for miles. The eyrie was large and well protected by an overhang, so the babies were safe from weather, raccoons, and (judging by the whitewash and their overall health) starvation. We found blue jay remains and spotted the head of a black bird about 5 feet below us. Blue jay remains showed up at several sites this year.

Bob and Jeremy banded the young falcons and I lowered the kennel down, using my height (I was hanging in air about 12 to 15 feet above him), to gently swing the kennel over. He grabbed it, used a daisy chain to back it up to his harness, and was again repeatedly footed while getting the babies back into the eyrie. Up we went. I had to work my way out from under a very large overhang, on gear only, while Ben had to climb back out of the eyrie and carefully take up rope until he could swing out without falling. It was quite an adventure!

We headed to Maiden Rock next. Here's a photograph with the eyrie marked. It's roughly in the middle of the bluff this year, not on the point. Bob was excited about his 100th rappel on river cliffs here - and a little worried about disturbing baseball-sized rattlesnakes after Ben spotted one. Bob and Jeremy celebrated his 100th rappel together with a first-ever father-son banding on the cliff - Bob thought the rock was a little too loose to haul the babies up, and there was a bit of an overhang there as well. They banded three healthy young falcons at Maiden Rock.

You know, I ended up setting anchors for other people this year. That's a difficult thing to do. I'll willingly go down an anchor I set, but it is hard to watch other people do the same thing - I'm much more nervous for them than I would be for myself. It was a real relief to see Jeremy come up, or hear Bob get to the bottom. The life of a rappeler is at least partly in the hands of the anchor setter. It's not easy to get used to.

We pulled up gear and headed for 12-Mile bluff, a big crumbly bluff behind the Alma power plant. They were nesting in the exact same spot they nested two years ago - a hole way down the wall, almost even with the treeline. I climbed through the dead snag from hell, tossed all the loose rock I could see from the top of the bluff, and rappeled through a cedar tree down to the first terrace, where I sheltered under an overhang until Jeremy joined me. I went down another eight to ten feet to get the babies. There were four healthy youngsters in a small hole sheltered by an overhang. Had the parents nested on the ledge above, the babies would have been eaten by racoons - there was racoon poop all over! They were safe and well fed here, however. The prey remains were well picked over and not real obvious to me, but I believe I saw some warbler remains, judging by the size of the feet and the cliff's location on river bottom land.

Bob got the kennel up through the cedar tree and the snag. They quickly banded the babies and dropped them back. I earned a few footings but got them into the eyrie and Jeremy and I headed down the cliff and on to the talus. As nasty as that was, neither one of us was interested in climbing back up through the cedar snag. This bluff also has a lot of loose rock, which poses a very real danger to humans and young falcons alike. The less disturbance, the better!

We took a quick break to try to get band numbers while we watched the male peregrine eat a pigeon. I'm glad he got dinner, since we went straight to Bay State Milling in Winona. About 10 years ago, a girl named Maggie Lubinski put a nestbox on the roof of Bay, where her father works, as part of a 4-H project. The box sat mostly empty until this year, when two falcons nested there. The adult female is Chicklet, a 2005 hatch from Dairyland Power Genoa. We don't know who the male is yet.

Bob, Jeremy, Doug, the plant manager, and a plant employee all headed up to get the falcons. We needed hairnets, a beardnet (for Bob), and special harnesses to stay safe on the roof. We loaded three babies into the kennel, brought them down into the plant's entrance, and banded them for everyone to see. There is a nice story about it here:

http://www.winonadailynews.com/articles/2009/06/10/news/05raptors0610.txt

It was a good day on the river.

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