Wednesday, October 15, 2014

When will Mom and Dad...

When will Mom and Dad work on the nest? When will Mom and Dad mate? Are the eagles in Florida going to lay eggs early? "What's going on?!" everyone seems to be wondering.

Mom and Dad are on Eagle Time, which makes their behavior a little harder to pin down by our own clock! Still, their past behavior provides some clues. We should see work on the nest beginning in October and accelerating through the end of the year. In January, the eagles should move deeper into courtship. In addition to nest-building, we should see pair perching, vocalizations, bill stroking and pecking, and some footing or body stroking. Towards mid-to-late January, the eagles should begin bringing soft nesting material such as grasses, corn husks, and corn stalks in to line the nest bowl. Dad will begin sharing food (sometimes reluctantly), and physical contact will accelerate with even more touching, footing, and beak kissing. Mating will most likely begin in late January or early February, followed by egg-laying in late February or early March,

The US Fish and Wildlife Service's Bald Eagle Management Plan has a chronology for nesting activities in various parts of the United States.

Northern US. Includes Decorah, Fort St. Vrain, MN Bound

Southeastern US. Includes Florida Eagle cams, Berry College

As the chart clearly shows, the bald eagles in the Southeastern US are running on SEET (Southeastern Eagle Time) when compared to bald eagles in the northern US. However, eagles in both regions are right on time for their behaviors. In Iowa, Colorado, and along the Mississippi river in Eagle Valley, eagles are beginning to visit and work on nests.
If you can't keep up with the nests live, you are welcome to visit our Facebook page and/or forum.

The US Fish and Wildlife Service website contains some very good information on BE nationwide. Go to http://www.fws.gov/midwest/eagle/conservation/baea_nhstry_snstvty.html for a live web site or http://www.fws.gov/midwest/eagle/pdf/NationalBaldEagleManagementGuidelines.pdf for a .pdf of the management guidelines.

Monday, September 29, 2014

Four and Dispersal

Four back in Decorah. Photo credit Bob Anderson.
Last week, Four took a little trip 22 miles northwest of her natal nest, although she has since returned and reconnected with Mom and Dad. What was Four doing? Will she ever permanently leave Decorah? How do we define and classify the behavior of a highly nomadic species like the bald eagle? I can't tell you what Four is thinking, but I can tell you a little bit about eagles and their movements.

Dispersal is the movement of individuals from their point of origin (natal area) to where they reproduce or would have reproduced had they survived and mated. Navigation is an animal's movement around its territory or home range. Migration is the regular, seasonal movement of animals between breeding and non-breeding areas. While D1 hadn't yet bred, she was clearly migrating back and forth between a non-breeding territory (Polar Bear Park) and a territory in which she would be likely to breed (NE Iowa).

It is theorized that animals disperse for one of three reasons:
  • To avoid inbreeding
  • To avoid kin competition
  • To colonize new habitat
A detailed discussion of these theories can be found here, but all three dispersal strategies are linked to reproductive success. Inbreeding takes a toll on reproductive fitness in the long run, and kin competition can have immediate deleterious consequences, especially if kin are competing over limited resources. Colonizing new habitat disperses a population across a wider area, so local extinctions have a lower chance to kill every individual in a population.

Having said that, D1, D14, and Four didn't sit down and check off a list of reasons prior to dispersing. Dispersal seems to be triggered by a number of factors, including hormones, body condition, reduction of parental provisioning, increased locomoter activity, and external factors that include favorable winds and full moons for night flyers. In short, our eagles learned to fly and hunt, Mom and Dad decreased feeding, an adrenally-produced hormone called corticosterone soared, and the eagles dispersed. Reports of Four and the other eagles playing 'tag' with Mom and Dad shortly before dispersal may really have been a hungry, hormonally-charged young eagle chasing down its parents in an attempt to secure food from them. Suddenly tag seems a little less playful.

Unlike dispersal, migrating animals usually move from one geographic region to another without using intervening habitat.  But are dispersal and migratory behaviors mutually exclusive in an highly nomadic animal that usually doesn't breed until it is four years of age or older? What limited data we have indicates they aren't. D1's first year had characteristics of both dispersal and migration. She left her natal territory on August 13, 2011 and flew 262 miles northwest, arriving at her northernmost destination on September 6th. She spent the next four months slowly traveling south, with long layovers at Yellow Lake and Black River Falls. She arrived back in NE Iowa on December 24th, 2011.
D1 in 2011
D1 spent her winters navigating throughout NE Iowa and SE Minnesota, but she refined her north/south movements considerably. By 2014, her 808-mile trip north to Polar Bear Park took just 16 days. Although she wasn't yet breeding, her trips fulfilled the criteria for migration: they were seasonal, endogenously controlled, and didn't use much intervening habitat.

RRP board member Brett Mandernack is researching the migratory behavior of immature bald eagles. If there is a difference in immature vs. adult eagle migration, when does this change occur? Is it gradual over the first several years of the eagle’s life or is the change abrupt? D1, D14, and Four are part of his work. The paper from his first study, which examines data collected between 1999 and 2006, was published in the Journal of Raptor Research in 2012. An abstract can be found at http://dx.doi.org/10.3356/JRR-10-77.1

So will our eagles choose to nest in Decorah as adults? It's not impossible, but it isn't likely either. Dispersed young may return to the vicinity of the nest, but they don't appear to spend time there as sub-adults or adults. A study of 878 bald eagles found a median natal dispersal distance of 42 miles (69.2 km) overall, with females dispersing farther than males. Unlike human families, the young do not return for a visit with grandchildren in tow.

Eagle cluster map. Decorah is marked by the red 375, but note other favorite spots
Does an eagle's initial dispersal or overwintering perambuation tell us where it might nest as an adult? D1's favorite wintering area was near Elkader, Iowa, about 35 miles south of her natal nest - in line with average disperal distances. Unfortunately, her transmitter stopped talking to us. We'll try to get a visual on her this winter but we can't guarantee it.

As I mentioned at the beginning of this post, Four is back in Decorah and reunited with at least one parent, although we haven't seen them feeding her. We'll let everyone know if she leaves again.



Things that helped me learn about this topic:

Thursday, September 18, 2014

Flight Maps

Will Four ever disperse? We've been asked that question via facebook, email, and our forum. Only Four can answer that question, but I thought it might be worth looking back at D1 and D14 for clues.

D1's first flights, 8/01/11 to 8/12/11
The map above shows D1's first flights. She fledged in June, at 81 days of age, and we attached the transmitter to her on July 18, 2011. The maps shows her exploring her natal territory, traveling simple, short back and forth paths as she learns proficient flying, food-finding, and navigational skills.

D14's first flights, 8/01/12 to 8/12/12
D14 was 78 days old when he fledged in late June, He is less centered around the nest and hatchery than D1 was, but his initial exploratory flights are very similar. Like D1, he is flying short, simple back and forth paths as he gains skill and experience. 

Four's first flights, 8/01/14 to 8/12/14
Four's fledge occurred at approximately 76 days old, in late June. Like D1 and D14, her early flight pattern is relatively simple  - a lot of short back and forth explorations. Her first "loop" occurred on August 10 and was just 1 mile long (.5 miles out and back). 

So when does a hatch year eagle stop exploring and start dispersing? D1 was quite obvious. On August 13 2011, she flew north 14 miles toward the Iowa/Minnesota border. By September 6, she was 262 miles north of the nest. She turned south and came back to Decorah, arriving back in NE Iowa on December 24, 2011. Before leaving on August 13, she had never been recorded more than .98 miles from her natal nest.

D1's 2011 dispersal
The map above displays D1's entire dispersal. On August 13, she went from local travel along simple paths to long-distance travel along more complex paths. Her large loop included several smaller loops with fewer of the simple back and forth flights that we saw her first weeks on the wing.

D14's 2012 dispersal
Unlike D1, D14 spent more time flying around the Decorah area and left town twice: once on September 5, for a 24-mile flight south, and once on September 22, for good. So did he disperse on September 5 or September 22? My money is on September 22. D14's movements seem to indicate a higher degree of pre-dispersal restlessness, but he didn't leave permanently until September 22. Like D1, he went from local travel along simple paths to long distance travel that included looping flight. Unfortunately, he died of electrocution on November 6 near Rockford, Iowa. The loss of D14 was tragic for personal and research reasons. Everything we could have learned from him ended in his premature death.

As their flight paths show, D1 and D14 spent some time acquiring skills and strength before dispersing. They needed to be able to fly strongly, work with the wind, find food, and navigate. We have recently begun seeing some increased complexity and distance in Four's flights. Only time will tell if and when she disperses, but Four's flight paths and recent calf-eating excursion seem like good signs. Stay tuned! You can make your own D1, D14, and Four maps here: http://www.raptorresource.org/maps/personal.php

Four, 9/1/14 to 9/17/14

On Migration

At whatever moment you read these words, day or night, there are birds aloft in the skies of the Western Hemisphere, migrating. If it is spring or fall, the great pivot points of the year, then the continents are swarming with billions of traveling birds...
- Living on the Wind: Across the Hemisphere with Migratory Birds

We get a lot of questions about migration. Do the Decorah eagles migrate? Do our Peregrine falcons migrate? Where do they go when they leave? We fitted our eagles with tracking devices in part to help answer some of these questions. To date, we've learned D1's migratory paths and summer and winter ranges, observed an interesting difference in dispersal patterns between D1 and D14, and an interesting similarity between D14 and Four. 

I used to think migration was very simple. Like a lot of people, I thought that all birds except chickadees, pigeons, crows, and woodpeckers migrated once it got cold. They went south to escape snow and ice, returning to nest when the weather warmed up. 'South' was anywhere it didn't snow, or at least didn't snow much: Georgia, the Gulf Coast, South America. I had no idea that many birds don't migrate, or that 'south' could be Minnesota or Wisconsin. Peregrines, Snowy Owls, and Bald eagles taught me otherwise.

Among birds, migration is the regular, endogenously controlled, seasonal movement of birds between breeding and non-breeding areas (Salewski and Bruderer 2007). Bald eagles and Peregrine falcons are partial migrators - that is, some members of the species migrate and others don't. This is the most common type of migration, which makes sense since migration is driven by a number of factors, including daylight length, food availability, weather, the time it takes to raise young, and the distance between wintering and breeding grounds. Migration allows exploitation of different habitats as environments change seasonally or successionally (Dingle, 1996). Food availability seems to play a very important role in the migration of Bald eagles: inland northern Bald eagles tend to move southward after ice and snow start putting a lid over their favorite food source - fish, while southern Bald eagles are thought to move northward once warm weather drives fish into deeper water (although there is some debate about this). Weather can also impact migration timing in other ways: for example, a favorable wind pattern might help compel a bird to leave for its wintering or summering grounds if other factors are in place.

D1's looping migratory path in 2012 and 2013
I also thought that birds used to travel the same path backwards and forwards. However, it turns out that many birds, including our own D1, favor loop migrations. This pattern might be a response to seasonal prevailing winds, food availability, tradition, and/or genetic influence. More to the point, loop migrations require more complex navigational skills (and perhaps inheritances) than a simple point A to point B path.

So how do birds navigate? Migration studies have found five major methods: 
  • Magnetic sensing: Some birds, including pigeons, are able to use the direction and strength of Earth's magnetic fields to orient themselves. http://www.nytimes.com/2012/04/27/science/study-sheds-light-on-how-pigeons-navigate-by-magnetic-field.html?_r=0
  • Geographic mapping: When I'm in Minneapolis, I use a number of tall buildings to help me orient the city. It turns out that birds do the same thing, using landforms and geographic features such as rivers, coastlines, and mountain ranges to guide them.
  • Celestial navigation: migratory birds use the position of the sun (during the day) or the rotation of stars (at night) to orient themselves. Experiments done by Dr. Emlen in 1967 indicate that celestial navigation is learned. http://www.birds.cornell.edu/AllAboutBirds/studying/migration/navigation
  • Wind patterns: A recent study at Cornell using crowdsourced data found that passerine birds are heavily dependent on wind direction for migration. By shifting routes, birds take advantage of stronger tailwinds in spring and less severe headwinds in fall.
  • Learned Routes: Some bird species, such as sandhill cranes and snow geese, learn migration routes from their parents and other adult birds in the flock. Once learned, younger birds can travel the route successfully themselves.
What do Bald eagles and Peregrines do? It seems they most likely use multiple sources of information, including celestial and magnetic clues, light polarization, wind patterns and direction, and geographic cues (which would likely be highly correlated with geography). Although parents and young don't migrate together, D1 and D14 were in the company of other eagles every time we saw them, so I suspect that some degree of learning, or at least following, also plays a role. While we haven't yet seen Four in the company of eagles outside her family, she's only begun her wandering. Since young bald eagles are much more nomadic than adult Bald eagles, we hope to have several more years of watching her. 

In addition to watching our eagles, keep an eye on the animals outside your window. We know fall is here, and so do they.
  • Birds may begin gathering in huge premigratory flocks, gorging on food to build fat reserves, and exhibiting restlessness, also known by the marvelous word zugunruheThese behaviors help prepare birds for migration. Keeping a well-stocked bird feeder helps them too.
  • Juvenile peregrine falcons are on the move! You'll sometimes catch a stranger on cam as they disperse down river. Please let us know if you get any band numbers! 
  • Frogs and turtles may begin migrating from summering breeding grounds to deeper bodies of water. While their travels are short, they still fit the definition of migration. For more on frog hibernation, click here. The Minnesota DNR has a very good article on helping migrating turtles cross roads, some cities close roads, and volunteers help keep migrating frogs safe. 
  • Some insects migrate and others hibernate. Aggregating paper wasps may be getting ready to hibernate, while dragonflies migrate in large numbers (or check this source out).
  • Watch out for migrating Mule deer! According to National Geographic, they make a 150-mile migration twice yearly from the low desert to the high mountains.
Have a happy fall and take the time to watch for migrating birds and other animals! Would you like to know if the winds are favorable for bird migration in your area? Check these links out: 


Some things that helped me write this post: 
* Regarding male Peregrine dispersal: of course, there are exceptions. We released Zeus, the male at Woodman Tower in Nebraska, in Rochester New York. We were very surprised when he showed up in Nebraska. Did he fly west intentionally or was he some how blown off course or lost? 

Friday, August 08, 2014

Banding Report: Minnesota Power

From our friends at Minnesota Power. Thanks for sharing!

Amy and Matt
The three chicks at Hibbard Renewable Energy Center now have names as well as leg bands.

The youngsters, two females and a male, are Spike, Jolt and Surge. The Hibbard falcon names were dreamed up by Jodi Piekarski, supervisor, generation production at Boswell. She submitted the names Spike, Jolt and Surge, and employees selected the three as winners in a Powergram online contest that attracted a total of 170 electronic votes.

The votes were tallied today, the same day that Bob Anderson and Amy Ries of the Raptor Resource Project were in town to band the chicks born about four weeks ago. Earlier in the day, they also banded the chick born at Greysolon Plaza in downtown Duluth.

Ries, along with Minnesota Power employees Doug Braff and Matt Pohl, climbed the stack at Hibbard as the youngsters’ parents circled and screeched in alarm and news crews from WDIO, KBJR and Fox television stations watched from the roof and documented the climbers’ progress. The nesting box is on a platform on the stack about 200 feet above the ground.

Doug Braff and friend
It was a climb that only a short while earlier was in jeopardy. The MP safety crew—John Hollingsworth, Ian Wenzel and Dan Belluzzo—were checking weather conditions and monitoring lightning strikes. Fortunately, a storm that had been moving closer to Hibbard dissipated and banders were given the go-ahead.

It was Pohl’s first time as part of the banding team. He said he volunteered to help because “I figured it was a unique opportunity.” He said he rarely has climbed anything higher than the roof of his home and Tuesday’s climb “wasn’t as scary as I was expecting.”

Braff, who supports Minnesota Power’s Falcon Cams and is a veteran falcon bander, described the chicks as “feisty,” the conditions as “nice and breezy” and said the experience was “wonderful, as usual.”

Ries checked the chicks for any signs of disease or parasites and placed the bands around their legs. The bands help researchers study the movement and habits of the birds. “They look great,” Ries said as she removed her climbing and safety gear after the climb. “They’re just really nice looking falcons.”

One egg at Hibbard and the four eggs at Boswell Energy Center failed to hatch this spring, and Anderson attributes that to cold temperatures at a critical time. It was a theme the Raptor Resource Project, based in Decorah, Iowa, has seen play out at many falcon nests in the Midwest this year.

Still, even with no luck this year, Boswell is one of the most productive of the Midwest power plant sites, he said. More than 60 peregrine chicks have hatched at Boswell since 1993 and 15 chicks have been banded at Hibbard since 2008.

Contest details

Piekarski’s names received 73 of the votes cast by employees, or 42.9 percent of the ballots. Finishing second in the voting was the trio of Louie, Copper and Ace. The names Aspen, Spruce and Birch finished third in the voting. Breezzy, Chillee and Bhurrrrr captured fourth place (and last in spelling).

In her naming submission, Piekarski said her electricity-based falcon names were tied to the speed of the peregrine falcon: Spike being “a sudden increase in the amount of electricity that a system produces;” Jolt signifying “a sudden strong increase in energy;” and Surge “a sudden increase in electrical power that can damage equipment connected to it.”

For her winning entry, Powergram will present Piekarski with a beautiful 8-by-10-inch peregrine falcon print.

Wednesday, July 09, 2014

EWOT's Electrocution

Yesterday at about 10:45, Decorah fledgling EWOT was electrocuted on a high voltage power line roughly ½ mile from the mulch pile that both fledglings have been spending most of their time on. It was reported to us late in the afternoon. We collected and examined him, returning to the site of the electrocution to gather more information once that was done. Here is what we know.

The line was a 96 Kilovolt transmission line owned by ITC Holdings (http://www.itc-holdings.com/). In general, electrical delivery can be divided into two types: transmission and distribution. High-voltage transmission lines carry electricity over long distances from power plants or grids to substations. The poles or towers are physically larger and taller than those that support lower-voltage distribution lines and don’t support anything except electrical lines. Distribution lines carry electricity from substations to consumers and are supported by what most of us probably think of as utility or power poles. Utility poles are often made of wood and, unlike transmission lines, may also carry telephone and cable wires or support street lights.

ITC is able to detect fluctuations and other anomalies on their lines. When they sensed an anomaly, they sent a field technician out to investigate. He found and collected EWOT, and turned him over to the Iowa Department of Natural Resources. They saw the transmitter and called Bob to let him know that an eaglet had been electrocuted.

When we first got word of another electrocuted eaglet, we assumed it had contacted a standard utility pole. According to Refining Estimates of Bird Collision and Electrocution Mortality at Power Lines in the United States, electrocutions occur primarily at distribution lines, while collisions occur at both distribution and transmission lines. That’s certainly been our experience, since every eagle we’ve picked up has been found at the base of a distribution line. I pictured a standard wooden utility pole as we glumly drove over for our field investigation. I was surprised to instead find a high-power line between a field and a hill. We hiked out and took a look at the scene. We weren’t able to find scorch or singe marks on the pole or insulators, and the eaglet’s body was not at the base of the pole, as we’ve seen elsewhere, but under the lines three to four feet from the pole.

An examination of the eaglet’s body revealed singeing and burning around his elbow and feet. Electrocution can’t happen unless a bird’s body creates a circuit between ground and voltage, or different voltage phases, allowing energy to flow from high to low. Sitting on a wire won’t harm a bird, since it doesn’t create a circuit. But he closed a circuit with his wing and one foot, creating the flow that killed him.

In addition to singeing, the eaglet’s wing had extensive tissue damage and some severing. Although it seemed unlikely, we needed to know whether the transmitter had somehow created or closed the circuit that led to his electrocution. A quick look at the transmitter showed no damage, scorching, or discoloring. We cut the straps and removed it from EWOT’s body. The straps were intact and there was no scorching, singeing, or burning under the straps or backpack pad. Finally, we made sure the receiver could detect the transmitter. The transmitter was functioning normally, so we concluded it hadn’t been part of our eaglet’s electrocution.

Bob contacted ITC this morning. The biologist he spoke with told him that they hadn’t seen an electrocution on a high kilovolt line in the three years he’d worked for ITC. Having said that, they reported the electrocution to the U.S. Fish and Wildlife Service and the Avian Power Line Interaction Committee, and they are assessing steps that can be taken to prevent another electrocution or collision.

What we think
The pole was up to code and we haven’t had any problems at a transmission line before, so we suspect the electrocution was a terrible accident. Other electrocutions and near-misses in Decorah involved distribution poles with wonderful perching spots near the hatchery, where the eagles regularly hunt, fly, and hang out.  The transmission pole provides a bad perching spot overlooking a poor hunting ground bordered by trees. Although electrocution was clearly the cause of death, we suspect that EWOT might have collided with a wire and dropped, contacting other wires or the pole before dropping to the ground. Death was very quick.

Where do we go from here?
We don’t know whether ITC will install diverters or a similar non-collision technology over one death. Companies tend to set priorities based in large part on collisions, electrocutions, and known migration/movement paths. Reporting is key and we are very glad the company didn’t choose to sweep the electrocution under the rug.  
Bob talked to ITC this morning. If there are any more deaths, the company will report them to us, the DNR, and the USFWS.  Neither D1, D14, or Four have spent any time near the high voltage line, but if Four or D1 start hanging out, we’ll make ITC and everyone else aware of it.

Why can’t you build safe perches?
Alliant Energy, the D12 Memorial Group, the Decorah High School, and Decorah Building supply were able to make the distribution poles at the hatchery safer through insulation and safe perches. However, we’re not sure this was a perching problem and we can’t encourage perching on high voltage transmission lines since they are too dangerous. If protection is installed, it will probably be in the form of diverters that make it easy for birds, including eagles, to see the power lines.

What can we do?
Our wonderful fans want to know what they can do to make power lines safe. A few suggestions:
  • ·      Does your power company have an Avian Protection Plan? Click here for more information: http://www.aplic.org/APPs.php. Birds aren’t the only issue, either – my electrical cooperative is upgrading equipment because of squirrels! Talk to your company and find out what they have in place.
  • ·       Report electrocuted animals to your power company and wildlife agency. If your power company shrugs it off, document the problem and talk to your state’s regulatory agency. It’s my experience that most utility companies are very responsive to electrocutions. They kill animals, destroy equipment, can start fires, and are expensive.
  • ·      Learn more about the issue. A few good places to start:

While we can’t protect transmission lines with safe perches, most of our electrocutions have been on distribution lines. This seems like a good time to share the story of the D12 Memorial Group’s work with making distribution poles safer. 
We are really dismayed by the electrocution of another eagle but believe we can do better in the future. We’ll continue working with power companies to improve outcomes for birds of prey and we’ll certainly let you know what happens here. In the meantime, please feel free to share your stories of improvement and recovery with us. 

Thursday, July 03, 2014

What's up with Four (or why aren't you calling the Decorah eaglets "Dx" anymore)?

For the last couple of days, the most commonly asked question on facebook has been something along the lines of "Why are you calling D19 or EWT Four now?" We've also been asked if that means this year's fledglings are going to be referred to as D2, D3, and D4, and what this means for any other birds we've transmitted. I'll start with a recap of our EEE's:
  • Four, fka EWT or Eaglet With Transmitter, was first spotted on a road near Decorah roughly a week after fledge began. After a call from police, Bob brought her to his mews for examination and observation and fitted her with a transmitter. She has been rescued twice -- once in a corn field and another time when she was wedged against some woven wire fencing on the ground. She was the one who was relocated to the mulch pile to be with her brother EWOT/Indy. Beak depth and hallux claw measurements taken at the time we fitted the transmitter indicated that she was a female eagle. 
  • EWOT, or Eaglet Without Transmitter (aka Indy), has never been picked up and moved elsewhere. It was found at the city mulch piles about 1 mile from the nest. Bob and Brett trapped him on July 4th, attached a transmitter, and renamed him Indy. Sadly, Indy was found electrocuted on July 8th: http://goo.gl/0vjcy0
  • SOAR or Mr. SOAR is the eaglet who had surgery at the rehab facility of the same name (Saving Our Avian Raptors). SOAR (the eaglet) is recuperating and we get almost daily updates of his progress. Kay at SOAR and veterinarian Dr. Dirks believe that SOAR is a male eagle based on his size and weight. 
So why the name change? As looks and defining features change, (especially after fledge), Bob preferred to have new nomenclature established since we cannot be 100% sure of IDs. "Four" is the last number of Four's transmitter ID and WOT (Without Transmitter) was an obvious and easily identifying feature (or lack thereof) that could be used to differentiate between the two. After we attached a transmitter to EWOT, Bob and Brett renamed him Indy, short for Independence, because he was captured on the 4th of July. We don't have any plans to change the pre-fledge nomenclature of D + N, so as far as I know we'll start with D21 next year. 


I'm going to close with a quote by William Shakespeare, which seems appropriate both for its subject matter and the Bard's great fondness for falconry metaphors: "What's in a name? That which we call a rose by any other name would smell as sweet." Fly on, fledglings! You are such stuff as dreams are made on!




Citations

BA1, personal communication and information about Shakespeare's falconry metaphors.
http://www.raptorresource.org/

SE1, personal communication and facebook responses.
https://www.facebook.com/pages/Raptor-Resource-Project/103786266324668?ref_type=bookmark


TW1, personal communication and Ustream responses.
http://www.ustream.tv/decoraheagles


Wednesday, July 02, 2014

Your Top Thirteen Questions For SOAR and Dr. Dirks

Last week we asked Decorah watchers for their questions about the Decorah fledging that went to SOAR. Thanks to Kay and Dr. Dirks for answering them. Next week we'll ask for questions from Bob and Brett about development and fledge, so stay tuned!

Where will the eaglet be released?
This is a big leap to the end – IF he is able to be released… I think it would be an excellent idea to release him in the NE Iowa area. The exact location will depend a lot on the time of year. We will definitely be too late/too much time will have passed to expect that the Parents would take over any care or guidance. When the time comes we will do some consulting with our eagle experts (Bob and Brett) and find a spot where there is not a current eagle territory – just to avoid any conflicts there – usually the juvies are pretty safe. The big thing will be HABITAT – a good spot for scavenging and fishing. As we know from eagles with transmitters, eagles can travel long distances in short amounts of time. If he is able to be released, he will go wherever he wants to go. 

How do you determine where to release the birds you find, especially if they have been held for a while?
Again – good habitat is what we look for so the birds will not have to work too hard for food. We also look at time of year and weather. Winter is hard for everyone so we hold most birds late November through to early spring for release. Along with the quality appropriate habitat type, we look for travel corridors such as a river. If we release in a resident bird’s territory, which we try very hard not to do, the released bird can easily move to a new spot through the corridor habitat. 

What do you feed your eagles?
We need to mimic the things that they would be eating in the wild the best we can. This helps them to recognize what we are offering as food and is also completely nutritious. We try to give variety. Our eagles really seem to like carp – rough fish that most human anglers do not like to eat – so this helps us with donations of this type of fish. We salvage road killed deer – this meat is rich and dark – lots of vitamins and iron. We have a friend that provides some grown chickens and rabbits.

We start with hand-feeding our extremely ill patients. As they recover, they will eventually take food on their own.

The eaglet looks comfortable with humans. Does it try to bite or how does it react to handling?
A good question. Biting is involved when we need to handle him, so we have big gloves and we handle him carefully yet firmly. Overall comfort is an important part of our care. 
Most of the time our intensive care or ICU patients are in carry crates so we can limit movement. Like humans in ICU units, these birds have severe, often life-threatening injuries or conditions. We provide climate control and make sure that food and water bowls can be seen and are accessible. We also need to be able to easily administer medication and capture our patients to change bandages and perform other necessary tasks.  Of course as they feel better, they want out! When they are ready we have larger flight areas they move into for exercise pre-release. 

This little eaglet would not sit still in a crate. So he is in our small ICU room, which gives him a bit more room to move around. He is quite comfy there right now. 

What is the ICU and what does it look like?
Intensive Care is basically two large rooms and one smaller one that we heat and cool. Check SOAR’s web page for photos of SOAR facilities, including flight areas: www.soarraptors.org

How does the eaglet learn to fly and hunt absent parents?
If they are physically able to fly, they will fly. While skill is learned on the wing, flying and hunting are instinctual. SOAR has a 100 X 20 foot flight area for our eagles. After bone healing is complete, which could take approximately eight weeks or more, our patient will spend time in this large flight area with our other eagles. We have Spirit and Liberty, a bonded pair of non-releaseable education bald eagles that have fostered two different eagle chicks so far in their own large enclosure. He will not need to be fed, but they can model socialization, vocalizations, and eagle behavior. He is well past the age when he would imprint on humans, so we have no worries there. He is not going to like us no matter what!

It's my understanding that bald eagles can present unique challenges in housing and handling. If so, can you elaborate a little?
They are big and powerful. So housing requires large spaces. Handling requires experience and protective gear, including gloves, goggles, and a heavy coat. 

What particular challenges do you anticipate during the Decorah eaglet's rehab, both short term and long term?
We have crossed several hurdles. He survived his initial injuries. His fracture was not compound (bones sticking out of the skin) and was not too severe to surgically stabilize. He went through a successful major surgery. He’ll be on antibiotics to prevent infection and the next step is eating on his own. 

After about three weeks of healing, we will head back to Dr. Dirks for another x-ray to determine the amount of healing and whether or not we can remove the pin. If we can, he’ll have another three to four weeks of limited movement, but no flight attempts yet, since we need to make sure everything is solidly healed. After that, he’ll need physical therapy to get muscles into shape, and of course he’ll need to grow a tail back and we don’t know how long that will take. We will have to see how it goes/grows! 

What percentage of eagles make a full recovery and can be released back into the wild after an injury like this?
We don’t have an answer for that off the top of our heads.  We’ll have a better prognosis at the three week check up.

What is the gender of this eagle?
Judging by size, Dr. Dirks and I both think it is a male. 

Will P's recognize it and care for it or will it just be another eagle to them now?
He is in for a quite long recovery period. He will be with us too long for the parents to be in the mode of caregiving and he will be too old to need them. I don’t know if they will be able to recognize him or not.

How much of the hunting skills are learned vs instinct?
Instinct gets them started hunting and experience hones skill, since there are rewards for doing certain things and disappointment for doing others. 

Do you feel that the break in his/her humerus was due to the owl attack? 
This break is way up in the shoulder area – there is a lot of muscle around the bones there. Owls look big – but they are big puff balls – mostly fluffy feathers. These eaglets out-weigh owls by a lot.  There were no puncture wounds near the break area. I don’t think owls could have done this. Dr. Dirks and I discussed this a bit. This break would take quite a bit of trauma – like being hit by a car. But we just have no way to know for sure what happened. His feathers were grown in well enough to glide/fly from the nest, so it is doubtful leaving the nest would have resulted in this type of break either. [Amy's note: Bob made a similar observation after handling "Four", the fledgling formerly known as EWT. He also confirmed that the eaglets were developed enough to fly].