Monday, November 28, 2016

2016 by the Numbers!

To help kick-off Giving Tuesday on Tuesday, November 29, we wanted to talk about what got done in 2016. Here are the things your donations helped us get done! Please donate to the Raptor Resource Project to help us continue our work in 2017 and beyond! 

Online Interaction and Education
Since January 1, 2016, we have:
  • Provided 1,785 hours of chat on the Decorah eagles channel, including 449 hours of dedicated educational chat. Our Decorah North group provided 576 hours of moderated chat, including special coverage following the deaths of DN3 and DN2. 
  • Posted 364 times on Facebook. Topics and photos included the Decorah Eagles, the Decorah North Eagles, the GSB Peregrine falcons, the Fort St. Vrain eagles, tracking D24 and D25, Robin Brumm's trips to Decorah, peregrine falcon banding, nest box work, and many other topics related to our nests and birds. Posts were shared from Neil Rettig Productions, SOAR, the Cornell Laboratory of Ornithology, and Jim Brandenberg's 365 Nature project. 
  • Wrote 31 blogs. We addressed questions about the eagles, the nests (Is N2B big enough?), nest intruders, eaglet growth and development, the proposed 30-year take of eagles, and the deaths of DN2 and DN3, and much more!
  • Expanded our online offerings to explore.org. This ads-free site is presently one of two that streams the Decorah Eagles North channel.
I need to give a shoutout to our amazing volunteer moderators. I have said it before and I will say it again - our volunteers make our pages the best on the web and we could not provide our online educational program without their help!

Monitoring, Banding, Trapping, Recovery, and Nestbox Maintenance
Since January 1, 2016, we have:
  • Monitored over 50 peregrine falcon and bald eagle nest sites and potential territories in Minnesota, Wisconsin, Iowa, Illinois, and Colorado.
  • Banded 76 falcons at 25 sites in Minnesota, Wisconsin, Iowa, and Illinois between May 20 and June 16 - a record for us! Our northernmost territory was in Cohasset, Minnesota and our southernmost territory was in Peoria, Illinois. As always, we reported all banding and follow up data to the Bird Banding Lab and the Midwest Peregrine Society.
  • Installed 2 tracking platforms on D24 and D25 in July. Thanks to the platforms, we know that D25 was killed in a collision with a car in September, but D24 is still going strong! 
  • Retrieved DN2's body from Decorah North in May, and the unhatched eagle egg from N2B in September. DN2's autopsy can be found here. We are waiting for a report on the egg. 
  • Changed gravel at 3 peregrine nest boxes in October and November. The US Bank box in La Crosse also got a new top and we fixed the private camera at the Greysolon box in Duluth.
Thanks to our utility, industrial, and landowner partners for all of their help and support! A huge thanks to Brett Mandernack for including 'our' eagles in his studies and for sharing all of the data about their whereabouts and fates. Thanks also to David and Ann Lynch for their help with the transmitter project. We couldn't do it without all of you!

Camera Research and Installation
We focus on camera installation and nest box maintenance in September and October. Bald eagle cam work ends on October 1st, which is considered the start of the active season in our area. Peregrine falcon work can be done later since we don't tend to see much of them again until late February or early March. Even territorial falcons are less defensive of their nest sites this time of the year.
  • John Howe, Kike Arnal, David Kester, David Lynch, Ann Lynch, John Dingley, Amy Ries, Bill Heston (Xcel Energy), and Pat Donahue (also from Xcel Energy) installed a total of six cameras and four microphones at N1, N2B, Decorah North, Fort St. Vrain, and GSB between September 17 and October 16. We also provided technical support for the Seneca Nation of Indians (a bald eagle cam) and the Marshy Point Nature Center (Marshy Point ospreys). The installations took roughly 900 hours total. 
  • John Howe put in hundreds of hours researching, ordering, and testing cameras this year. While the majority of our installs are done in September and October, camera and streaming research take place year-round. In 2016, we began to move towards 4K at Decorah North and GSB - a big jump for us - and improved the audio at Decorah and Decorah North.
Other Stuff
  • We threw our annual After The Fledge party between July 14th and July 16th. Almost 100 eagle fans and volunteers had a blast celebrating the Decorah eagles and Decorah itself!
  • We provided ongoing technical support to followers who experienced problems watching our eagles, viewing Facebook, and participating in chat. Over 800 followers received support via our website, and an unknown number received support via our Facebook and Twitter.
  • We partnered with Ustream to provide temporary ads-free viewing to 347 teachers and their students.
  • John trained 4 volunteers to operate our cameras remotely - a new and very welcome step for us and our followers. 
Thank you for all of your support and for your donations. They make a difference and we couldn't continue to do it without them! 

Wednesday, November 23, 2016

A Reflection and a Thanksgiving

I found myself in an unusually reflective mood earlier this week. Today, November 23rd, was Bob Anderson's birthday. It seems like a good time to take stock of where the Raptor Resource Project has been, where it plans on going, and what I have to be thankful for.

Bob and Dave Hecht banding at Lansing in 2010
For those of you who don't know, Bob founded the Raptor Resource Project to propagate and release peregrine falcons. He was the first person to successfully breed peregrine falcons in Minnesota. MF-1, one of the first falcons he produced and released, became the first returned falcon to breed in the mid-continent following the species' extirpation in the mid-1960's. It took an incredible amount of work to keep the peregrine falcon from joining the long list of species that will be mourned on the remembrance day for lost species. I am thankful that the peregrine falcon is still with us. Where we have a will, we have a way.

I am thankful to have met Bob. He responded to an ad my little writing business was running back in 1994. I began by writing grants, but very quickly moved into field work. Did I want to attend a banding and take pictures? Yes! Did I want to hold falcons? Yes! Did I want to rappel? Yes yes yes! The writer William Least Heat Moon said in the Wonsevu chapter of the book PrairyErth that "I'm not sure what to make of it, but I think a dream can set you on another path." Bob's dream of restoring the peregrine falcon set many people's lives on another path.

Banding at Xcel's Allen S King plant in 2005
Believe it or not, we moved into internet cameras almost accidentally. Bob set up several local monitors so that power plant employees and visitors could watch peregrine falcons. If I remember correctly, Mike Miser from the Allen S. King plant in Oak Park Heights, Minnesota, suggested putting their camera online. 'Mae's Internest' hatched in 1998, making Xcel Energy's corporate website the busiest in the world for the first quarter of 1998. It uploaded a still image of Mae's nestbox every two minutes...a technical triumph at the time! That year, we also began a three-year study of heavy metals in utility falcons with the Electric Power Research Institute, Xcel Energy, and Dairyland Power. We worked with Dan Orr and Ken Mueller at Xcel Energy and John Thiel at Dairyland Power. All three men have since retired, but the paper can be found here: https://www.raptorresource.org/about-us/annual-reports-and-papers/. I am thankful to have worked with the fine men and women employed at America's power plants. The utility-peregrine program is an example of the ways in which humans can support wildlife even in the unlikeliest of areas. You guys are awesome...and great fun, too!

Bob was also working on his cliff release project. Back in 1994, he began to believe that nest-site imprinting was preventing the crossover of peregrines from power plants to cliffs. The Iowa DNR was very interested in working with Bob, so he picked up lock, stock, and barrel to move down to Bluffton, Iowa in 1996. He did a successful pilot release on the Upper Iowa river in 1997 and released a total of 19 falcons from Hanging Rock at Effigy Mounds National Monument in 1998 and 1999. The Upper Iowa hackbox can still be seen from the river, although the Effigy Mounds hackboxes are long gone. In 2000, our cliff-released falcons became the first falcons to return to the cliffs of the Mississippi. I remember going to see them quite well, since I was very pregnant with my last son. I did a lot of crazy things for and with Bob, but the only time I remember him being really worried about me was just after I huffed and puffed my way up the back of Queen's Bluff. Pat Schlarbaum's story about peregrine recovery includes information about our cliff releases. It can be read here: http://www.gladysblackeagle.org/project-ideas/longwings-return. I am thankful to have played a small piece in this story, and very grateful to the men and women of the Iowa DNR who supported Bob's work.

In 2006 and 2007, Bob was working with Neil Rettig on the movie American Bald Eagle. After the two wrapped up, Bob said "Wouldn't it be fun to put this nest on the internet?" We made Bob's dream a reality in 2009, when the Decorah Eagle Cam uploaded an image to Xcel Energy's website every two minutes. In 2010, Luther College hosted a live feed. In 2011, we moved to Ustream and the Decorah eagles became a worldwide sensation. While we celebrated the eagles, Bob also mourned the loss of his dear friend and fellow falconer Rob MacIntyre, the 'mad scientist' who was featured so prominently in the movie RaptorForce. Rob did a lot of the work on our earlier cam systems, and his death was a real blow both personally and professionally. I am thankful to have known him and his wonderful wife Jan. They brightened every room they entered.

John also likes to rappel!
While Bob never lost his drive to recover birds of prey, he suddenly had a new focus. He was deeply engaged in using our bird cams to reach learners and provide a palliative window to the outside for ill, injured, and bedridden people. Online education became a major focus, but cameras still needed to be researched and purchased, and HD was increasingly looking like the next step. Enter John Howe! John began working with Bob to research cameras and camera technologies, including solar/wireless technologies (Rob installed our first solar/wireless system back in 2003) and HD. The longer Bob worked with John, the more he was impressed. Shortly before Bob's death, he let us all know that John was to follow him as Director of the Raptor Resource Project.

This brings us up to the present. In the year since Bob's death, John has worked diligently to keep up with camera and streaming technology, deploy cameras, expand our online educational offerings, honor Bob's legacy, and secure funding (an organization doesn't run very long without money). He has more than proven himself as a director and a leader. I am thankful for John Howe and only wish that Bob was here to see the positive change that John has brought to the Raptor Resource Project.

So where do we go from here? We are sustained by our mission: to preserve and strengthen raptor populations, expand participation in raptor preservation, and help foster the next generation of preservationists. We follow our vision: to deepen the connection between people and the natural world, bringing benefits to both.
  • Education: We are looking at ways to improve and increase our educational offerings. In addition to the online interaction we already offer through our unparalleled team of moderators, we are looking at curriculum, educational videos, Skype, short movies, and other ways to reach out to learners of all age and circumstances.
  • Preserving and Strengthening Raptor Populations: We will continue to monitor our nests, band falcons, consult on nestboxes and habitat for a variety of species, provide input on conservation issues, and work with federal and state wildlife agencies to benefit of birds of prey. We are also looking at ways to strengthen existing partnerships and build new ones. How can we connect our passionate followers with organizations looking for volunteers? How can we work closer with our utility and industry partners on providing or improving habitat for the many birds that nest on or use utility land and water in other ways? How can we advocate for birds of prey? We have done a lot, but we can do more. We stand on the shoulders of giants!
  • Fostering the Next Generation of Preservationists: In addition to our online educational program, we are looking at an educational endowment in Bob Anderson's name. We will have more information about that early next year. An educational endowment seems like an appropriate way to honor Bob's legacy.
  • Connecting People with the Natural World: Researching and deploying cameras is a lot of work. Fortunately, we have a director who truly enjoys it! We will continue to do our best to connect watchers with the natural world using up-to-date, unobtrusive technology. A challenge for me: how do we develop quantifiable data from the thousands of hours of footage and anecdotes we've collected? Our knowledge has already changed since we first began watching the eagles (remember eagles are always monogamous?), but there is so much more to learn! 
So what else am I thankful for? 
  • I am thankful for fans of the Decorah eagles and our other birds. Please, keep emailing and mailing your stories and art. You have deepened our lives an immeasurable amount.
  • I am thankful for our amazing volunteers. In addition to your incredible work, my life is better for having known you. I've said it before and I'll say it again...your work makes us the best site on the web!
  • I am thankful to our Board for providing direction and guidance. 
  • I am thankful for an unexpected and unlooked for gift: the honor to be part of the Raptor Resource Project's work. My 1994 self - I was 28 years old! - had no way of knowing what saying 'Yes' to Bob's first request would lead to. Bob, we will remember and celebrate you until we join you.
Thank you, everyone. I'm going to close with a link to a favorite blog I did on Bob back in 2012: Watching Bald Eagles. The Raptor Resource Project wishes you and yours a very Happy Thanksgiving!


Tuesday, November 08, 2016

Where did all of those eagles come from?

Decorah North watchers know that we've seen an incredible number of eagles in around the nest, especially November 4th through November 7th. The tally looks something like this:
  • Friday evening, November 4th: What appear to be two sub-adult eagles are seen in the vicinity of the nest. A lot of vocalization can be heard off-screen, including chattering and pealing. Video: https://youtu.be/jLf2gYPVcyk
  • Saturday, November 5th: At about 8am, an intruding adult is in the nest with a sub-adult perched nearby. Mom and Dad North chase them off. At 6:03pm, a juvenile bald eagle perches on a branch near the nest but is chased away by Mom North. Chattering and pealing is heard offscreen several times throughout the day. Video: https://youtu.be/INVx8RInv98
  • Sunday, November 6th: A juvenile eagle is spotted on a lower right branch near the nest at 9:00am, but the true follies don't get started until 1:30pm, when an intruding adult female flies into the nest with two sub-adults (or an juvenile and a sub-adult) in hot pursuit. There may have been a third sub-adult in a tree near the nest, and there was definitely another sub-adult in a tree in the pasture. The immature and adult intruders are all driven out, but another adult (or the same one - we don't know) shows up later with food and is driven away. A lot of pealing and chatter can be heard off screen throughout the day. Video: https://youtu.be/zabzKoQjQnY
  • Monday, November 7th: A sub-adult eagle visits the North nest to play house at about 7:30am: https://youtu.be/Xaw5Yb_FUkY, followed by a pool party later in the day, when five immature eagles, one adult eagle, and two sandhill cranes were counted in a stretch of the stream that flows to the east of the North nest: https://youtu.be/hbhMkNcn7Y4
We are getting asked why there are so many intruding eagles here as compared to Decorah, and why so many eagles (and cranes!) right now. While the North Nest has tended to have more intruders, we haven't seen anything quite like this before. A few ideas:

On the question of location (North versus Decorah)
  • The North Nest is in a wilder area with more forests and natural terrain. While Decorah is very beautiful, it is a city on the eastern edge of an extensive agricultural area that stretches across the entire state. Decorah and areas west have much less habitat for wild animals. While only one of our tracked eagles have been seen at the North nest, many of them have visited the North area.
  • Consider an eagle migrating from Ontario to winter along the Mississippi. It will most likely fly along the west shore of Lake Superior before it peels off the tip where Minnesota and Wisconsin meet. At that point, it is about a 150-mile flight almost straight south to Lake Pepin - something eagles can do easily in a single day, especially if the winds are favorable. If they aren't, Wisconsin's lake country offers plenty of habitat for rest and relaxation. Once our eagle gets to Lake Pepin, it might chose to stay - many eagles do - or it might go further south to, say, Eagle Valley. The shorter straight-line path does not follow the river but cuts in-country through the vicinity of the North Nest, narrowly missing Decorah.
  • The North eagles are living just inside a north/south wind-funnel of sorts that cuts through the hills and channels wind - and birds - for miles. Topography influences migration in many birds, including bald and golden eagles. Looking at the terrain, it is no surprise at all to see eagles congregating here - even if the Norths don't exactly put out the welcome mat! 
In short, the North eagles are living in a region that has more habitat for bald eagles and other animals, is in a relatively straight line between critical upper and lower stretches of the river, and is in a long north/south valley that funnels wind and aids migration.

On the question of timing (why now)?
I asked bald eagle expert and board member Brett Mandernack if the eagles he is studying had left their summer grounds. He replied that they had, although given the warm weather, many were staging in Wisconsin and along the Mississippi river north of Eagle Valley. Presumably, these are eagles on their way south to somewhere else, but in no hurry given the weather. 

Unlike many birds, bald eagles migrate almost exclusively during the day. They rely heavily on thermal soaring to aid their flight, so a warm, sunny day with favorable winds can send eagles soaring by the thousands.


Let's look at the wind maps from the week of November 4, 2016. Wednesday through Friday would presumably have been excellent migration days: especially Thursday, which had favorable winds in addition to wonderful weather! But the winds started to change on Friday and were unfavorable from Saturday afternoon through at least late Monday afternoon. Why would eagles go anywhere if they had access to food, water, and high-quality habitat? The area around the North Nest provided a perfect staging spot for migrating eagles headed south. Perhaps large groups of eagles could have been found in many valleys in NE Iowa this weekend. We were fortunate to get to see these!

Chasing an intruding juvenile eagle from the North Nest

Chasing an intruding adult eagle from the North Nest

A visiting - and playful! - sub-adult eagle

Immature and adult eagles at the river east of the nest

Bathing - and interacting - at the river's edge

Sandhill cranes and an adult bald eagle
Chasing an intruding adult eagle from the North Nest

Did you know?
  • Juvenile eagles are fledglings in their first year. They are a darker brown than sub-adult eagles, with less mixed white and lighter brown plumage. Sub-adult eagles are 2-4 years old. They have very mixed plumage compared with juveniles and adults. Adults get their white heads and tails at around five years of age. Immature can refer to juvenile and sub-adult eagles. For more on aging eagles by plumage, visit this website: http://bit.ly/1aGakDV
  • Although bald eagles take advantage of solar power by migrating during the day, many birds migrate at night. It is believed that night migrations allow them to avoid heavy winds and storms, since nights are often calmer; keep away from predators, especially birds of prey that hunt and migrate during the day; and preserve water and energy, since cooler night-time temperatures will induce less heat-related panting.
  • Check out Brett Mandernack's .pdf of D1's migration paths. You can see a real preference for direct lines, especially on repeat journeys. She tended to cut down pretty directly through WI, unsurprisingly passing through the North Nest region, although she was never at the nest or its vicinity that we know. 

Thursday, November 03, 2016

Personalities

Filed under #musings. A recent study on animal personalities got me thinking. Are the differences we see from nest to nest a product of our imaginations, the surrounding area, or their personalities?

Between 2003 and 2015, we watched bald eagle families on four territories: Decorah and Decorah North in Iowa, Fort St. Vrain in Colorado, and Eagle Valley in Wisconsin. They were very similar in their broadest outlines, since all four territories:
  • Were inhabited year-round by a territorial pair of eagles.
  • Were close to bodies of water.
  • Had distinctive seasons that included cold snowy winters, short unpredictable springs, and hot summers.
  • Were near what appeared to be ample food supplies: the trout hatchery in Decorah; a river, watering hole, and prairie dog colony at Fort St. Vrain, a trout stream and farms at Decorah North, and the Mississippi river at Eagle Valley.
However, watchers of the Decorah and Decorah North nests observed some big differences between the two last year.

At Decorah
We have been collecting data on this territory since 2006, when Neil and Bob began filming American Bald Eagle. We don't know Dad's age, although he is older than Mom. Based on her barely-adult plumage when she began nesting here in 2007, she turned 13 in 2016. Both eagles are experienced parents.
  • Both parents spent a lot of time on nestorations: bringing in sticks, arranging sticks, and moving sticks. 
  • The 'pan-tree' was almost always full. It wasn't uncommon for the nest to contain four or five prey items - not surprising, since Dad was observed bringing in as many as five fish in one hour! 
  • Both parents fed young on a regular basis. While Mom tended to take over feeding, Dad fed when he had a chance. The eaglets were fed together and separately. Human watchers believed that Mom and Dad tried to make sure both eaglets got sufficient food. 
  • A parent - usually Mom but sometimes Dad - was always present in the nest until long after the eaglets could thermoregulate.
  • The eaglets showed less aggression towards one another.
  • Fish made up a larger part of the eagles' diet.
  • Egg-laying started on February 18.
At Decorah North
We have been collecting data on these two eagles since February of 2016. We do not know how old either eagle is (although both appear to be full adults), how long they have been together prior to last fall, or how long they have been parenting.
  • Less time was spent on all aspects of nestoration during the period we were able to watch both nests. Fewer sticks were brought in and the eagles spent less time moving and rearranging them.
  • The parents did not cache nearly as much food in the nest. 'Field-dressed' prey was more commonly brought in than entire chunks or whole bodies that needed defurring or descaling.
  • Young were not fed nearly as often and separate feedings were not as common. Human watchers believed that Mom and Dad did not try to allocate food evenly between the eaglets.
  • Parents were not always present in the nest. Human watchers believed that they were more attuned to the brooding needs of the two older eaglets versus the youngest one.
  • The eaglets showed a great deal of aggression towards one another. Sibling aggression was a factor in DN3's death.
  • The prey base was wider and did not include as much fish as the Decorah nest - although based on a journal by Sherri Elliott, fish still comprised around 66% of their diet. It included opossum, muskrat, raccoon, fawn sections, rabbit, mink, cow placenta, birds, waterfowl, a cat, and unknown pieces of meat.
  • Egg-laying started on March 11.
  • The North Nest had more nest intruders and slightly harsher weather.
At the time, we believed that the difference in parenting styles was driven primarily by food availability at each nest. Since the Norths brought less food into the nest, it made sense that less food might be available overall, and their relative absence could be explained by the need to spend more time hunting. Food was also clearly a big factor in eaglet aggression, which tended to determine who was fed first or at all.  Our conclusions were consistent with earlier studies of bald eagles conducted at Besnard Lake, in Alaska, and on Chesapeake Bay. You don't have to watch eagles very long to realize how important food is. But could eagle coping styles/personalities also be playing a role? 

Let's start with defining the term 'copying style'. Jaap Koolhaus (Koolhaas et al. 1999, 2010) describes a coping style as a correlated set of individual behavioral and physiological characteristics consistent over time and across situations. Researchers divide coping styles into proactive and reactive groups:
  • Proactive individuals respond to stressful situations with action. They build rigid routines, explore territories quickly, develop superficial maps, tend to be offensive towards conspecific rivals, are impulsive in decision-making, score high in frustration tests, take risks in the face of potential dangers, and are novelty seekers. Perhaps as a result of their routines, they are less responsive to short-term changes in their environment. 
  • Reactive individuals respond to stressful situations with immobility. They are less likely to build rigid routines, explore territories slowly, develop deeper maps, and tend to be less offensive towards conspecific rivals. Perhaps as a result of their flexibility, they are more responsive to short-term changes in their environment. 
So how might behavioral type affect local space use in bald eagles? Unsurprisingly, it is a complex question. As defined above, the North adults seem proactive (quick, active, aggressive, less responsive to environmental changes and external stimuli) and the Decorah adults seem reactive (slower, less active, possessing a deep understanding of the territory, very responsive to environmental changes and external stimuli). One of the things that watchers commented on was the absence of Mom and Dad North when compared to Mom and Dad Decorah. Several studies have found that proactive individuals show a wider ranging space use than their reactive counterparts. The North eagles spent less time in the nest and on the nesting tree last year. Was that driven only by food availability or did a deep-seated need to range also play a part? We also discussed the differences in parenting styles quite a bit. The Decorah eagles seemed to human watchers to be much more reactive to the needs and behaviors of their eaglets than did the Norths. Did personality have anything to do with it? 

A lot of the narrative around both eagle families seems to fit nicely into a proactive/reactive box. But what about prey piling and nestoration? Watchers identified prey piling as a big difference between the two families. The Decorah eagles piled prey high (and have ever since we began watching them), while the North eagles seldom cached prey in the nest (although left-over turkey feathers piled up, they didn't make a meal). Similarly, the Decorah eagles spent a lot of time working on their nest (Dad's sticky OCD, anyone?) when compared to the North eagles. These seem like rigid behaviors, not flexible responses to the environment, which puts them firmly in the proactive category. It could be argued that, unlike the Decorah eagles, the Norths didn't flexibly respond to changes in their environment (eaglets) with changes in their behavior (caching prey). However we categorize their behavior, both pairs of eagles appear to be using environmental information in different ways.

It hasn't been that long since it was taboo to think of animals as anything other than clinical study subjects. Changes in our way of thinking and advancements in research and study techniques have altered that. I am firmly convinced that personality plays a part in the unique behaviors seen at each nest (although food remains important) and I am looking forward to more research on the topic.

Note 1: Dana Bove of the Boulder County Audubon contacted us about bald eagle monitoring. He developed an Excel worksheet to monitor nests outside of the active reproductive period, i.e., when eagles may be in and around the nest, but aren't productively copulating, laying eggs, incubating, or caring for young. We were very interested in them given the differences in the Decorah and Decorah North nests. How big were those differences in behavior? We received permission to use his protocol and put it online here. Please feel welcome to start sharing your observations via the tool. This is a bit of an experiment for us, so feel welcome to share feedback as well!

Note 2: Some watchers believe that parental experience also played a role. Like many animals, eagles get better at basic parenting skills with experience. Could some of the differences in preparation and provisioning also be a matter of an experienced parent at the North Nest?

Note 3: Could nest invaders be another piece of the puzzle? Eagles enthusiastically steal prey from one another and hungry hawks will sometimes invade as well. Could the difference in prey piling and preparation be in part a response to potential competition and nest invasion? A lot to think about!



We see proactive and reactive behaviors in nesting peregrine falcons when we handle them for banding. Some falcons foot and bite the entire time, while others are very docile and don't put up a struggle at all. A few observations...note that these are anecdotal:
  • Highly aggressive females seem to replace highly aggressive females. I can think of at least three sites where female falcons were dangerously aggressive. We've never had anything but dangerously aggressive falcons at those sites. 
  • There is a general belief that highly aggressive falcons produce highly aggressive offspring, although to my knowledge it has never been formally studied.
  • Footy, bitey males tend to be older than female siblings based on plumage growth. 
A study on crows found that dominance-related parameters of age and sex did not coincide with proactivity. I wondered about this since older, bigger eaglets tend to be more dominant, and older nestling falcons are more likely to be aggressive when handled. In effect, a study on this would be looking at whether birth order influenced personality/coping strategies. We plan to start assessing docility in nestling falcons next year for comparison with their behavior should they survive to adults. We will also keep notes on dispersal - so keep those band numbers coming!

References