News from the Nest Box

August 11 – The weather is getting cooler and change is in the air. The one thing that doesn’t seem to change, however, is Hattie making window visits to staff and patients alike! The latest “Hattie” report was from Dr. Jad Sfeir, of Internal Medicine. He graciously shared his selfie encounter photo with the peregrine team, saying she kept posing for the photos, looking straight at the camera and didn’t leave until he was done. What a wonderful opportunity and experience! Thank you so much Dr. Sfeir for sharing such a wonderful photo with us. How many of you have had similar experiences?

With the cooler weather, it is also expected that many birds will soon begin their migration journey.  Although Hattie and Orton reside in Rochester, Minnesota year round, many other birds don’t, including the 2022 fledglings Comet, Rebel, and Nova. Confirmed sightings of this year’s fledglings haven’t occurred since the first week of August, but that is normal behavior for peregrines. Typically, the fledglings only stay with the adults in their home territory for 6-8 weeks, before they explore their surroundings and find other places to call their own. Sometimes, the distance may only be 50-75 miles, and sometimes it may be 500 miles or more. We will have to patiently wait to hear reports or receive a note, telling us of a sighting. This is one of the most important reasons we band the peregrines in the first place to find out where their “wandering ways” take them. It is also possible that the fledglings are still within the Rochester city limits, and haven’t begun their first migration as well.

We would love to hear about any peregrine sightings, especially if you can read the band information on their left leg. You can send your reports to us at peregrines@mayo.edu. Happy birding!

July 11 – Many of our falcon fans have recently emailed us, wanting to know if we had any news about the three fledglings or the falcon family since the last chick fledged on June 18th, 2022. Despite numerous days and nearly 40 hours spent over the past three weeks, we have very little information to share with everyone.

We DO know that both Hattie and Orton are doing well and are found during every visit. As can be expected, since the chicks have left the nest box, the peregrines have little need to spend much time at the box. Instead, they are using other areas of their territory, which includes the entire Rochester area. Lately, they appear to spend most of their time on buildings on Broadway Avenue, or the Gonda and Siebens building. The adults are busy teaching the young birds how to hunt and help out with a feeding if they are unsuccessful. 

Unfortunately, we haven’t been able to find all three remaining fledglings perched in a visible spot or perched long enough to get an ID on their banded leg. We have observed two fledglings in flight numerous times, but again never in a situation to be able to confirm their identity. These are the challenges of peregrine field work once the chicks have fledged. We do know that Rebel is still alive, since the one bird observed today was significantly smaller than the other fledgling.

We will continue to leave the camera on for the next few weeks, in the hopes of catching a glimpse of a visit by one of the falcons. We will continue to do weekly on-site monitoring and hope to have more information to share at our Facebook LIVE event on July 18th at 11 a.m. https://bit.ly/3bLDSIo

June 22 – On Monday, June 20, Facilities staff were finally able to safely access the peregrine nest box atop the Mayo Building and retrieve the remains from the chick which passed away on June 10. As we mentioned before, it wasn’t feasible to do so until the remaining nestlings had fledged from the box and were not in danger of being startled by staff approaching the box. 

Because of the delay in retrieval, it isn’t a surprise that after examining the remains, authorities cannot speculate as to the cause of death. This is unfortunate, but our obligation was also to the remaining nestlings in the box and is at the basis of all decisions being made in regard to the birds. We appreciate everyone who has written or sent messages about this loss, which you can imagine has also impacted the staff and the entire peregrine falcon team.

For now, we are going to maintain the camera view on the outside camera only, since there is very little activity occurring in the box itself. This will also allow us to view any of the falcons within the immediate area of the roof, and help our monitoring efforts on the remaining peregrines. This is a fast-paced time of learning for the fledglings, as they are learning important life lessons from Hattie and Orton on flight skills, hunting, and adapting to an urban landscape. As of today, two of our fledglings have been observed with the adult falcons. We will continue to try and confirm the identity of all peregrines, when possible.

June 20 – Today we had the good fortune to return Nova to her home on top of the Mayo Building. On Saturday morning, Nova was found and rescued from a bench outside the Stabile Building on the downtown Mayo Clinic campus. Mayo Facilities contacted Jackie Fallon to determine the course of action. It was decided that Nova should be transported to Foxloft Conservancy, a wildlife rehabilitator in southern Minnesota, for further evaluation. It was determined that Nova needed to be examined by a licensed veterinarian, so Jackie transported her to the Raptor Center at the University of Minnesota in St. Paul. Nova received a clean bill of health and was cleared for release back at her home territory.

Early Monday morning, Jackie coordinated Nova’s release with Mayo Facilities staff. Before we could return Nova to the rooftop, we retrieved the remains of Tom, the falcon that passed away on June 10. We decided that the best location to return Nova was the subroof below the nest box itself. This would provide a larger area for Nova to get her bearings when she left the transport carrier. This way, Nova would take her time before attempting flight again. She still has about about a half-inch of feather growth to occur, which will give her more control in flight.

The transport box was placed in a shaded area on the subroof and the door was opened. Meanwhile, Hattie promptly flew overhead, screeching, which was an encouraging sign indicating that the adults knew where Nova was. After a few minutes of assessing her surroundings, Nova slowly backed out of the crate, keeping a close eye on the human guardians nearby. She then took a low flight toward the center of the roof and flew out of view.

We will be submitting the remains of Tom, the falcon nestling, to try and determine cause of death. However, at this stage and delay in ability to retrieve the remains, we may never know the true cause of death. Stay tuned for more information, as it becomes available.

June 14 – As of June 14th, Comet, Rebel and Nova have all successfully fledged from the nest box atop the Mayo Building in Rochester. Nova, the youngest chick, took flight in the afternoon, but only made short trips from the safety of the box. In today’s photo, you can see that all three are doing well, and continuing to spend the night back in their nest box-a place that is familiar and safe. 

Due to her age at just 41 days old, Nova is definitely on the younger end of fledging age for a female peregrine. We say that, because her flight feathers in the wings and tail still have almost an inch to grow before being fully capable of sustained and controlled flight. When nestlings prematurely fledge in this physical state, they run a much higher risk of colliding with objects or ending up in dangerous situations. With the expected rain tomorrow, we hope that she will remain in the box a little bit longer, to gain every advantage of development that is possible.  

Because Rebel fledged first, is the oldest, and a male, falcon fans may not observe him in the nest box very often anymore.  His flight skills are improving on every successful flight and will begin to chase prey and the adults more often. This is the final stage of development and gaining independence as a peregrine. As we get reports of his whereabouts, we will be sure to share them with you. They are certainly living up to their name “The Wanderer” at this age.
 

Although Nova has officially “fledged”, it is still unsafe for the team to approach the nest box to retrieve the remains of falcon “Tom”.  As soon as it is safe to do so, we will collect him and bring the remains to a veterinarian for a necropsy, although it will be difficult to identify for certain a cause of death. Thank you to all of our falcon fans for your emails of support and understanding during this difficult time.

June 13 – This photo, time-stamped 5:38 a.m. CDT,  shows Comet atop the nest box, just after she fledged.  You can also see Orton on the deck, delivering breakfast. Nova is the youngest of the group and will hopefully stay in the nest box a few more days, until her feathers are more fully developed. Female peregrines are slower to develop than their male siblings, and have a more difficult time at fledge when they try to fly before they are truly ready to do so.

Note:  We are sad to report that one of the four peregrine falcon chicks passed away. Please know that the deceased bird will not be retrieved at this time because the nestlings are so close to fledging. If anyone would approach the nest box now, it’s likely that the nestlings would jump from the nest box and suffer injury or death because they cannot yet fly. The welfare of the three remaining chicks, as well as Hattie and Orton, remains our top priority and is at the heart of all decisions being made.

June 12 – We are happy to report that “Rebel” has successfully survived his first day of independence and has safely returned to roost in his natal nest box with his siblings. As you can imagine, there are many threats and unknowns that a newly fledged peregrine must learn about, if they are to survive in their new world away from the eyrie (nest). Typically, a newly fledged falcon will return to the immediate area around the nest for the first few weeks, where they are most comfortable and familiar, before venturing farther and farther away. Stay safe out there Rebel!

June 12 – We have fledge!  At 8:54 a.m. CDT this morning, Rebel (one of the male chicks) spread his wings and took his first flight to the top of the nest box atop the Mayo Building in Rochester, MN. (This image is a screenshot, captured by our outside deck camera and Media Support Services staff). So far, Rebel has made several short flights around the area, and has safely returned to the nest box throughout the morning. If all goes well, he will return to roost in or near the box tonight with his siblings, on his first night of independence.

On that note, you might have noticed that the camera feed is up and running again. The peregrine falcon team has opted to turn the live feedback on to allow you to watch the fledglings up close.  While everyone has shared in the sorrow over falcon Tom’s unexpected passing, there is also a realization that this is part of nature. We have received numerous emails and comments via our Employees of Mayo Facebook page to watch the remaining falcons as they fledge and develop into independent peregrines.

Another common question we are receiving is: When will the two females take their first flight? Of course, the birds have their own schedule on these things, but we would expect Comet to fledge early this week, and Nova a day or two later.  That said, sometimes the birds inadvertently end up being jostled out of the way on the deck and may prematurely fledge before they are capable of sustained flight. Fortunately, there is a sub roof right below the box, which should provide them with a safer landing than the street below. Stay tuned!

Note:  We are sad to report that one of the four peregrine falcon chicks passed away. Please know that the deceased bird will not be retrieved at this time because the nestlings are so close to fledging. If anyone would approach the nest box now, it’s likely that the nestlings would jump from the nest box and suffer injury or death because they cannot yet fly. The welfare of the three remaining chicks, as well as Hattie and Orton, remains our top priority and is at the heart of all decisions being made.

June 10 – We are aware of and are monitoring concerning developments in the nest box. It appears one of the young birds in the back of the box is not moving. Jackie Fallon, our expert from the Midwest Peregrine Society, is investigating and in contact with the Minnesota Department of Natural Resources. Right now, it’s not possible to get near the nest box as it would jeopardize the safety of the other young birds who are preparing for their first flight. We have received many messages from concerned followers and apologize that we are unable to respond to each one at this time. We’ll post updates as they become available.

In the photo above, taken around 5 p.m. today, Orton delivers prey and feeds three youngsters. 

Update (6:30 p.m. CDT) – We are sad to report that one of the four peregrine falcon chicks passed away this afternoon. By reading the bands of the three remaining chicks, Jackie Fallon has confirmed that the deceased bird is Tom (b/blu 95/U). Jackie and team cannot confirm the cause of death and cannot speculate. Please know that the deceased bird will not be retrieved at this time because the nestlings are so close to fledging. If anyone would approach the nest box now, it’s likely that the nestlings would jump from the nest box and suffer injury or death because they cannot yet fly. The welfare of the three remaining chicks, as well as Hattie and Orton, remains our top priority and is at the heart of all decisions being made. For now, the live falcon cameras have been turned off.

Thanks to all who have been faithfully following our falcons this season.

June 6 – We are in the final week of the chick’s life in the nest box. By this time next week, it is possible that the oldest chick will have taken the leap of a lifetime and move into its next stage in life: Fledging! 

Peregrine falcons typically fledge at about 40-42 days of age, with males fledging before the females do, because they are quicker to develop. Some female peregrines won’t fledge until they are closer to 44-46 days old. For the 2022 Mayo brood of chicks, this means that we would expect the order of fledging to go as follows: Tom bblu 95/U; Rebel bblu 94/U; Comet bblu R/30 and Nova bblu R/31.  The term “bblu” means “black over blue” band and the letter and number combination is the auxiliary band identifier on each chick’s left leg. This color combination signifies that the chick hatched in the eastern U.S., according to the color assignments by the U.S. Fish and Wildlife Service and the Bird Banding Lab. This is an extra band which we place on the chick that you can easily read on camera. This helps us monitor the chicks without approaching them too closely.

Learn more about fledgling behavior and the challenges that newly fledged chicks face as they take their first flight through the special “Meet the Falcon” program available here:  https://www.facebook.com/events/589469192407279

June 2 – The chicks are now at about full adult size and body weight, at 28 to 30 days old. The majority of their development at this point is advanced behavior and growing outer body and flight feathers. The oldest male and female chicks are nearly 50% or more brown and really beginning to look like peregrine falcons. The youngest male is considerably behind in his outer covert feather development compared to his oldest siblings, but I can assure you that this is normal and he is just fine.

The chicks are also spending A LOT of time preening during the day, and even nighttime. Those feathers are somewhat “itchy” and they need great care to stay healthy. The falcons gather a special oil from a gland at the base of their tail to apply to the feathers, which helps to keep them clean, healthy and waterproof.

You may also see the chicks start to fight over food that is brought to them by the adults, and even stealing the entire prey item, and try and keep it for themselves.  This is when being an older female might have some advantages over a younger male sibling, even when that age difference is only two days. Again, the adults are spending almost no time in the box now, because of the age of the chicks and aggression towards the food they deliver to the box.  Both Hattie and Orton continue to spend quite a bit of time hunting, in order to feed the four chicks and themselves. As we’ve mentioned before, pigeons are an important prey item for the falcons, in addition to other small to medium sized birds and even an occasional bat!

May 30 – Happy Memorial Day! The nestlings are now 25-27 days of age and progressing nicely to the next stage of their development: getting ready for their first flight! As you can see, Comet (the oldest female) has made the first jump onto the outside nest box deck. This is a natural progression in a peregrine’s development, where they start exploring their surroundings, stretching and jumping, and becoming an independent falcon.

You may also notice how many more brown feathers are growing in on their outer body, and the increased length of their flight feathers on their wings and tail. At this stage (25-35 days of age) they seem to physically change right before your eyes! They are becoming bolder with each other and towards the adults when food is present, sometimes quite aggressively. They will start to tear apart food on their own and won’t need to be fed by their parents anymore either. This is all part of growing up on their journey to independence and venturing out into the big world beyond their natal territory.

May 25 – Well, the big day finally arrived! The staff from Mayo Clinic’s Peregrine Falcon team and Midwest Peregrine Society banded the four nestlings earlier today, as part of a live feed on the Clinic’s social media page. The team carefully planned out the day’s event on who was doing what, and how best to make it all happen smoothly and efficiently.

The team gathered at 11 am to meet one another, our invited guests from the media, and the Child Life team. Jackie Fallon, peregrine state coordinator for the Midwest Peregrine Society, explained the process to those who had never experienced the retrieval and banding event, so we could then focus on things once we accessed the roof. At noon, the entire team and guests proceeded to the rooftop of the Mayo Building to retrieve the chicks from the nest box. While Jackie, Tom Behrens from Facilities Management and Peter Smerud from Wolf Ridge ELC transferred the chicks from the nest box to the transport box, other staff held umbrellas over the team to protect guests and those at the box from the defensive flights of the parents. As you can imagine, the adults are protective against any threats to the chicks, including humans. Thankfully, things went according to plan, and within minutes we had retrieved the chicks and were off the roof.

The next stage of the event was to gather in Judd Auditorium on the Mayo campus, where the actual banding would take place. While Peter removed each nestling from the transport box and weighed it on the scale, Jackie determined whether the chick was a male or female in order to apply the appropriate sized band. Jackie recited the band number and information to Trish Amundson from the Heritage Days Committee, who then recorded all the vital information in the record book. Jackie then applied the bands on each chick, performed a quick exam to look for any signs of illness and then the banded chick received its name. 

This year’s brood included two male and two female nestlings. The names for the chicks were submitted from Mayo employees across the country, as well as school children and other interested falcon fans.  We received over 1700 names from nearly 500 people, which was amazing!  The committee made a final selection of twelve names to choose from via a drawing once we knew what sex each chick was. The Child Life team members were given the honor of drawing the final name choices from the bins, and they are as follows: the female names were Comet and Nova and the male names were Rebel and Tom. The name Tom specifically was chosen to honor Tom Behrens for his 30 years of service and support of the peregrine falcon program at Mayo.

We hope everyone enjoyed watching the banding and naming event this year. This is always an exciting day for everyone on the team, as well as our thousands of falcon fans all over the country. The chicks will be changing almost daily now with their feathering, from white fluffy balls of down to sleek brown and cream fledglings, and taking their first flight in about three weeks’ time.  

If you missed the live event, you can view it online in two parts:  

Part 1  https://bit.ly/38s2KDM  

Part 2  https://bit.ly/3Lj8Q6G   

May 20 – The eyasses (nestlings) are now 15-17 days old and are seeming to grow larger right before our eyes!  At day 14, they start growing their flight feathers on their wings and tail, which requires even more food than ever. Both adults are now actively hunting for the family, as shown in this photo. Hattie (right) had just brought in a pigeon, while Orton (left) brought in a much smaller songbird. You might even notice that the eyasses are constantly vocalizing to their parents, to bring them more food.

You may also notice that the chicks are spending more time flapping their wings and awkwardly stumbling about the box. They are becoming more curious about their surroundings as well, and even starting to pick up pieces of food left in the box by the adults. It always amazes me how quickly they change and develop motor skills in such a short period of time.

We want to thank everyone who submitted names for this year’s brood of chicks. We had over 400 people submit over 1600 names, which is AMAZING! The names have come from employees as well as community members, both near and far.  The creativity in names submitted ranged from things that reflected Mayo Clinic’s history and staff, the biology about peregrine falcons, to important historical events and people in 1987, the year that Mayo Clinic joined the restoration efforts to save peregrines in the Upper Midwest. The submission list is now closed, and the falcon committee is now starting to look through all of the names to come up with a list for Wednesday’s banding and naming event. I can tell you it will be a difficult decision to try and select 12-15 names for the drawing of names at the banding and naming event.

A reminder to watch us LIVE on Wednesday, May 25th at noon – 12:50 p.m. Central Time via Facebook Live. Part 1 (12-12:10 p.m.)  https://bit.ly/38s2KDM  and Part 2 (12:20-12:50 p.m.) https://bit.ly/3Lj8Q6G.  Part 1 will be video feed of the field team and Mayo staff retrieving the eyasses from the roof of the Mayo Building, while Part 2 will be the actual banding and naming event. The videos will be available after the banding and naming, for those who cannot watch the process live. We hope many of you can join us in celebrating 35 years of peregrines at Mayo Clinic.

May 15 – The falcon chicks are now 12, 11, and 10 days old and beginning to explore the nest box independently of each other. This also happens because they are developing more feathering and no longer need to stay huddled together for warmth. You may even see them spread out and appear to be sick or unresponsive. I assure you that this body positioning is completely normal and how the nestlings get rid of excess heat with the warmer temperatures. This is also how they rest during the day. Today’s photo is a perfect example of normal chick and adult behavior, in dealing with a warm, sunny morning.

You may also notice in the photo that the adults may pant (open their mouth to breath) and hold their wings open and away from the body. This is how they will keep their body cool, when they aren’t taking a bath in cool water.  Those same feathers that insulate them against -20 degrees F weather are also very insulating during warm spring and summer days. In this photo, Hattie is also sheltering the single chick in the middle from the sun. As we’ve mentioned before, our nest boxes purposely face east to only get morning sun instead of excessive afternoon heat.

Lastly, we’ve received numerous emails this week about not seeing the chicks and being concerned about them. Please don’t be alarmed if you only view one chick in the box, or if you don’t see any chicks in the overhead camera view. This camera angle doesn’t cover a small area at the very back of the box, and the nestlings are often lying down in that area and are out of view. If something should happen to the chicks, we will be sure to alert you of significant changes via the Employees of Mayo Facebook page or on this website. 

A reminder to send your naming suggestions to HeritageDays@mayo.edu by May 20th at 5 pm.  We have already received some wonderful choices for this year’s “Class of 2022”, celebrating 35 years of peregrines at Mayo. Thank you all!

May 10 –  The chicks are now 5-7 days old, and all appear to be doing very well. Hattie and Orton are being kept busy by catching enough food and keeping the chicks warm. At day 7, the two chicks are nearly three times larger than they were when they hatched!

You may notice that the adults are starting to leave the nestlings alone a little bit more and more each day. No need to worry, one of the adults is right nearby, perched just outside the nest box at all times, while the other one is out trying to catch more food. Also, the weather is finally warmer, so you may see the adults shading them from the sun as well. Lastly, the chicks are also growing in more feathers, so they can start keeping themselves warm enough, without help from the parents. Life is busy, and exhausting for the nestlings, so unless they are eating, they are sleeping. Soon enough, they will start standing up more and start preening in those new outer feathers that will start to grow in.  Until next time…

May 5 – Just when we were receiving numerous email inquiries about the possibility of egg number 4 hatching or not, the little chick arrived right when it was supposed to do so. At about 3:15 pm today, Orton brought in some fresh dinner and Hattie immediately started feeding the four chicks. You can even see that one chick in the center grouping of three, is still fairly wet and not dried off from hatching. It can take up to an hour or so to dry off and they won’t generally eat much the first 24 hours, if at all.

Now that all four eggs have hatched, you will see more and more food being delivered into the nest box by Orton. Also, Hattie will start leaving the box more in the upcoming week and allow Orton the opportunity to feed the chicks as well while she will eat her meal just outside the nestbox. Also, don’t be alarmed if you don’t see each chick receive exactly the same amount of food as their sibling. The chicks don’t need to eat more than a few mouthfuls right now, and they will be offered food every few hours-day and night.

May 5 – Breakfast in Bed!  Hattie and Orton have been busy feeding and caring for the three new chicks (eyasses). Most often, Hattie is providing care for them, but every once in awhile she takes a short break and allows Orton some time with them. When Orton isn’t taking his turn with the chicks, he is busy trying to catch enough food for himself, Hattie and the new nestlings. Considering the chicks will double in size within 5 days, you can imagine how much food they need to eat. Pigeons are the primary food item brought into the box, but you may also see smaller birds as well. Peregrines have been known to prey upon over 100 different kinds of birds in Minnesota, but most often the prey range in size of 50g-500g in size.  Also, bats are occasionally taken in certain locations in the state, but never confirmed at Mayo Clinic.

May 3 – The wait is finally over and we had our first chick hatch this morning at 8:31 a.m.! It was noticed that a small pip in the eggshell happened yesterday, and over the next 24 hours, the chick used its egg tooth to slowly chisel its way out of the egg. You could even hear the chick peeping before it hatched, thanks to the wonderful audio in our nesr box! The remaining eggs should all hatch within the next day or so if they were fertile and healthy.

You may notice that Orton is making numerous visits to the box, hoping to entice Hattie off the eggs and chick. However, she is reluctant to leave them right now, so it is difficult to get a glimpse of the chick(s) nestled underneath her. Be patient and you might get lucky in catching a quick peek. As the chicks get older, and once all the eggs hatch, it will get easier to see them when the adults shift in the box or exchange duties.

At this time, we would like to formally open up the naming submissions for the 2022 brood, so feel free to submit your name suggestions to heritagedays@mayo.edu 

Suggestions will be accepted until  5:00 p.m. CDT on May 20th. Names of the chicks be announced during the banding event on Wednesday, May 25th at noon. Happy 35th Anniversary, Mayo Clinic Peregrine Falcon Program! 

April 24 – We are in the final days before the eggs should hatch! I know it seems like forever sometimes, but it has only been 27 days since the third egg was laid, and when “true” incubation began. Hattie and Orton have been doing a fantastic job of keeping the eggs at a constant temperature during this abnormally cold spring, and it can be difficult to catch a glance at the four eggs. We were lucky to catch this view of the eggs during such an exchange.

During hatch, the chick will use the egg tooth on top of its beak, to slowly chisel its way out of the egg.  This is called pipping, and can be exhausting for the chick. Pipping can take up to 72 hours or so, and during this time the adult may be acting very agitated and even appear to sit upright over the eggs. You may even hear them vocalize to the chicks while they are hatching! You then know the time is getting close.  We are estimating that hatch will happen around May 2nd to 4th, so start watching carefully for the first little hole or crack to appear around May 1st. Of course, we are all hoping for a full brood of four chicks to hatch, to help celebrate our 35th Anniversary.

April 10 – This afternoon, it was noticed that one of the eggs happened to get separated from the other three in the scrape. We are uncertain on how this happened, but after about an hour, Hattie noticed the lone egg while she was shifting position and gently pulled it back with the others. This should not make a significant difference in hatch, due to the warmer temperatures on Sunday, but time will tell when incubation is complete. We are on day 14 of incubation with the four eggs in the nest box on top of the Mayo Building and eagerly expecting hatch to happen the first week in May. We will have more updates during our monthly Facebook Live appearances on April 18th at 11 am CST. Bring your questions!

March 31 – The fourth egg arrived sometime overnight or early this morning. This photo, taken at about 9:50 a.m., shows a food exchange between Orton and Hattie before trading off incubation duties. Now it’s very interesting to watch the adults as they trade off to incubate the eggs. Hattie’s body is quite large so she has an easier time keeping all the eggs covered, while Orton has to do more shifting and maneuvering of his body.  

March 28 – The peregrine pair, Hattie and Orton, continue right on schedule with their egg laying sequence for the 2022 nesting season. The third egg arrived this afternoon, and while Hattie took a short break from incubating, we were finally able to get a screen capture of the three eggs in the nest box atop the Mayo Building. If history repeats itself, there should be one more egg laid in the gravel, although it is always possible to have up to five eggs. If there will be a fourth egg laid, it should arrive by March 31st, possibly a little earlier.  

Now that we have three eggs in the clutch, true incubation will occur by the pair of falcons. This means that the adults will rarely leave the eggs uncovered for more than a minute or so, unless the temperatures get in the 80’s or so. The adults keep the eggs at about 99.5 to 100 degrees Fahrenheit and will use their beaks to turn the eggs several times during the day. The female peregrine does most of the incubation of the eggs, while the male will relieve her of the duties during the day while she eats, stretches, or takes a short break. The female is rarely off the eggs for more than an hour at a time and does all of the incubation during the night hours. This is especially important when it is so cold out, like we are experiencing in Minnesota over the next couple of weeks.  

Our 2022 nesting season is off to a great start!  What a great way to celebrate 35 years of peregrine falcons at Mayo Clinic.

March 26 – Many of you might have noticed that egg #2 arrived sometime overnight, right on schedule. Today’s photo shows the male falcon, Orton, standing guard over the eggs. With the expected cooler temperatures over the next few days, you may see the adults covering them quite a bit. Just a reminder that they are just keeping the eggs from freezing, and not truly incubating them. Egg number three should arrive by Monday evening or by Tuesday morning.  

March 23 – The long awaited day arrived today, specifically at 10:37 am CDT…the first peregrine egg for Hattie and Orton’s 2022 nesting season! Hattie has been spending more and more time in the nest box the past few days, spending time perfecting the scrape where the eggs would be laid and just standing guard. This morning we noted that she was spending more time bending over, shuffling in the gravel, standing up, and then shuffling in the gravel again. Behaviors like this are strong indicators that a bird is getting ready to lay an egg. So, what’s next?  Here are some answers to common questions about egg laying and incubation.

Why do the peregrines leave their eggs uncovered during the first days? Peregrines don’t start true incubation until they lay the second to last egg of the clutch. This way, all of the eggs will hatch at about the same time. The adults may cover the eggs during really cold temperatures, but are not truly incubating them. This happens most often at night, especially in northern states where the air temperature is below freezing.

How many eggs will Hattie lay?  Typically, peregrine falcons lay between three and four eggs in a clutch. They can lay anywhere from one to five eggs in a single clutch. They will normally lay an egg every 24-48 hours apart, although sometimes it may take up to 72 hours between eggs. The eggs are a little smaller than the size of a chicken egg, and are speckled brown in color. 

How long is incubation in peregrine falcons?  Incubation for peregrine falcons is between 33 and 35 days from when that second to last egg is laid. Most often, all of the eggs will hatch within one to two days of each other, although we have seen it take almost four days in rare cases. Sometimes the incubation can last an extra day or two in cooler weather. 

Who incubates the eggs? Both adult falcons incubate the eggs, although the female peregrine spends the most time incubating, especially overnight. The male peregrine will take his turn incubating while the female is taking a rest and eating or stretching her wings. During this time, the male peregrine does all of the hunting, to feed himself and the female peregrine.

March 14 – Good evening, everyone!  We just wanted to give you a quick update on Hattie and Orton. The past week you might have noticed that Hattie is spending more time in the nest box than in previous weeks. As we get closer to egg laying, her hormone levels are increasing, and she is taking more of an interest in the nest box and defending the territory. So far this season, she has successfully defended the area from two other intruding females, which can be quite an intense and vocal display. Looking back at the past five years of data we have on the pair, we could expect to have our first egg laid by the end of March.

Thanks to AZ staff member Elias Chavez for sharing today’s image with us.

March 6 – A food prey exchange between two peregrine falcons is an important part of the falcon’s courtship behavior. Most often, it is the male peregrine bringing in a variety of food items to the female, showing off his expert hunting skills. This prey exchange can occur in the air or near the nest ledge, which is what is happening in today’s photo. Here, you can see Orton on the right side of the box with the partial pigeon and Hattie is bowing towards him on the left. Often the two birds will bow toward each other and be quite vocal during these exchanges. All of these behaviors and vocalizations help solidify the pair bond before the first egg is laid. 

This is also a great photo showing the size differences between a male and female peregrine. In the pair of falcons at Mayo Clinic, Hattie is nearly twice the size of Orton. In raptors, this size difference allows females to capture larger prey, while the males most often hunt smaller items under a pound in size. Here, this adult pigeon is over half the size of Orton! The powerful stoop flight is a wonderful adaptation for falcons, which helps them to capture prey such as ducks, grouse, and even birds as large as sandhill cranes!

February 27
In this photo you can see the adult female, Hattie, exploring the nest box. This is an important behavior for a nesting pair of peregrine falcons. Although the male falcon is often the one to attract a mate to the territory, it is the female falcon who chooses the specific nest site within the territory. As the female gets closer to egg laying, both the male and female will spend quite a bit of time in the eyrie (nest ledge or box) and make a scrape. You can see that Hattie and Orton have already been busy making this scrape, or depression in the gravel, which is where the future eggs will be laid.

Check out the new camera angle for a second view. The new camera system will toggle back and forth between the two camera views about every 20 seconds.

February 22, 2022 – Welcome back to the peregrine falcon nest box at Mayo Clinic and help us celebrate our 35^th year of peregrine recovery! 

Our new camera system gives you two different views into the box, along with audio of the falcons and their environment. One view is from the back of the nest box, looking outward towards the Plummer Building and the other view is from outside the nest box, looking inside.

It is still a little early to say with certainty which peregrine falcon pair will gain possession of the Mayo Clinic Nest Box in Rochester, MN., but so far Hattie and Orton, the resident pair here since 2016, have been successful in chasing away intruders such as Cooper’s Hawks, Red-tailed Hawks and other peregrines. In past years, we have observed as many as FIVE different female peregrines trying to claim the territory. This is one of the consequences of having such a robust and healthy peregrine population in Minnesota. 

Because it is still very early in the nesting season, the peregrines aren’t spending much time at the nest box itself but are somewhere nearby.  As we get closer to egg laying, both adults will be getting ready for the arrival of eggs by making a scrape in the gravel.  This scrape is a depression or bowl, which helps keep the eggs together and in a secure spot for incubation.  If Hattie and Orton continue to retain possession of the territory, we could have the first egg laid as early as mid-March.  Orton was spotted on camera over the weekend, making such a scrape in the box and vocalizing to Hattie.  This is very encouraging behavior, and we are hopeful for another successful nesting season on campus. For now, stay tuned and we will continue to share observations with everyone, as they happen.