2024 DATA RESULTS!

                                     2024 OSPREY RESEARCH AND PRODUCTION SUMMARY

By Vanessa Greene

The 2023-24 winter was very dry with little snow so our first Ospreys in the spring of 2024 were observed on 3/31, followed by many others in the first two weeks of April. In my 31st year of monitoring Osprey nests in the eight county Twin Cities metro area, the known population was somewhat stagnant. The number of occupied nests monitored was almost the same as last year, with a slightly lower failure rate, and an increased mortality rate over last year. The summer started out with heavy early rains and the second half of the breeding season was hot and dry. The early Ospreys laid the first eggs by April 15!

There were 183 nests which were occupied* by a pair of adult ospreys. (182 in 2023). There may be more nests we do not know about and we hope the public will continue to report new nests to us. We discovered 9 new nests, but also had previously occupied nests that were empty this year. Eggs were laid in 169 active* nests (174 in 2023). There were 134 nests that had at least one chick that was confirmed to have fledged successfully or survived to fledging age (129 in 2023). We documented 49 nests which failed (53 in 2023, 35 in 2022). We separate failed nests into two distinct subcategories; there were 12 nests where a pair was present but no eggs were laid (9 last year) and 4 additional nests where we are not sure if eggs were laid or not.

There were 34 nests where eggs were laid but they failed to successfully fledge a single chick or the cause of failure was unknown (44 last year). (Not laying eggs is considered to be a kind of nest failure by other scientists.) Out of those 34 failed nests where eggs were laid, there were 20 nests where hatching did occur but all chicks died. There were 13 nests where no signs of hatching were ever observed. The 2023 failure rate dropped to 27%. This represents a slight decrease over last year! (in 2023 the failure rate was 29%, In 2022 the failure rate was 21%, 2021 the failure rate was 18%, 2020 it was 27%, in 2019 it was 39%, in 2018 it was 29%, in 2017 it was 28%, and in 2016 it was 25%.)

There were 257 chicks that were known to have fledged successfully or survived to fledging age! (253 in 2023, 264 in 2022, 295 in 2021). Most successful nests had two chicks this year, with 64 nests with two chicks, 30 nests with three chicks, and 39 nests that produced a single chick.

The known mortalities of chicks this year were higher than last year with 57 chicks which were known to have died or disappeared before fledging, (47 in 2023, 23 in 2022, 26 in 2021). In addition, there were 9 nests where signs of hatching were observed, with adults feeding chicks, but they all died before we could get an accurate count. The causes for the increasingly high mortality rate among chicks are uncertain, but may be related to climate change. Many males seemed to be missing from nests more than usual, perhaps due to difficulties finding fish, requiring them to travel further, and be gone longer when hunting. Many females were observed leaving chicks alone to help provide food. We had at least 8 single parent nests. Many lakes had high algae levels which made fishing difficult. These circumstances may have resulted in brood reduction, starving chicks and increased opportunities for predation. There were 7 known adult mortalities and 3 banded males that disappeared mid-season, (but did not show up at The Raptor Center.)

There were only 45 adult Ospreys identified by their bands, as the number of banded birds continues to drop. There were four additional adults with silver bands that were unable to be read. We were sad to document that there were 6 color banded birds that did not return this year. Only one of the returning banded ospreys was from another state (Iowa).

There were 6 nests that were removed from cell towers or lights over the winter. We located 9 new nesting territories with a pair present. Of these new nests, 5 of them successfully fledged chicks, with outcome unknown on 1 nest. It is interesting to note that of the 183 occupied territories this year, 84 were on osprey nesting platforms, 44 were on cell or radio towers, 29 were on ballfield lights, 21 were on a power pole or transmission tower, 4 were on other manmade structures and 1 nest was built in a tree

The oldest male this year, was 21 years of age, with one that was 19, one that was 18 years of age. ALL of these older males bred successfully! Our oldest female was 18 years old, with three that were 17 years of age and all bred successfully.

The overall productivity of occupied nests which were successful this year rose slightly to 74%! (71% in 2023, 79% in 2022, 82% in 2021, 73% in 2020, 62% in 2019, 71% in 2018, 72% in 2017, 76% in 2016, 68% in 2015).

The mean number of young fledged per successful nest dropped slightly to 1.92% (1.96% in 2023, 2.00% in 2022, 2.11% in 2021, 2.04% in 2020, 2.09% in 2019, 2.13 in 2018, 2.25 in 2017, 2.24 in 2016).

The mean number of young fledged per active nest rose to 1.52% (1.45% in 2023, 1.65% in 2022, 1.78% in 2021, 1.65% in 2020,1.39% in 2019,1.64 in 2018, 1.75 in 2017,1.84 in 2016).

The mean number of young fledged per occupied nest rose slightly to 1.40% (1.39% in 2023, 1.58% in 2022,1.74% in 2021, 1.49% in 2020,1.28% in 2019, 1.51 in 2018, 1.62 in 2017, 1.70 in 2016).

A small group of nests had the chicks banded with silver bands only. Three chicks received silver bands while in rehab, prior to release. In spite of many days of searching, and reading 14 silver bands, we were unable to locate any of these rehabbed chicks to confirm survival post release. We will continue to watch for them in future years.

It is interesting to note that we have recorded 3,773 chicks that fledged from monitored nests since the inception of this project.

-----------------------------------------------------------------

*Successful nests are those that were known to have fledged at least one chick successfully, active nests are those where eggs are laid and occupied nests are those where pairs are present at a nest site for a period of time, regardless of the time of year or whether or not they lay.

ACKNOWLEDGEMENTS 2024

 Let me start with the acknowledgements for 2024…..and the data results will be posted in a few days!

ACKNOWLEDGEMENTS 2024

There are so many people who have been instrumental in helping Twin Cities Metro Osprey Watch continue this Osprey research. This year, 2024, marked my 31st year of monitoring all known nests in the eight-county metro area surrounding the Twin Cities of Minneapolis and St Paul, and I could not do this without a great deal of help. The careful, monitoring of these nests and the consistent collection and analysis of data over so many years may prove to be a significant contribution to understanding the world we live in, the health of our environment as well as overall productivity and behavior of this population of Ospreys.

Special thanks to Carol Christians, Alice Stoddard, Dani Porter Lucero, Meg Smith, Debbie De Frank Jordan, Ann Merritt, Larry Luebben, Jack Kimmerle, Pat Norton, Jean and Rob DeZeeuw, Donna Daubendiek, Rick Endo, Mary Mullet, Cindy Angerhofer, Stephanie Burley, Allison McGinnis, Brenda Goeltl, Ken Fischer, Gail Isaak, Marjorie Heap, Vicky Douglas, Tammy Holmer, Ann Altman, Lisa Gilliland, James Kelley and Will Hathaway for sharing their observations, their commitment to this effort, their photos, information, and their love for these birds. I am deeply, profoundly grateful to those who kept their commitments and kept an eye on the nests throughout the season. With the continuing growth of the project, I simply can’t do it all alone.

Thanks to all the private property owners who are such important and wonderful hosts to our Ospreys, and who have provided me access to these nests for monitoring.

A very deep, heartfelt thanks to all who contributed financially to this project in 2024: Ruth Rechtzigel, Debbie Jordan, Rick Endo, Carol Craig, Cindy Angerhofer, Betsy Kerr, Ann Lund, Allison McGinnis, John Muelken, and Jonna Bollum!

A huge thanks to The Raptor Resource Project for their generous ongoing support.

I am deeply grateful for all the help I have received in so many different forms, and for showing your faith in my ongoing efforts to continue this research study.

Vanessa Greene

February 2025

Osprey.mn@gmail.com

“Twin Cities Metro Osprey Watch” on Facebook

Ospreywatch.blogspot.com

February 2025

 Hello Osprey people…..I know you’re thoughts are beginning to turn towards our feathered friends and people are looking on this page for last years results. I am still working on the annual report but was slowed down a great deal by getting very sick in late December / early January and ending up in the hospital. I am recovering slowly and working on the huge pile of data we collected last year. Every year wrangling all the data into a cohesive report gets harder!  It’s a lot of counting, recounting, cross checking, digging thru all my notes as well as all the reports from the monitors, making decisions about how to categorize outcomes on every nest….sometimes we just don’t have all the info. We can’t be at every nest, every day!  It looks like we monitored 183 nests last year! I hope to have it all finished by the end of February. Thanks for your patience! Stay tuned….

Light heart….

 Happy Solstice, Happy Holidays to all…..on this darkest day in what is for many, a dark year. I recently read a wish for light heartedness….and it struck me deeply. It’s hard to feel light hearted sometimes, but it’s what I wish for you all. Perhaps it’s just a fleeting moment of quiet as you walk outside during the blue hour of the evening, looking at Christmas lights….or as you watch a sunrise in the deep mid winter. I send gratitude to all the people in the past 31 years who I have shared my love for the ospreys with…even those who are no longer in my life. I honor the love we once shared.  May you all know a moment or two of light heartedness as this challenging year comes to an end. We are all more connected than we realize. It’s our job to try to find the light, in our own hearts, in each other and in the world. Look for the light. 

September 27

 Today I went back for another visit with the ospreys in the last post. I quickly spotted the Dad across the lake ( first photo) with a big fish. But I heard no food begging from the juvenile. I watched and kept hiking around the lake to get a little closer….and closer….and I scanned all the usual perches but did not see or hear the youngster. Very quiet, the lake was like glass….i heard squirrels rustling thru the dry leaves. Dad was eating a few bites, and then stopping, listening, scanning the area in all directions….then a few more bites and he would stop again and look for his offspring. He searched the sky above too. Finally he flew off, back towards the nest. So I followed him and found him perched on some ballfield lights…..still looking in all directions. He had half the fish in his talons, but he was just waiting, in case she showed up hungry. These males are often so devoted to their chicks, and we believe this one is a parent for the first time. I told him what a great job he had done….I was so touched by his care for this chick, until the very end…tho his nest building skills could use some work!!!! Ha ha! We hope that he and his mate both survive and return for another year at this site.

I savor these final days and hours I get to spend with them….no longer having to rush off to check 15 other nests…just relaxing with them, watching listening and feeling the love. I never tire of spending time with them….It remains a priority until I can no longer find any ospreys. They are so magnificent and even tho it’s been a very tough year, with many heartbreaking losses, in these final moments, all I can feel is the love. What a privilege it is so share a bit of their lives as I do.

September 25!

 I just had to go out looking again today…September 25, and I spent a joyful 2.5 hours watching this lovely chick and her Dad. I didn’t get any photos of him as he was moving around a lot. This sweet juvenile was following him, perching nearby and hollering for food. Dad disappeared for a while and this chick did try to catch a fish! She was gazing into the water, went plunging in and got out of the lake… without a fish, but it was a great water start! She is working on her skills! She was flying between the nest and the nearby lake, and I loved the sound of her crying all the way!

Most of our friends are gone now, so it was a total pleasure to hang out with this pair on this lovely fall day! Oh how I will miss them!

Concerning update…

 It’s become so difficult to write these updates recently. So many sad outcomes. Where do I begin, what do I say? 

I have many situations I could write about. I hinted at them in previous posts.

But the latest sad situation is at the Arboretum cam nest. The banded male, MS was last seen last Monday (8/26) right before a storm came thru. We do not know what happened to him. He was never seen again. The mom was seen that morning, and she too was never seen again. Females are the first to leave on migration so perhaps she is on her way to her wintering grounds. Males do not begin their migration when there is still a juvenile depending upon them for food. The chick was seen on the nest for a few days after dad’s disappearance but on Thursday Aug 29 the chick appeared to have some large bird chasing it. He landed on the nest then almost rolled off the edge of the nest as if he was being dive-bombed and we could see him fly off, followed by a large dark shadow on the ground. The chick was never seen again. I have searched for him to no avail. A new unbanded male has been hanging around on the nest since the territorial male, MS, disappeared. I have witnessed a bald eagle chasing him repeatedly as I searched for the chick and MS. I am beginning to come to the conclusion that the chick may have been killed by an eagle.  I wonder if MS met the same fate, or was he injured in the storm? It wasn’t that bad a storm and ospreys are quite good at surviving bad weather, but I just dont know. So many questions. What we know for a fact is the male has not been seen since Monday in the late afternoon and the chick has not been seen since Thursday morning. Typically a male will stay around and defend his territory and protect his offspring, but he hasn’t. And a juvenile will return to the nest to be fed for up to 4 weeks post fledge. Sometimes they may be fed at a different location, and some will venture forth and begin to try fishing on their own. So far, all searching has been unproductive.  I cannot see or hear a juvenile asking for food. I have looked all around the area and surrounding lakes. The sudden disappearance is unusual, and the final video of the chick is disturbing. And the Dad would not leave his territory before the offspring. Adult males are typically the last of the family to begin their migration, staying until the chicks are no longer asking for food, and have begun their migration. 

And if the territorial male, MS, were still around, he would not be allowing the new unbanded male to remain on the nest as much as he has. 

This is all unsettling. We have so few facts, but we know that three  ospreys are missing for sure. The female may be fine and on her way south as many females are now. But the sudden absense of the territorial male and the beautiful chick is cause for concern. And the presence of a new male is a signal that this is now an undefended territory. Now the cam is down or off so we cannot monitor events on the nest. Since it’s been a holiday weekend, all the gates were locked so I could not look near the nest for any injured birds or bodies / clues. I have been looking for the chick and Dad out side the fences, and listening for them, but I do all this with a deep pit in my stomach. I will expand my search area today. And this is just one of many situations of concern, just one place where I have spent so much time searching, watching, listening. More posts to come.

Thanks to Sunnie Day, a long time, very experienced osprey monitor in another state for the video and tips about these missing ospreys. I had been busy searching for missing ospreys in the other side of the metro.

https://www.youtube.com/watch?v=GIA4eBLBv3E