Thursday, March 26, 2015

While we are waiting...

Many people are asking about the chicks they watched last year. Most juveniles do not return to  their summer territories until they are two or three years old. I have seen a one year old osprey once in my 21 years of studying them. (I am beginning my 22nd season of osprey watching!) We do see quite a few two year olds and have published some observations about their behaviors. Most males return to within ten km of their natal nest, while females often go further away to nest.  This may be natures way of preventing inbreeding. Having said that, my observations indicate that some females do return to nest very near their natal nests. On the flip side we have had males nesting very far from their homes. We had a male from Michigan nesting here in Minnesota!  We have also had a female from Ontario nesting here, as well as females from Ohio, Iowa and Wisconsin. Our females have shown up in other states also, such as Michigan. 
It is the urge to breed that usually brings them back from their wintering grounds and juvenile wanderings. The literature indicates that Ospreys do not breed until they are three years old, but I have seen two year old males attending nests where chicks have hatched. Since paternity tests have not been done we do not know if those chicks were genetic offspring of the attending male. I have documented quite a bit of extra pair copulation among Ospreys which could explain the chicks (I co-authored a paper about this which was published in the Journal of Raptor Research in June of 2008). Even more interesting is that I have documented a two year old female who laid eggs that produced chicks successfully! So they may be able to breed at younger ages than was previously thought. So there are some fun observations that have come from this research, to shed some light on osprey behaviors as we await their returns. You never know what you are going to see! That's what keeps me going!

Monday, March 23, 2015

Another card from an Osprey...

Ah well, I got another card today from an osprey in South America...said he is heading north, can't wait to see us, Minnesota is so nice this time of year...and he included a gas gift card from the North Metro Ospreys! I can't quite tell from the photo who he is...but we are narrowing it down! Thanks to whoever helped him mail the card!!!!!

Saturday, March 21, 2015

Osprey season has begun!

The first Osprey has been sighted! So it's time to begin checking some nests! Keep looking up, checking those lights and cell towers, and please, please, please, report new nests to us by emailing osprey.mn@gmail.com!

Friday, March 20, 2015

2014 Summary...

Here is the 2014 summary...
The 2014 Osprey season in the eight county metro area surrounding Minneapolis and St Paul began late after a very long, cold winter. We did receive reports of Ospreys as early as March 1, but we were not able to confirm any Osprey sightings until April 6. Some eggs were laid unusually late and there were chicks which did not fledge until late August. The adult male stayed and cared for these late chicks for a full month, not departing until early October. The overall number of known occupied nests dropped this year. (There may be more nests we do not know about.) There were 12 nests which were occupied last year but were empty this year. Four pairs from those nests moved to a new nests and six additional single birds moved to a new nest with a new partner. There were 101 nests which were occupied* by a pair of adult ospreys. One additional nest had only a single osprey observed. Eggs were laid in 89 nests (94 in 2013) and 71 of these nests had at least one chick that was confirmed to have fledged successfully or survived to fledging age (70 in 2013). There were 30 nests which failed (33 in 2013). There are two distinct subcategories under failures; nests where a pair was present but no eggs were laid (12) and nests where eggs were laid but they failed to successfully fledge a single chick (18). (Not laying eggs is considered to be a kind of nest failure.) There were three additional nests, discovered late in the season, where it was not known if eggs were laid or not, but no chicks were ever observed. There were 126 chicks that were known to have fledged successfully or survived to fledging age. There was a high mortality rate in 2014 with 33 additional chicks which were known to have died or disappeared before fledging. Three adults also died or disappeared midseason; two from one nest and another at a nest very near. There were 94 adult Ospreys identified by their bands. Two of these were from Iowa, one was from southern Ontario. There were only 9 new nesting territories that we know of. Only three of these new nests successfully fledged chicks. There were 9 banded Ospreys which were believed to have bred successfully for the first time and their average age was 4.10 years old. (Average age of first successful breeding for males this year was 4.29 years and for females it was 3.67 years).
The overall productivity of occupied nests which were successful this year was 70%, (67% in 2013, 77% in 2012, 70% in 2011, 73% in 2010). The mean number of young fledged per successful nest was 1.77 (2.08 in 2013). The mean number of young fledged per active nest was 1.41 (1.55 in 2013) and the mean number of young fledged per occupied nest was 1.25 (1.39 in 2013). These numbers reflect a drop in productivity per nest, largely due to the high mortality rate. The causes for the mortalities are not clear. A few losses can be attributed to storms, but many cannot. Swarming of black flies were observed at some bandings and one chick that was being viewed on a web cam, seemed to have jumped to its death to escape the flies.
Vanessa Greene
(Any use of this data should have its source appropriately acknowledged.)

soon...

I know many of you are anxious to see our Ospreys back on their nests. Migration studies have shown that they often make their turn trip in a shorter time than the fall southerly migration. They are fueled by hormones. The older experienced Ospreys, who have bred successfully in the past, seem to know that the sooner they return to defend their territory, fix up the nest and get the eggs laid, the better chance their offspring will have for survival. The more time the young ones have to build their skills and prepare for the first migration, the better. This year in Minnesota, they will not be hampered as much as last year by frozen lakes and deep snow. Any day now...

Friday, March 13, 2015

2014 ACKNOWLEDGEMENTS...

There are so many people who have been instrumental in helping Twin Cities Metro Osprey Watch continue this Osprey research. A very special thanks to Alice Stoddard and Barb Ankrum for their steadfast help, support and encouragement. You have no idea how much it has meant to me personally and to the research. It is not always easy to keep going and you both have supplied needed inspiration with your passion and dedication. Many thanks also to Sonja Axness, Dick Allen, Don Steinke, Perry Westphal, Bruce and Virginia Bernin, Faith Christine, Margaret Wurtele, Ellie Crosby,  Grace and Roger Pass, Phyllis Bofferding, Debbie Engelmann, Jim Radford, Larry Waldhauser, Tedd Clauson, Tom Morris, Krista Wilkowske, Marty Osborn, Jason Bolish,  Karen Connolly, Derek Burns, Melinda Grahl, Margaret Hutchinson, Tom Schmelzer, Sean and Karen Akins, Meriah Jacobs-Frost, Lee Bakewell, Steven Steinborn, Luke VandenBergh, Linda Radimecky, Carol  Fischenich, and Mary Meyer, for sharing their observations, their committment to this effort, their photos, and their love for these birds with me. Thanks to Tom Burrrows at Aggregate Industries, Mary Lee and Janice Hawkins at the National Guard, Roger Stanton at Bolander Construction, for all their cooperation in allowing me to monitor nests.
Thanks to Marlyn Anderson for technical assistance with computer issues and data organization. 
I am sure I have forgotten someone and I will post an addendum when I remember!

A very special and heartfelt thanks to Virginia and Bruce Bernin, Don Stienke, Perry Westphal, and Jo Beuhler Maltman, for their financial donations which helped me continue this research.

And finally a thanks to all the osprey fans around the world who have written to me, hit the "like" button, shared their stories, enthusiasm and love for these birds and generally offered support in ways that cannot be described. I appreciate all the kindness and camaraderie. 


Vanessa Greene

Mid March...they are on their way...

Here it is mid March. I know many of you are anxiously awaiting the return of our winged friends. I want to once again, express my gratitude to all who helped me watch over all the nests last year. I am hoping you will all return this year to document all the milestones, behaviors, nesting success or failure and those precious chicks! Please drop me an email if you intend to watch your nests again. If there are new people who would like to jump in and adopt a nest or two to watch over this year, also drop me an email so we can decide where to plug you in. We always need help monitoring this growing population of Ospreys! I will have some new posts soon with final numbers from last year and acknowledgements of all the wonderful people who contributed so much. I am still putting on the finishing touches and rechecking data one more time. There is so much data collected and so much to pull together! 
So keep your eyes to the sky and stay tuned!