For those who like the numbers and understand the importance of the research, here are the 2022 results…
2022 OSPREY RESEARCH AND PRODUCTION SUMMARY
By Vanessa Greene
The first Ospreys of the 2022 season were reported back on their nests on April 2 and the first bands read by April 3! In this 39th year of monitoring Osprey nests in the eight county Twin Cities metro area, there were slightly fewer nests with a higher failure rate than last year. The early Ospreys laid the first eggs by April 16!
There were 167 nests which were occupied* by a pair of adult ospreys. (170 in 2021). There may be more nests we do not know about and we hope the public will continue to report new nests to us. Eggs were laid in 160 nests (166 in 2021) which is quite a high percentage of occupied nests. There were 132 nests that had at least one chick that was confirmed to have fledged successfully or survived to fledging age (140 in 2021). We documented 35 nests which failed (30 in 2020). We separate failed nests into two distinct subcategories; there were 7 nests where a pair was present but no eggs were laid (4 last year) and 28 nests where eggs were laid but they failed to successfully fledge a single chick or the cause of failure was unknown (26 last year). (Not laying eggs is considered to be a kind of nest failure by other scientists.) Out of those 28 nests where eggs were laid, there were 3 nests where hatching did occur but all chicks died fairly early, before we could accurately count them. The remaining 25 nests failed prior to hatching or the timing of failure was unknown. The 2022 failure rate rose to 21%. This represents a slight increase over last year! (In 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 264 chicks that were known to have fledged successfully or survived to fledging age! (295 in 2021). Most successful nests had two chicks this year, with 74 nests with two chicks, 29 nests with three chicks, and 29 nests that produced a single chick. The mortality rate this year was a bit lower than last year with 23 chicks which were known to have died or disappeared before fledging, (26 last year). Sadly, two of these chicks became tangled in baling twine and suffered tragic, unnecessary deaths (one was dead in nest, the other was hanging alive and was taken to The Raptor center where it had to be euthanized). Two other chicks got a talon caught on the cell tower / lightpole equipment, were rescued, taken to The Raptor Center where they had to be euthanized. There was just one known adult mortality, a female that disappeared leaving a very small chick for the single male to care for. It was touch and go but this young, first time Dad did provide enough care for this chick to fledge successfully.
There were only 50 adult Ospreys identified by their bands, as the number of banded birds continues to drop. We were sad to document that there were 20 banded birds that did not return this year. Only one of the returning banded ospreys was from another state (Iowa).
There were 17 nests that were removed over the winter which was an unprecedented number. Three were on ballfield lights, one was on a power line and 13 were on cell towers. We believe most of these removals may have been related to necessary work on cell towers for the nationwide migration to 5G as this was reported from other researchers around the country as well. We only located 4 new nesting territories with a pair present and two additional nests which had only one osprey observed, with no sign of chicks. This is a big drop in the number of new territories discovered. Of these new nests, 2 of them successfully fledged chicks. It is interesting to note that of the 167 occupied territories this year, 80 were on osprey nesting platforms, 34 were on cell or radio towers, 31 were on ballfield lights, 19 were on a power pole or transmission tower, two were on other manmade structures and one nest was built in a tree.
The oldest male this year, was 19 years of age, with one that was 17 years of age, twothat were 16 years of age and one that was 15 years of age! ALL of these older males bred successfully! Our oldest female was 16 years old, with three that were 15 years of age and all but one bred successfully.
The overall productivity of occupied nests which were successful this year dropped slightly to 79%! (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 was 2.00%(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 was 1.65% (1.78% in 2021, 1.65% in 2020,1.39% in 2019,1.64 in 2018, 1.75 in 2017,1.84 in 2016) and the mean number of young fledged per occupied nest was 1.58% (1.74% in 2021, 1.49% in 2020,1.28% in 2019, 1.51 in 2018, 1.62 in 2017, 1.70 in 2016). These numbers reflect a slight decrease in overall productivity per nest.
It is interesting to note that we have recorded 3,263 chicks that fledged from monitored nests since the inception of this project.
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*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.
