Scott is correct about the difficulty of sexing and identifying individual ospreys. Their markings can increase in size with age and there are ample males that develop necklaces over time. The most reliable way to sex adults is by their behavior.
However, it is possible to use the marking patterns on the dorsal aspect of their heads (top and back of neck) on mature ospreys to distinguish individuals in the field, but it takes repeated observations, lots of practice, and photographic evidence. There are slight variations in the size, shape, and number of dark markings on most individuals that are visible at rest or when seen from above. However, in flight, these markings are not visible. I've used this method to identify the Salt Point osprey pair with certainty since 2013. I can also track their local movements around the Salt Point/Myers Park area by car, but once they leave the immediate area and my line of sight, I cannot follow them. Since there are many ospreys in the area, especially at the beginning of the season and when their are intruders about, accurately tracking individuals as they fly over distances can only be reliably done if distinctly banded or by using GPS/GMS tracking. Candace *See* "Field Identification of Individual Ospreys Using Head Marking Patterns," J. Wildlife Mgt., Bretagnolle, Thibault, and Dominici, vol. 58 no. 1, 1994, pp. 175-178. On Thu, Apr 9, 2015 at 11:11 AM, Scott Haber <[email protected]> wrote: > The "necklace" is not really a reliable method for sexing Ospreys in the > field. Males can and do show the "necklace", and there's lots of overlap. > As Alan Poole states in the BNA account, "sexes often difficult to > distinguish in the field. > > Furthermore, it's quite a stretch to take a bunch of generalized, common > behaviors that almost all Ospreys would display, and assign them to a > particular individual because one feels it's their "fashion". > > It's nice that folks are so interested in the local nesting pairs, but > perhaps it's wise not to go overboard with assumptions about how much we > know about individuals unless we're reading band numbers off of them like > with the campus Red-tails. > > -Scott > > On Thu, Apr 9, 2015 at 10:57 AM, Karel V. Sedlacek <[email protected]> > wrote: > >> David, >> >> >> >> Thank you for your thoughts. >> >> See my comments below. >> >> >> >> Karel >> >> >> >> *From:* Dave Nutter [mailto:[email protected]] >> *Sent:* Thursday, April 09, 2015 10:31 AM >> *To:* Karel V. Sedlacek >> *Cc:* CAYUGABIRDS-L >> *Subject:* Re: [cayugabirds-l] Olin the Osprey is back >> >> >> >> This nest platform is installed atop one of several poles for lights for >> McGovern Fields, replacing (literally) a nest which Ospreys built atop the >> same pole, right? McGovern Fields occupy the NE corner of the fields >> between East Hill Plaza, Ellis Hollow Road, Game Farm Road and Cascadilla >> Creek with the east end of the East Ithaca Recreationway. >> >> KVS—The 2014 nest was atop the south center, double-side light pole at >> the McGovern Fields. This caused the lights to be turned off for the >> duration of the nesting season. Plans were made for a replacement location >> and through the efforts of a lot of folks a riser, built by the Musco >> Lighting Co was installed on the SW tower. >> >> In case other Ospreys start nesting near Game Farm Road, maybe refering >> to McGovern Fields would be better, at least until another of those light >> poles gets built upon! >> >> KVS—It is unlikely (that is the hope anyway) that another Osprey family >> will build on another of the poles at the fields—the outside poles are >> single-side, and the center double-sided poles now have bird-deterrents on >> them. In addition, Olin and Olive spent considerable energy last season >> dissuading other Ospreys from the area. Having said that, names are >> flexible and can be adjusted as needed. >> >> The Ithaca reservoir and Commonland are along Six-mile Creek south of >> NYS-79, which is in the next drainage behind Snyder Hill and perhaps >> difficult to see from McGovern Fields, so was that really where you meant >> the Osprey flew? >> >> KVS1—Yes. This was Olin’s pattern of behavior last year when going to >> Common Lands: circle over the tree line to make a threat assessment near >> the nest, fly west down Cascadilla, to East Hill and linger to assess the >> area, then turn south and head towards Six-Mile Creek. Having chased him >> several times this is his typical pattern. When Olive is in the nest he >> can make the roundtrip with a fish in 12 mins. He sometimes does make the >> turn up Snyder Hill Rd. >> >> How do you ID the birds as individuals? Is it an assumption based on >> gender (general plumage and relative size) and presence or behavior at the >> site, or are there specific characteristics of individual birds that you >> use? >> >> KVS—Gender, based on plumage, Olin has no necklace, Olive has the >> lightest Necklace in the southern basin to-date. Olin has a distinctive >> set of markings on the top and back of the head. Absolutely behavior: Koi >> fish raided from Snyder Hill, NW tower, bite the fish, look both ways, drop >> part of fish, flying routes as described above. >> >> I recently saw an Osprey perched beside the platform at the NW corner of >> Newman Golf Course and wondered if that indicated it was being used. >> Moments later I saw an Osprey flying from that direction toward Union >> Fields, so now I wonder if it was one of the Union Fields pair just >> checking it out. I don't know how you keep track of individuals. >> >> Ospreys love to do things after a fashion—you do your best to learn them >> and id based on that. >> >> --Dave Nutter >> >> >> On Apr 09, 2015, at 07:24 AM, "Karel V. Sedlacek" <[email protected]> >> wrote: >> >> First definite sigthing of Olin the Game Farm Osprey Nest male was 7:50 >> AM on the NW tower at GF. He was happily eating a Koi fish. 8:20 AM he >> flew to the new nest riser and flapped, poked around and sat for a few >> minutes. Then off down the tree line west and then south to the reservoir >> or Common Lands. Later, 12:45-1:10 Olin ate another fish and worked on the >> nest. Landed briefly on one of the double sided poles then went to the >> Nest. Mr Lefty, the RTHA was near by both times and appeared at ease. >> >> >> >> >> >> Sent from my Verizon Wireless 4G LTE Smartphone >> >> -- >> >> *Cayugabirds-L List Info:* >> >> Welcome and Basics <http://www.northeastbirding.com/CayugabirdsWELCOME> >> >> >> >> Rules and Information <http://www.northeastbirding.com/CayugabirdsRULES> >> >> >> >> Subscribe, Configuration and Leave >> <http://www.northeastbirding.com/CayugabirdsSubscribeConfigurationLeave.htm> >> >> >> >> *Archives:* >> >> The Mail Archive >> <http://www.mail-archive.com/[email protected]/maillist.html> >> >> >> >> Surfbirds <http://www.surfbirds.com/birdingmail/Group/Cayugabirds> >> >> >> >> BirdingOnThe.Net <http://birdingonthe.net/mailinglists/CAYU.html> >> >> >> >> *Please submit your observations to eBird >> <http://ebird.org/content/ebird/>!* >> >> -- >> >> -- >> *Cayugabirds-L List Info:* >> Welcome and Basics <http://www.northeastbirding.com/CayugabirdsWELCOME> >> Rules and Information <http://www.northeastbirding.com/CayugabirdsRULES> >> Subscribe, Configuration and Leave >> <http://www.northeastbirding.com/CayugabirdsSubscribeConfigurationLeave.htm> >> *Archives:* >> The Mail Archive >> <http://www.mail-archive.com/[email protected]/maillist.html> >> Surfbirds <http://www.surfbirds.com/birdingmail/Group/Cayugabirds> >> BirdingOnThe.Net <http://birdingonthe.net/mailinglists/CAYU.html> >> *Please submit your observations to eBird >> <http://ebird.org/content/ebird/>!* >> -- >> > > -- > *Cayugabirds-L List Info:* > Welcome and Basics <http://www.northeastbirding.com/CayugabirdsWELCOME> > Rules and Information <http://www.northeastbirding.com/CayugabirdsRULES> > Subscribe, Configuration and Leave > <http://www.northeastbirding.com/CayugabirdsSubscribeConfigurationLeave.htm> > *Archives:* > The Mail Archive > <http://www.mail-archive.com/[email protected]/maillist.html> > Surfbirds <http://www.surfbirds.com/birdingmail/Group/Cayugabirds> > BirdingOnThe.Net <http://birdingonthe.net/mailinglists/CAYU.html> > *Please submit your observations to eBird > <http://ebird.org/content/ebird/>!* > -- > -- Cayugabirds-L List Info: http://www.NortheastBirding.com/CayugabirdsWELCOME http://www.NortheastBirding.com/CayugabirdsRULES http://www.NortheastBirding.com/CayugabirdsSubscribeConfigurationLeave.htm ARCHIVES: 1) http://www.mail-archive.com/[email protected]/maillist.html 2) http://www.surfbirds.com/birdingmail/Group/Cayugabirds 3) http://birdingonthe.net/mailinglists/CAYU.html Please submit your observations to eBird: http://ebird.org/content/ebird/ --
