Monday, June 17, 2013

Falcon ID 101

Firstly, I apologize for not posting before now but there were problems with the blogspot website that would not allow me to log in all day today and Friday just got too busy to get this all down.
There still have been no reports of Zoom, and, while fans might be disappointed with that we do consider it a good sign and continue to assume all is well. It is very possible we may never see her again at the ledge. In some cases fledglings may show back up briefly or hang out at the ledge for awhile; in many other cases they do not return.
Some have sent in photos of Durand in the box thinking it was Zoom so I thought I would take this opportunity to cover some of the finer points of peregrine identification so if/when Zoom does show back at the ledge she will be identified quickly and easily by all.
When a peregrine leaves the nest it is pretty much full adult size, so plumage is the best way to determine a juvenile from an adult. In general, adults have a blue/gray head and back with a very light, creamy colored chest with horizontal barring on the belly and on the feathers on their legs. Juveniles have a brown head and back and have vertical streaking on their front and legs.  Also note the streaking is from the throat down.  And, check out the “cere.” This is the upper part of the beak closest to the eyes where the nostril (or more technically “nares” are located). The cere on an adult is yellow and on a juvenile falcon it is blue. Here is a spliced photo of Durand on the left and Zoom on the right to compare:
Also, if you happen to see one or both leg bands that should help you tell one from another. Here are the codes and color combinations of the three birds:
Durand: silver band on the right leg, left leg: black over black band 32/X
Spark: purple band on the right leg, left leg:  black over red band 32/B
Zoom: silver band on the right leg, left leg: black over red band 51/Z
If you still have trouble with ID, don't worry about it so much.  It can take awhile to train one's eye to the details I've described.  The easiest thing for me has been to focus on the blue/gray vs. brown back and the horizontal barring vs. vertical streaking on the front.  Unfortunately going into the "off season" there won't be that much activity on the cams to give us much practice but there is always next year!!  Another way to practice would be to search the web for peregrine images and try your hand (er, eye!!!) at identifying adults from juveniles.  Have fun!