Rockfish Valley Trail 6/13/11

All photos are Marshall Faintich


The ten degree drop in temperature made hiking on the trail a lot more enjoyable this morning. There were a number of the usual summer species, including several juvenile birds. Unfortunately, all of the juvenile (and adult) flies were also out, but the bird show made it worthwhile.


Eastern Kingbird


Eastern Kingbird


Juvenile Field Sparrow


Newly fledged Field Sparrow?

In the Yellow Bird Thicket, a juvenile male American Redstart was preening its feathers, possible trying to rid its first year plumage as its adult feathers came in.


Juvenile male American Redstart


Juvenile male American Redstart


Juvenile male American Redstart

There was an unusual looking Orchard Oriole - probably a female, as a first year male would have a black throat and lores, but this bird had brown feathers on its crown - perhaps a juvenile female showing some of its pre-adult plumage?


Orchard Oriole


Orchard Oriole


Orchard Oriole

The highlight of the hike was a Yellow Warbler (probably a female, but possibly a first spring male) that flitted about from one tree to another, all in close proximity to me, and not bothered at all by me or my camera. I took more than 150 close-up photos, and the hard part was deciding which ones to process and post.


Yellow Warbler


Yellow Warbler


Yellow Warbler


Yellow Warbler


Yellow Warbler


Yellow Warbler


Yellow Warbler


Yellow Warbler


Yellow Warbler


Yellow Warbler


Marshall Faintich: I tend to use the term juvenile when referring to any bird that has not reached adult plumage. I know that the American Redstart shown above was beyond its first year, as I have photographed several first summer males - they resemble a female, but usually have some dark breast spots. A couple of very knowledgable birders e-mailed me on this topic, and one of the e-mails is posted below.

Also in Chris's e-mail is his opinion on the fledgling. At first I thought it might be a recently fledged Red-winged Blackbird, but then changed my mind after comparing it to photos I have taken of juvenile RWBBs. My best guess was Field Sparrow, but only because there were several adult Field Sparrows in the same area. We do have a few Blue Grosbeaks on the trail, and some seen nearby, but not seen on the day I took this photo.


Chris M.: [juvenile Field Sparrow?] What I see that suggest blue grosbeak is, the hint of wing bars, and the large grosbeak like bill. The coloration and facial pattern of this bird in no way resembles the other photos you have of juvenile field sparrows. I mention it suggests a blue grosbeak because I am not entirely sure on this ID, I would expect the grosbeaks to be a bit lighter in coloration. Anyway I do not think it is a field sparrow. Possibly time to put this one up for a vote.

As far as the Redstart, it is neither a second year, juvenile, or immature. That plumage (black and orange) is only found on mature adult male redstarts. After hatching, and after molting out of their down, they molt into their formative plumage (the plumage which resembles females) and retain that until the following fall after their first breeding attempt upon which they will then molt into their black and orange feathers (definitive plumage) which they will take to central America with them and back for the following breeding year (when they will be an ASY bird). It is possible that this bird was a SY bird who has already attempted to breed and gone through it's fall molt into definitive adult plumage although I think its extremely early for that to have happened, and if it had it would then be called an after hatch year (AHY) bird and not an SY bird (but definitely not immature or juvenile).

Redstarts are a bit confusing since they take more than one year to "appear" adult, much like purple finches. We dorky banders, in order to not confuse ourselves, tend to shy away from the terms immature, and mature as this relates to sexual maturity and not molt. i.e. a second year redstart is a sexually mature adult, but does not have its black and orange "adult" plumage associated with being an adult. Instead we use definitive and formative where as definitive plumage would refer to a bird who has reached it's most adult plumage like the one in your photo) and a formative plumaged bird (but sexually mature) would refer to a bird that has not reached that plumage (in the case of the redstart, the male that resembles a female)

Anyway, I hope that isn't super confusing. I find bird molt supremely fascinating as it makes one think of the evolutionary forces behind the molts we see. Let me know if you put that fledgling to a vote. I would be curious to what others say. I cannot turn down a good bird ID quiz!!



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