Black-and-White Warbler, Milwaukie Oregon, January 2015

January 09, 2015  •  10 Comments

I watched eBird alerts of this bird come across my desk for a few days before I got off my butt to look for it. What I found from talking with the bird watchers during my nearly 3 hours on site was that most were unaware of OBOL.

I was lucky enough to make the acquaintance of one gentlemen who'd told me that he'd been watching birds for the better part of 60 years and he didn't understand all the fuss I was making to try and get him into position to see the Black-and-White which he was already very familiar with! He spoke with great energy about his two tours of duty in the Coast Guard patrolling Antartica in the late 50's early 60's. 

The bottom line is that I dismissed the eBird reports of this bird principally because I did not recognize the names of the first observers, and I therefore concluded that they were most certainly mistaken about this ID.  Shame on me!  

Having said that, I gratefully acknowledge the fact that had it not been for the presence of a well known, respected, bird guide from n.e. Oregon, I would have never gotten on this bird in the first place. After he and his mom left, I was the expert so long as I was standing there by myself :-) So there you go! 

This is a great bird for Clackamas County, Oregon in Winter, Spring, Summer, or Fall. Go find this bird if you can. At best, you'll likely meet a bunch of wonderful people happy to share their knowledge with you. At worst - you'll find this bird, check it off your list, and then move on. 

Zoom-in (all the way) to get the exact location of a reliable point to find the warbler, that is, if you're patient.

Black-and-White Warbler:

According to my study; (read no prior contact with this species in the field) its pale lores and buff-colored flanks suggest this is a first year female. But I was wrong - see the comments at the end of this post for a detailed explanation.

Four Images:


A nice look (for me at least) of a member of the Myrtle population of Yellow-rumped Warbler:

A Sharp-shinned Hawk which flew in and killed the party for about 20 minutes:

Townsend's Warbler:

Brown Creeper:

(the one that got away)

Area Images:

I found this the most reliable spot to locate the Black-and-White Warbler:


Maureen Kenney, Clackamas County Water Environment Services(non-registered)
The Kellogg Good Neighbor Committee, City of Milwaukie and Clackamas County Water Environment Services are working together on a landscaping project designed to beautify the environment and help control odor. In early 2015, in advance of the spring bird nesting season,1000 new shrubs and 250 new trees will be planted around Kellogg Creek Water Pollution Control Plant.

To allow time for bird enthusiasts to view an unusual migratory Black-and-White Warbler, tree removal for the Kellogg Landscaping project was delayed. To offer the bird a chance to move on, tree removal will now start today with designated trees on the northeast corner of the property—crews will proceed clockwise and conclude at the western border.

For more information, please visit:


Maureen A. Kenney, Community Relations Specialist
Clackamas County Public and Government Affairs | Water Environment Services (WES)
Maureen Kenney(non-registered)
Good Afternoon, I am with Clackamas County, Water Environment Services and am creating a flyer/sign re: our impending landscaping projects and adjustments thta we have made in light of the arrival of the Black-and-White Warbler. Wondering if one of you might be open to allowing us borrow one (1) good photo of this bird for use in our flyer? We would, of course, provide you with a photo credit. Thank you for your consideration. Maureen
jack williamson

I have to admit that I was totally confused and previously thought a second year bird had passed its first birth (hatch) date. The timing and sequence of the molts is still pretty fuzzy to me but your explanation has really helped. Thank you very much!
Dave Irons(non-registered)
Bob Archer is correct. Your Townsend's Warbler is a young (AHY) male. The black shafts running all the way down to the white tips of the median coverts is only shown by HY and AHY birds. Once this bird goes through its first prebasic molt next fall the black shafts will be gone.
Dave Irons(non-registered)
Jack, for the sake of clarity and lessening the aging confusion, a first-winter and second-year bird can be one in the same, which is the case here. When this bird hatched in May/June, it grew its first complete feather set. Then, sometime in late summer/early fall it went through what is called a preformative molt. Unlike the complete fall molt (prebasic molt) that after hatch-year birds undergo each fall (all feathers replaced), the preformative molt is partial with the juvenile flight and many wing covert feathers being retained for more than a year. As pointed out by Dennis Vroman in his comments on OBOL, the retained (older) flight and covert feathers will generally look more worn and faded than those feathers (some coverts and perhaps some of the secondaries) that were replaced during the preformative molt. The obvious differences in the appearance of different generations of feathers are called "molt limits." Late hatch-year (HY in banding references) and after hatch-year (AHY in banding references) passerines normally show these molt limits until they go through their first prebasic molt about 15 months after their hatch date. Finally, and this is the part that is confusing, the "hatch-year" of a bird refers only to the period running from the hatch date (i.e. June 2014) until the 31st of December of the year it hatched (i.e. 31 December 2014). Once the new year turns the bird is considered AHY and confusingly in its second year even though it is merely six months of age. When Dennis called this a "second year" that is what he meant. This Black-and-white Warbler is only about 6-7 months old, but it is in its second year. It is done this way because we have no way to know exactly when a bird hatched or when it goes from being a one-year-old to a two-year-old. Once a bird goes through its first prebasic molt at about 15 actual months of age, it can no longer be aged in years. Such birds are referred to by banders as "after second-year" (ASY). I know this is a long and perhaps tedious explanation of how bird age classes are discussed. Hopefully this helps. In 2010 I published a three-part discussion on this topic. It includes some helpful photos:
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