[EBB Sightings] Townsend's Warbler fledgling

Hi all,
I would just like to add a few words of caution about the possibility of the bird in question being a fledgling Townsend's Warbler. 

First, while the species does nest in the Pacific Northwest, it isn't known to do so any closer than about central Oregon. 

Second, the Birds of North America lists the earliest egg date for the species as 24 May and young not expected until mid-June. 

As Phila correctly pointed out, many birds have expanded their breeding range to now include the East Bay. A partial list would include Red-shouldered Hawk, California Gull, Least Tern, Olive-sided Flycatcher, Chestnut-backed Chickadee, Pygmy Nuthatch, Northern Mockingbird, Dark-eyed Junco, Great-tailed Grackle, and Hooded Oriole. I think an important thing to remember, however, is that none of those species appeared suddenly and expanded their breeding range 500 or so miles in one fell swoop. Even with far fewer birders out and about, the spread of the species that apparently began to breed in the East Bay (or Northern California in general) during the 20th Century was well documented. First they reached this area, then they reached this area, etc. If the Townsend's warbler was expanding it's range down the coast I would expect that at least the very active Humboldt birding community would have begun to report them during the summer.

Finally, and I have first-hand experience with this, adult birds can look like very much like fledglings, particularly when they are wet or cold.

I think the most significant point to be made in a case like this is that the nesting of Townsend's Warbler in California would be an event that demands strong documentation. When I say "demands" I don't mean to say that Judi should feel compelled to go back out and obtain photos if she doesn't have the desire to do so. What it does mean is that for this to be of any use to future researchers there needs to be more.

I hope this is taken in the spirit it was intended!

Good birding,
Steve Glover
Dublin 

--- On Wed, 4/15/09, Phila Rogers  wrote:

> From: Phila Rogers 
> Subject: [EBB Sightings] Townsend's Warbler fledgling
> To: "audubon mt.diablo" 
> Date: Wednesday, April 15, 2009, 11:17 AM
> Dear Birders:
> 
> I think Judi Sierra's posting this morning about seeing
> a Townsend's Warbler fledgling along the lower fire
> trail in Strawberry Canyon is entirely credible.  Judi is an
> excellent birder and the cool mixed conifer forest on the
> north-facing slope is a suitable nesting habitat for this
> species which usually breeds further north along the coast
> in conifer forests.  It's important to remember that
> once juncoes and chickadees (and probably certain
> nuthatches) were only winter residents in the Canyon.  Birds
> commonly expand their ranges (re:  Red-shouldered Hawks).
> 
> This rich Strawberry Canyon habitat is another the reason
> for opposing the proposed construction of two
> industrial-scale buildings (totaling more than 200,000 sq.
> ft) in the canyon!
> 
> -Phila Rogers
> 
> 
>       
> 
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