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Bank or Tree Swallow - Marin County, California, USA (1 Viewer)

rkj

Well-known member
I saw this swallow (or maybe more than one) at Las Gallinas in Marin County, California, 4 June 2022. At the time I thought it was a Bank Swallow (known to some as a Sand Martin), but now I am wondering if it may have been a juvenile Tree Swallow. Bank Swallow would be unexpected at this location. There were certainly juvenile Tree Swallows there and at least one had a fairly distinct breast band, at least in some postures - see the first two photos. But a bird flying around the same area seemed to have a much more distinct breast band - see the last three photos. Other features said to distinguish the two are unclear to me. I would be grateful for any insights anyone would care to share.
 

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KC Foggin

Super Moderator
Staff member
Opus Editor
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United States
For me, the first two images are a Tree Swallow family and the last 3 are Bank Swallows.
 

A2GG

Beth
United States
I agree with KC. One of the young Tree Swallows has a pretty well defined band which makes this more difficult though.
The bird in the last 2 photos has a pretty strong breast band and it has that 'chubby' look of Bank Swallow, so I'll stick with it.
I've only seen Bank Swallows twice, so not a lot of experience here.
 

Microtus

Maryland USA (he/him)
United States
To me, all the birds are Tree Swallows. #3 is a young Tree Swallow; it looks like the ones begging from adults in #1 and #2.

"Juveniles are brown above and white below, but some juveniles and females can show a weak, blurry gray-brown breast band."

I'm not seeing the white swoosh of Bank Swallow on the side of the neck in photos #3-#5, and it looks like there is yellow at the corners of the bill indicative of a very young bird. The darker brown feathers around the eye say Tree Swallow to me.
 

A2GG

Beth
United States
I'm not seeing the white swoosh of Bank Swallow on the side of the neck in photos #3-#5, and it looks like there is yellow at the corners of the bill indicative of a very young bird. The darker brown feathers around the eye say Tree Swallow to me.
I forgot about the whitish 'swoosh' on sides of neck. There doesn't look to be an obvious swoosh in #5. I'm not sure if I see the yellow in the bill, but the breast band does look like it gets more faint in the center. You're probably right these could all be Tree Swallows.

Edit: after zooming photo #5 I can see some hint of yellow in the bill.
 
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A2GG

Beth
United States
Proportions are also better for Tree. Bank are quite slender with narrower wings whereas the in flight images show a stockier, broader-winged swallow more in line with Tree
I've always thought they are 'chubby' and smaller compared to Tree Swallows.

Cornell Lab seems to give conflicting descriptions:

under the first photo it states "small songbird with small head ..."

scroll down under 'Size and Shape' and it states "A small swallow with a chunky body, large head ... "

 

birdmeister

Well-known member
United States
I think of Bank Swallow's head as a little "whale head", almost like a Beluga. Not that it's proportionally large, but its rounded profile gives it that submarine sort of look.
 

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