[SBB] 3 Bank Swallows in Alviso - 9/18/06

[[[email protected]] (Mike Rogers)]

All,

I spent about a half hour watching the swallow flock near the Alviso Marina over lunch today 9/18/06. Among 90 BARN SWALLOWS were 6 VIOLET-GREEN SWALLOWS, 5 TREE SWALLOWS, 1 NORTHERN ROUGH-WINGED SWALLOW, 1 CLIFF SWALLOW, and 3 BANK SWALLOWS. All the non-Barn Swallows were first fall birds. Note that the young Tree Swallows can be confused with the Bank Swallows since they are almost entirely brown and have variable dusky breast bands. The real Bank Swallows have broad brown chest bands that are the same color as the upperparts (sometimes with a brown spike down the middle of the breast), have pale whitish color curling up behind the brown auriculars (cheeks) and on the forehead in front of the eye, are smaller, and are more prominently edged pale on the coverts and tertials (all three birds today were hatch-year birds).

The young CLIFF SWALLOW was acquiring adult coloration, already sporting a largely rufous throat and a rufous forehead patch. Apparently young Cliffs can show this forehead color without making them a "southwestern" race Cliff Swallow or a Cave Swallow (put Sibley's "Pale-throated juvenile" forehead patch on the "Juvenile", brighten the throat patch a bit, and you have a good match to today's bird).

Mike Rogers
Sunnyvale

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