SWAINSON'S THRUSH


Sylvia Sykora
 

How late do Swainson's Thrush remain here in autumn? I've had one coming to the water, morning and evening, all week, latest today, Thursday, September 1.

Sylvia Sykora
Oakland
nr. Skyline and Castle


Bob Power <rcpower@...>
 

Sylvia,

This may or may not be helpful, from PRBO's species account (yes, I know -- Pt. Blue).

Departure date from breeding grounds: According to McCaskie (1988), departs Coast and Mountain regions late August through October. PRBO banding data for Marin County (1996 and 1997) -- latest capture dates October 16, 1996 and October 4, 1997.
 
Spring and Fall migration period: While SWTH is rare in Interior and Basin regions during the summer months, abundance peaks in Spring (April through May) and Fall (August through September) in these regions (McCaskie 1988) -- possibly indicating peak of Spring and Fall migration period in California.
---------

And at the same time, we're on the front end of Hermit Thrush arrival dates.

Best regards,

Bob Power
Oakland, CA


Joe Morlan
 

Sylvia,

Golden Gate Audubon hosts a digital version of "Birds of Northern
California" which has useful bar-graphs showing expected arrival and
departure dates.

http://goldengateaudubon.org/wp-content/uploads/PDFs/BirdsNorthernCalifornia.pdf

The graph on page 58 shows Swainson's Thrush to be common through early
September becoming uncommon through the end of the month and rare through
mid-October.

This chart....

http://www.marinaudubon.org/birds-arrival-departure.php

indicates the species departs Marin County in mid-October.



On Thu, 1 Sep 2016 19:30:52 -0700, "Sylvia Sykora slsykora@sbcglobal.net
[EBB_Sightings]" <EBB_Sightings-noreply@yahoogroups.com> wrote:

How late do Swainson's Thrush remain here in autumn? I've had one coming to the water, morning and evening, all week, latest today, Thursday, September 1.

Sylvia Sykora
Oakland
nr. Skyline and Castle
--
Joseph Morlan, Pacifica, CA


Bill Bousman
 

Dear Sylvia and EBB,

Just to add my two cents. The "Birds of Northern
California" is an amazing resource and has more
than stood the tests of time since its
publication. Just to emphasize what Joe said,
the Swainson's Thrush bar graphs on p. 58 shows
this thrush in two roles. The first is its role
as a breeding summer resident in the wet coastal
forests and mountains of northern California and
the second is as a passage migrant both through
areas where they breed and areas where they do
not. If you live on the wet bayside coast of
Alameda or Contra Costa counties where these
birds breed, then the first bar graph is your
best guide, otherwise, the second bar graph will show you when to expect them.

For what it's worth, at the Coyote Creek Riparian
Station near Milpitas, we banded 2458 Swainson's
during the spring passage from 1986-1996 and 1996
Swainson's during the fall passage for those same
years. This is a location where this thrush has
not nested in a hundred years, so these are all
passage birds. For the fall passage the 5th
percentile date for these records was 3 Sep and
the 95th percentile date was 13 Oct (that is, 90%
of all birds came through between 3 Sep and 13 Oct).

Bill Bousman
Menlo Park

At 09:23 PM 9/1/2016, Joseph Morlan jmorlan@gmail.com [EBB_Sightings] wrote:


Sylvia,

Golden Gate Audubon hosts a digital version of "Birds of Northern
California" which has useful bar-graphs showing expected arrival and
departure dates.

http://goldengateaudubon.org/wp-content/uploads/PDFs/BirdsNorthernCalifornia.pdf

The graph on page 58 shows Swainson's Thrush to be common through early
September becoming uncommon through the end of the month and rare through
mid-October.

This chart....

http://www.marinaudubon.org/birds-arrival-departure.php

indicates the species departs Marin County in mid-October.

On Thu, 1 Sep 2016 19:30:52 -0700, "Sylvia Sykora slsykora@sbcglobal.net
[EBB_Sightings]" <EBB_Sightings-noreply@yahoogroups.com> wrote:

How late do Swainson's Thrush remain here in
autumn? I've had one coming to the water,
morning and evening, all week, latest today, Thursday, September 1.

Sylvia Sykora
Oakland
nr. Skyline and Castle
--
Joseph Morlan, Pacifica, CA