[EBB Sightings] Thrush in Mission Adobe

This morning I birded the park behind Mission Nursery
(site of Vallejo Adobe mission) on Alvarado Niles
Blvd. at Nursery Blvd. in Niles (Fremont). I heard a
thrush calling & wondered if it might be a Swainson's.
The swirling call was always rising as it repeated the
call several times. Do Hermit Thrushes do that in the
spring or is it most likely a Swainson's?

Joe Devine
Modesto, Ca