Female Black-headed Grosbeak, Jackson Bottom Wetlands Preserve, Hillsboro, Oregon on May 19, 2010 by Greg Gillson.
Spring migration seem to be waning at Jackson Bottom Wetlands Preserve in Hillsboro, Oregon. Fewer migrant birds than summer residents were detected this week. Of note was a rare FORSTER'S TERN that passed through on May 14. New migrant arrivals this week included SWAINSON'S THRUSHES and WESTERN WOOD-PEWEES. High numbers of BLACK-HEADED GROSBEAKS continue to pass through (including the female photographed during a shower on May 19).
During calm mornings the soft lisping songs of YELLOW WARBLERS are heard in the willows. These birds are generally quite uncommon in western Oregon. On the free Wednesday morning bird walk this week we heard 5 singing male YELLOW WARBLERS on the Blue Heron Trail and 2 additional birds on the Kingfisher Marsh Trail. The Wednesday morning bird walks are from 8:30 to 11:00 am. No pre-registration is necessary, just meet on the back deck of the education center for a leisurely 3 miles stroll.
The week ended with cold, windy, rainy weather, thus the total number of birds detected this week is perhaps lower with fewer birders reporting sightings.
An AMERICAN ROBIN is setting on a nest in the viewing shelter. BARN SWALLOWS are nesting under the footbridge. A fledgling RED-WINGED BLACKBIRD was noted, as well as a used nest of that species. A brood of MALLARD chicks was noted, along with CANADA GOOSE families. Several fledgling LESSER GOLDFINCHES have been noted.
Here is this week's list of birds sighted.
Great Blue Heron
Northern Rough-winged Swallow