What’s Happening This Week During Spring Migration: April 20

By Dan van den Broek, Educator & Naturalist-in-Residence

As we spend more time at home and in our yards, gardens, local parks, neighborhoods, and local green spaces, we want to highlight seasonal bird activity you can expect to see during spring migration. Join us each week as we show which birds to look out for in your neighborhood and highlight other nature events throughout the year. 

Birds continue to move in and out of Portland as new species start showing up in the next week. A large number of Yellow-rumped Warblers moved through this past weekend with numbers in the tens of thousands being reported in Portland, especially on the buttes and along the Columbia River. Watch for migrants if rain arrives on Wednesday (4/22). This is the time that the southern United States is approaching its peak of northbound migrants.

Species to Watch for This Week

Townsend’s Warbler

The Townsend’s Warbler is one of our most colorful wintering birds and a favorite at bird feeding stations. As spring progresses, Townsend’s Warblers start finding more food away from feeders, and by mid-April they are starting to migrate. At least some of the Townsend’s Warblers that winter in the Portland area head north to breed on Vancouver Island and Haida Gwaii. A new wave of migratory Townsend’s Warblers are now arriving from the highlands of Central Mexico, Guatemala, and Honduras, and their numbers will peak in the next two weeks. Some of these inbound birds will breed in the Cascade Mountains. 

Townsend's Warbler, photo by Mick Thompson

Hermit Thrush

The Hermit Thrush is an uncommon winter visitor in the Portland area. They are often seen hiding in dense brush and spend most of their time on or near the ground. They are occasionally enticed into the open by insects and berries. Numbers pick up as they move through our area from mid-April to early May. Our wintering birds (subspecies guttatus) head north to breeding grounds in the western mountains of British Columbia through Alaska. A separate subspecies (auduboni) breeds in Oregon, and includes coastal mountain breeders that arrive from Baja as well as Cascade Mountain breeders that arrive from Arizona and NW Mexico. Hermit Thrush migration overlaps briefly in early May with the similar Swainson’s Thrush that will be arriving from Southern Mexico and Central America.

Hermit Thrush, photo by Mick Thompson

Purple Finch

Like most finches, the Purple Finch is highly nomadic and concentrates in areas where their preferred food is available. Winter numbers are unpredictable in Portland and most spend the winter to the south of our area. Beginning in March many migrate north from as far away as California.Favorite winter foods include Oregon Ash and conifer seeds and rose hips. However, in the spring they turn to eating flower petals, tree buds, and insects. Watch for Purple Finches passing through neighborhoods and dropping in at bird feeders through early May. Breeders in our area are found mostly in mature coniferous forest where you can hear their rich warbling song emanating from the tops of the highest trees.  

Purple Finch, photo by Mick Thompson

Vaux’s Swift

Though the first Vaux’s Swifts are reported around the second week of April, the main wave of migrants become more noticeable from April 20 through the first week of May. Portland area birds arrive from Mexico, Guatemala and Honduras. A diurnal migrant, large numbers may be encountered during inclement weather, otherwise they tend to migrate very high. Vaux’s Swift will use chimneys and hollowed tree trunks (especially in old growth forests) for both night roosting and nesting. They also have been seen roosting on the outer trunks of trees. Check out www.vauxhappening.org for more about Vaux’s Swifts.

Vaux's Swift
Vaux's Swifts at Chapman Elementary School