PNW Migration Update — Narrative

I haven’t been keeping meticulously close attention to migrant arrivals this year so I thought I would put together a checklist of the 40 spring migrants moving through or coming into the Northern Willamette Valley of Oregon.

Using the data I compiled last year from eBird I ordered the migrants using the frequency data from earliest to latest arrival. The eBird data can be found in the header banner under “eBird Frequency Data”. I didn’t use the earliest arrival, nor would I say I used the mean. It’s probably somewhere in between but a bit closer to the earliest arrival.

For the four species that also winter in the area (Hermit Thrush, Yellow-rumped, Towsend’s and Orange-Crowned Warblers ) I picked the date when the frequency data jumps indicating migrants are moving through.

For the three species that are detected at very low levels (Gray Flycatcher, Bank Swallow, and Red-eyed Vireo) I just picked a date, but not the earliest.

Since eBird frequency charts are blocked out in four segments per month they assign the data to the 1st, 8th, 15th, and the 22nd of each month. So that is how it is presented here. This is equivalent to thinking of arrivals occurring sometime during the 1st, 2nd, 3rd, or 4th week of the month.

Each species is designated by a six letter code to save space. These will be intuitively obvious to any regular field observer. Not everybody will be able to decipher these codes so here is a link to a listing of the codes. Enter the alpha code into your browser search function and it will show you the name of the species.

Below is the table with my recollections of this year’s arrivals for the Northern Willamette Valley:

Specie         Sig Freq

TRESWA     15-Feb          reported

TURVUL      1-Mar           reported

RUFHUM   8-Mar           reported

VIGRSW     8-Mar           reported

BARSWA    22-Mar         reported

ORCRWA    22-Mar         reported

CLISWA       1-Apr            reported

COMYEL     1-Apr            reported

NRWISW    1-Apr            reported

BTGYWA    8-Apr            reported

CHISPA          8-Apr            reported

HERTHR      8-Apr            reported

YERUWA    8-Apr            reported

CASVIR       15-Apr          reported

HAMFLY     15-Apr          ????

HOUWRE   15-Apr          reported

NASWAR    15-Apr          reported

PASLFL        15-Apr          reported

WILWAR     15-Apr          reported

BLHEGR      22-Apr          ????

DUSFLY       22-Apr          reported

GRAFLY       22-Apr          ????

HERWAR    22-Apr          reported

MACWAR  22-Apr          reported

PURMAR    22-Apr          reported

TOWWAR  22-Apr          reported

WARVIR     22-Apr          reported

WESTAN     22-Apr          ????

YELWAR      22-Apr          ????

BULORI       1-May           reported

LAZBUN      1-May           reported

OLSIFL         1-May           ????

SWATHR     1-May           ????

WESKIN      1-May           reported

WEWOPE   1-May           ????

BANSWA    8-May           reported

YEBRCH       8-May           ????

WILFLY        15-May        ????

REEYVI        1-Jun             ????

COMNIG    8-Jun             ????

So, we have twelve species that I can’t recall being reported in the Northern Willamette Valley – but I’ve not kept up with all of the reports. Nor have I kept a record of when each reported species was first reported.