05 May 2015 — PNW Migration Update

A turn in the weather put a bit of a damper on last nights trip north.  There were birds in the air, just not many of them — comparatively.  Still no word on our last two holdouts.  But, the Red-eyed Vireos have shown up at their preferred haunts on the Sandy River Delta.

Big flights last night along the Central, Mississippi, and Atlantic Flyways.  Check out Paul’s archived National Radar Composite, and Cameron’s wind map for insight on what made that happen.

Since the flight last night was light to moderate and through some heavy cloud cover, today’s loop is the Hydrometer Classification so the Biological returns stand out.

04 May 2015 — PNW Migration Update

Moderate to heavy migration took place all weekend. New arrivals were everywhere out in the field.  I still haven’t seen any reports for Western Wood Pewee or Willow Flycatcher.  Good numbers of Swainson’s Thrush were out and tonight, in a clear, full moon sky, i heard about a half a dozen nocturnal flight calls in the two minutes i spent listening.

The Atlantic Flyway finally got some love last night.  For a full report head over to Tom’s recap.

01 May 2015 — PNW Migration Update

A high pressure ridge is building just off shore.  The leading edge is not quite here yet so the north winds associated with that are probably a day out.  While that bodes well for the weekend weather it will slow north bound birds down.

Last night under neutral conditions we had some heavy movement and that will bring the next pulse of migrants into the region.

No word on Western Wood Pewee or Willow Flycatchers yet for the Portland Metro area.

30 April 2015 — PNW Migration Update

No tail winds, but no significant deterrents as well.  There was a moderate amount of movement last night and even heavy in patches.

We’re still waiting on reports for Willow Flycatcher and Western Wood Pewee to close out this season.  But with a Blue Grosbeak and a White Wagtail in the area i doubt many will be paying close attention.

 

 

29 April 2015 — PNW Migration Update

Winds are shifting to out of the north and there are cells of showers moving through the area.  No surprise that the migration last night was moderate at best.

A Swainson’s Thrush was reportedly heard in the area and a Western Tanager was seen in the Corvallis area.  Below the gallery is an update list of the migrant watch.  We are down to six species and two of those (Gray Flycatcher and Red-eyed Vireo) are not detected every year.  The Red-eyed Vireo has set up a breeding range locally around the mouth of the Sandy River so it will eventually be reported.

Update: an Olive-sided Flycatcher was reported 4/27.

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          4/26/15

HOUWRE   15-Apr          reported

NASWAR    15-Apr          reported

PASLFL        15-Apr          reported

WILWAR     15-Apr          reported

BLHEGR      22-Apr          4/27/15

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          4/28/15

YELWAR      22-Apr          4/27/15

BULORI       1-May           reported

LAZBUN      1-May           reported

OLSIFL         1-May           4/27/15

SWATHR     1-May           4/28/15 (heard only)

WESKIN      1-May           reported

WEWOPE   1-May           ????

BANSWA    8-May           4/26/15

YEBRCH       8-May           reported

WILFLY        15-May        ????

REEYVI        1-Jun             ????

COMNIG    8-Jun             ????

20 April 2015 — PNW Migration Update

Yesterday in the narrative we had twelve migrants yet to be reported in the Northern Willamette Valley.  To day we are left with eight.  Yesterday there were reports of Yellow-breasted Chat, Yellow Warbler, Hammond’s Flycatcher, Black-headed Grosbeak.  To our south in the Shasta area a Common Nighthawk was reported.

Great conditions, clear skies and a nice tail wind – BOOM!  Heavy migration last night, all night.  The loop says it all.

Take a look at the wind map and you can predict the scenario.  Northeast – shut down.  Mississippi and Central – pile up in Texas and continuation behind the weather.  Pacific – open for business.

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.

27 April 2015 — PNW Migration Update

More Western Kingbirds, first Dusky Flycatcher and Bullock’s Oriole.  I’m sure i’ve missed something over the weekend.  I’m pretty sure a Western Wood Pewee has shown up in southern Oregon.  Anyway, weekends are hectic and with the sun rising earlier it’s tough to do much but get out in the field and tend to chores.

Last night was a bit unusual as a weak little rain cell moved through the area at the time of nocturnal bloom (1 hr after sunset).  So there is no big flight taking off.  Maybe a couple of opportunistic flocks that found a hole in the weather.  But then, after the cell moved through a significant flight takes place at around 1:00 AM (18:00 UTC).  I don’t think i’ve seen that before.  If i have i don’t remember it.  Have a look:

24 April 2015 — PNW Migration Update

Shorebirds continue to move through the area.  Found in those isolated spots with suitable habitat. I don’t think anything new, that hasn’t been mentioned earlier, has shown up in the area.  But i’ve been quite busy with other tasks and i may have missed something.

Take a look at the winds aloft plot and you can see a concentrated low has formed bringing cold air out of the Gulf of Alaska and turning the winds to a more favorable direction for northbound migrants.

Unfortunately there are associated rains and that always dampens determination.  But give a bird any break in the weather and they will take advantage of that.  I put in the HC plot today so it is easier to pick out the birds from the weather.  It looks like they had a few hours of flight before giving up for the night.

If you look again at the winds aloft plot one might surmise a continental scenario:  looking good for the Central Flyway, and not so good for the Atlantic.  So i put in a snapshot of the National Radar Composite to see if that is how it played out last night.

Winds Aloft Plot: Source

National Radar Composite: Source

22 Apr 2015 — Migration Update

As predicted yesterday the north winds kept migrants grounded last night.  It looks like these conditions may hang around for a while too.  I have a capture of the situation in today’s gallery.  But i encourage anyone looking to get a handle on atmospheric conditions to visit Cameron’s website here.

A few more reports for the Portland Area: Lazuli Bunting, Western Kingbird, Warbling Vireo, Nashville Warbler.