David James: On May 26 I posted this in a message about my observations of migrating Monarchs along the Trinity River in N California:
“If northward-migrating Monarchs travel about 30 miles a day (as they seem to do on the southward migration) we could expect northern California Monarchs to reach Washington State in about 12 days (first week of June). In the past 3 or 4 years (at least) monarchs have appeared in Washington State in the first week of June”. Seems they moved a little faster with the first reports of Monarchs in the Portland, Oregon-Vancouver, Washington area coming during 30-31 May! Two Monarchs were seen in Portland backyards and another was seen at Lacamas Prairie Natural Area just north of the Columbia River and east of Vancouver, Washington. The two Portland sightings were verified by photographs (available at https://www.facebook.com/MonarchButterfliesInThePacificNorthwest) and the Lacamas Prairie sighting was made by an experienced observer.
In addition, a Monarch was sighted 200 miles further east along the Columbia corridor near Pendleton, Oregon on May 30. The sightings of Monarchs in the Portland-Vancouver area are particularly exciting with relatively few usually seen here. Although we cant totally discount the possibility that these individuals were the result of school/wedding releases, the earlier sightings in N CA, S and C OR and the phenology provide good evidence of a progressive migration northwards. The high numbers of Monarchs seen in N CA (~ 100 in 2 days) and the good number of sightings suggests that the Monarch season in the PNW should get off to a good start!
I now expect to see Monarchs arrive at the central Washington breeding sites that I monitor by the end of this week.
Dr David G James
Associate Professor of Entomology,
Washington State University,
Prosser, Washington 99350