Date: 05/25/2015

Number: 1

I spent the Memorial day weekend along the Trinity River in the Trinity National Forest in N California, about 17 miles west of the town of Mt Shasta, as I have for the past 3 Memorial day weekends.

On each of these weekends my purpose has been to record the abundance of Monarchs in the area. During 2012, 2013 and 2014 I counted between 10 and 25 Monarchs during the 2 days. This past weekend my total was 102!

Monarchs were abundant enough to be observed migrating north along the river at a rate of about 5 per hour during the afternoon (jn the company of northward-migrating California Tortoiseshells and Painted Ladies). The majority of individuals were in good to excellent condition and of 8 females I palpated for the presence of spermatophores, only one was positive. However, some Monarchs in habitats slightly away from the river were clearly reproductive with many ovipositions observed. Eggs were commonly found on Showy and narrow-leaved milkweed as well as a few first instar larvae.

Thus, Monarchs in the area were either reproductive not showing directional flight or non-reproductive showing northward movement along the river. A friend and I tagged 21 Monarchs during the weekend, most of these were likely migrants, so hopefully one or two may be found at points northward.

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.
So if you're in northern Oregon or southern Washington, please watch for Monarchs in the next two weeks and particularly look for a hindwing (ventral) white circular tag!

It remains to be seen whether the populations we see in the PNW this summer will be larger than the past few years, as they currently are in the Trinity NF, but the signs are very hopeful!

Courtesy of Monarch Watch

Trinity National Forest, CA

Latitude: 41.3 Longitude: -122.3

Observed by: David
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