Monarchs Arriving!

Monarchs are slowly appearing at the coastal California overwintering sites and the nearby region as well as throughout the Arizona deserts this week. Weather conditions across their range vary widely by location. Some places are experiencing record high temperatures while others have chilly winter weather settling in.

Western Sightings

Michelle spotted two monarchs in her yard in Oakland, California. “It was good to see these last few. The weather is warm and sunny with milkweed in the garden.”

On November 12, Nate found one monarch in Morristown, Arizona. “Feeding in Garden at Hassayampa River Preserve.” Monarchs are frequently found feeding on Desert (Rush) Milkweed, A. subulata, a native evergreen milkweed in bloom in the Fall as Nate shows in his photo.

Vicky in Santa Margarita, California, saw one monarch on November 14. “One monarch butterfly was in my yard.”

Kathy reported on monarch on November 16. “On a Duranta plant. Laguna Niguel CA.”

California Overwintering Sites

As monarchs arrive for the winter along the California coast, most of the numbers reported have been very low in comparison to even the most recent past two years. Dr. Francis Villablanca, Monarch Alert Coordinator, visited Pismo Beach on Saturday, November 7 to see how many monarchs had already arrived. He was surprised to find only 87 monarchs including one cluster of 62-63 and many singletons. Dr. Villablanca intentionally chose that day because it was the first cold morning of the season with temperatures staying below monarch flight conditions so he could easily spot them.

The Western Monarch Thanksgiving Counts begin this weekend on Saturday, November 14 and run through Sunday, December 6. This is the time traditionally when the most monarchs are present at the California sites. If you live in California or are visiting and would like to participate in the counts, you can find more information here.

Arizona Winter Monarchs

Many years ago, when monarch researcher Dr. Fred Urquhart visited Arizona, he noted that in winter he saw both breeding and non-breeding monarchs. The same is true today and through tagging we are able to learn more about the longevity and movements of monarchs in the lower deserts. At first the number of monarchs moving through Arizona this year looked very low, but towards the end of October a small surge moved through the region. You can see the clustering of sightings on the adult monarch map around the greater Phoenix area.

With continuing record warm temperatures this week reaching the low 90°’s, monarch eggs and larvae have been spotted around town on native evergreen milkweed. Dan shared a photo of some of his larvae on November 17 in Laveen, Arizona. “Attached is a photo of just a few of my monarch caterpillars. I only have 4 milkweed plants but between the 4 have 3 dozen or so (probably more) caterpillars. Saw another monarch butterfly today while tending to the cat's. Also saw more new eggs laid yesterday, needs more plants but they cost over $20 a piece from the nursery!”

We’ll report our observations as they unfold throughout the season.

Thank you!

This is our final migration report for Western Monarchs this season. Please continue sending in your observations to Journey North. Thank you for recording each sighting to help everyone appreciate the movement of monarchs in the West this Fall! Each report offers a new nugget of understanding and we are very grateful for your participation. We plan to report monthly updates throughout the winter season and your observations can help us all learn more.

Gail Morris is the Coordinator of the Southwest Monarch Study (www.swmonarchs.org), a Monarch Watch Conservation Specialist, and the Vice President of the Monarch Butterfly Fund and the Central Arizona Butterfly Association. The Western Monarch Population News is based on comments provided to Gail Morris. We hope to increase the number of sightings and therefore photos and comments entered into the Journey North. We rely on the volunteers who communicate regularly with Gail and who agree to participate in our effort to increase awareness of the population of western Monarchs. You can reach her at gail@swmonarchs.org.