First Arrivals Within the Biosphere Reserve!

Eastern Monarch Population

First Arrivals in Cerro Pelon

Exciting news! The first wave of monarch arrivals within the Monarch Butterfly Biosphere Reserve were spotted in Cerro Pelon Sanctuary on October 23. This is an early arrival date in comparison to years past.

Ellen in Donato Guerra, MEX: “The Butterflies & Their People forest guardians counted 13 monarchs total flying far overhead the State of Mexico side of the Cerro Pelon sanctuary from 1:35-2:05 pm today.” (10/23/2020)

Estela Romero’s Second Report of the Season: Monarchs’ Triumphant Return

Monarchs have also begun to arrive near the Sierra Chincua and El Rosario Sanctuaries. As Estela Romero writes, “We all watched as the monarchs quietly but determinedly glided into view, appearing in our bright blue sky! … This is the earliest we have seen monarchs arrive. We did not expect their arrival so soon.”

Read more Estela Romero’s second report of the season: Monarchs’ Triumphant Return.

Fall Roosts and Peak Migration in Guanajuato, Mexico

Journey North citizen scientists in Acámbaro, Guanajuato, a city just north of the Biosphere Reserve, are reporting large fall roosts and peak migration activity. These monarchs will soon make their way to the sanctuaries farther south.

Gilberto Ruiz Parra in Acambaro, GUA: “Found roosts [about 2,000 monarchs] in 30 eucalyptus and salt cedar trees.” (10/24/2020)

Oscar Alejandro in Acambaro, GUA: “Mariposas Monarca volando de Oeste a Este, vuelo a unos 25 metros sobre nivel de calle, en momentos el flujo era de 25 Mariposas cada 2 segundos, flujo normal de 4 monarcas por minuto.” [Translation: Monarch Butterflies flying from West to East, flying at about 25 meters above street level, at times the flow was 25 Butterflies every 2 seconds, a normal flow of 4 monarchs per minute.] (10/25/2020)

Late Travelers Along Eastern Flyway

In the US, monarch migration is slowing in northern areas but not done yet.

Vidette in Cape May, NJ: “There is ongoing activity here. To have 2-3 dozen moving through my garden all day long along with notable roosting each evening every night is unusual for us this late in the season!” (10/24/2020)

Emily in Sea Isle City, NJ: “I saw around 10 or more Monarchs this afternoon while I was biking around the boardwalk! I didn’t know so many were still in town this late in the month so I was surprised to find them.” (10/27/2020)

Gulf Coast Activity

Brian in Point Clear, AL: “Likely more than counted (65). Adults stack up here every year at this time on lemon bottlebrush (Callistemon citrinus) as they migrate south.” (10/24/2020)

Western Monarch Population

Fluctuating Weather Conditions

It’s been a mixed bag for monarch migration out west. As Gail Morris writes, “Winds from the north helped monarch numbers explode in the greater Phoenix area in Arizona this past week along with sunny days and warm temperatures. Monarchs also were reported in New Mexico and California and near their migration destinations. But as this new week dawned, a drastic change in weather conditions in the Southwest snuffed out further migration movement.”

Craig in Gold Canyon, AZ:  I’m new to this site (and to Monarch Butterly watching). This beauty appeared today.” (10/24/2020)

Violet in Greenfield, CA: “Flying in the parking lot at Mee Memorial Clinic in Greenfield, CA” (10/26/2020)

Read more of Gail Morris’ Western Monarch Fall Report #9

Only a Few Weeks Left!

Only a few more weeks remain for tracking the fall migration of monarchs. Keep watching and reporting! And remember to keep your eyes peeled for monarchs a few weeks after your last sighting – stragglers may yet come through.

Thanks for all you do on behalf of monarch tracking.