Letter From Estela Romero: The Overwintering Season Begins


Published: 11/17/2021

Dear friends,

Monarchs start their overwintering phase now.

All young Oyamel seedlings are carefully tended so that they grow to the tall trees needed by monarch butterflies when they reach the Sanctuaries in the States of Michoacán and México, Central México. It takes decades for Oyamel seedlings to grow into the adult trees such as the ones seen in these photographs. Adult Oyamel trees have canopies extending 1.5 meters wide and are over 30 meters tall. As is typical of conifers, Oyamel trees have shallow root systems yet these roots still keep the trees upright, sometimes for hundreds of years. We are so thankful to these trees. 

El Rosario Sanctuary is the largest colony of all Sanctuaries. The tree broughs laden with heavy monarch clusters appear now in a few Oyamel trees. Today, as you can see from the photos taken at the El Rosario Sanctuary, monarchs are beginning to concentrate in high density. Young monarchs born along the migration corridor from Canada and the United States look fresh, young, strong, and dense in body mass and with intense, bright orange-black colors.

“Monarchs are now forming four different colonies scattered around the iconic Los Conejos meadow location in a north-eastern side orientation” -An Ejidatario grandfather explained.

We are grateful to witness this extraordinary phenomenon and to be stewards of the monarch ancestral home here at the Reserve. This season, as in every winter season, the monarch behavior will unfold differently, bringing surprises. I look forward to describing these behaviors in these articles.

Estela Romero

Angangueo, Michoacán, México.


Note to our readers: This article has been edited from the original English version for clarity and readability.

Read the Spanish version of Estela Romero’s letter»