MISSION, Texas (Border Report) — A rare cold front in South Texas last week apparently helped to give clusters of monarch butterflies a boost and they’ve been spotted crossing the Rio Grande south of the border as they migrate back to their ancestral home of Michoacán, Mexico.

Marianna Treviño-Wright, executive director of the National Butterfly Center, told Border Report that many of these colorful orange and black butterflies already have been crossing in clusters on their annual journey in which some travel thousands of miles from the United States.

It’s early for the monarchs, which in Mexican culture are closely affiliated with Día de los Muertos, or Day of the Dead, on Nov. 1.

The Mexican state of Michoacan, west of Mexico City, is where the monarch butterflies migrate.

The Indigenous Purépecha believe that the monarchs represent the souls of their ancestors returning to visit them for Día de Muertos.

Usually, the monarchs are seen migrating from South Texas across the Rio Grande in mid-October.

“It’s a little bit early but that big cold front that came through last week obviously pushed a first wave through. Now the rest of them should trickle through Texas to the coastal areas mostly through Columbus Day weekend,” Treviño-Wright said. “Then the second large wave typically crosses the borderlands and the river around Halloween.”

These queen butterflies are slightly smaller than monarch butterflies and their coloring is more brown with white spots. These butterflies were seen June 21, 2021, at the National Butterfly Center in Mission, Texas. (Sandra Sanchez/Border Report Photos)

But it’s not always easy to spot them.

Treviño-Wright says monarchs typically fly 300 feet up in the air.

“So do pay attention to the skies because you can see rivers of monarchs sometimes flying through. You may also go out in the morning and see clusters of them roosting on the trees and then some may fly through at eye level if they’re looking for nectar or a place to lay eggs still that very last generation that will hatch and then make its way south, also,” she said.