The Wonder of Monarchs in Mexico

The Monarch (Danaus plexippus) butterflies that have spent the winter in Mexico have now started their northbound trek back to the United States and Canada. People who have visited the sites where the butterflies spend the winter have reported seeing tens of thousands of butterflies.

My friend, Jacqui Knight, just recently returned and shared with me her experience. “I was in Mexico two years ago to see the Monarchs. I was amazed at how many Monarchs we could see in the trees–the experience was mind-blowing. And so I was completely amazed at just how many more Monarchs I saw on this trip.

Jacqui Knight, from New Zealand, is the founder of Monarch Butterfly New Zealand Trust.

“The day after we arrived, we rode up Cerro Pelón, and halfway up the mountain, the horses stopped in a shady passage. Suddenly I realized we were surrounded by a stream of Monarchs, a constant stream, flying towards us and further down the mountain. The stream joined up with another stream as the Monarchs surged down the mountain, looking for nectar sources further down. Some of them stopped nearby to sip at Salvias (Salvia spp.) and other wildflowers beside the track.

“We rode on and found the Monarchs in a clearing in huge bunches in the trees. It was a thrill when something prompted the Monarchs to burst into life. Looking up at the blue sky it was as if I was standing next to a huge bonfire with ashes littering the sky, falling around us.

“And at the very top, the trees were thick with Monarchs. These were harder to see as they sat, wings closed in the trees. But we could see them and hear them: the gentle swish of a wonder of wings in the pines and firs. I had never imagined that I would see so many!

Photo by Brenda Dziedzic, author of Learn About Butterflies in the Garden. (Used with permission.)

“The next day down in the village of Macheros we saw Monarchs flying everywhere looking to top up on their reserves before they began the journey northwards, and they were puddling thickly in a stream near some houses… so many Monarchs that you could hardly see the stream,” Jacqui wrote as she ended her description of viewing the overwintering Monarchs up close.

In support of Jacqui’s description, the World Wildlife Fund, which monitors Monarch numbers, reported, “The area of forest occupied by hibernating Monarch butterflies in Mexico has increased by 144% in relation to last year’s survey—the biggest growth in the past 12 years. A new colony of Monarchs was also found in the Nevado de Toluca, State of Mexico.” This is good news for these North American Monarchs and for those of us who have made efforts to help this iconic butterfly. But we still have a long way to go!

The eastern North American Monarch population estimate for the winter of 2018-2019 reports a population size of 6.05 hectares. Read more:

But the news is not so positive for those Monarchs that overwinter in California. The Xerces Society for Invertebrate Conservation, a nonprofit group that conducts a yearly census of the western Monarch, stated the population reached historic lows in 2018, an estimated 86% decline from the previous year. That combined with a 97% decline in the total population since the 1980s, this year’s count is “potentially catastrophic,” according to biologist Emma Pelto. Scientists estimate that the Monarch butterfly population in western North America has a 72 percent chance of becoming near extinct in 20 years if the Monarch population trend is not reversed. (

Just the other day I was visiting the Lady Bird Johnson Wildflower Center in Austin, Texas, when a man standing next to me said, “I need to go and buy some Milkweed (Asclepias spp.) The Monarch butterflies will soon be here in Texas.” Then this stranger went on and told me all about how the Monarchs will need Milkweed on which to lay their eggs. This made my heart sing! What if everyone had this same enthusiasm for planting Milkweed for the Monarchs!

Read more about my favorite native Milkweeds at


Spread the message with this “Plant Milkweed T-shirt by Butterfly Lady: