Monarch numbers reason for worry
It is not really news that Monarch butterflies are in trouble. Their numbers have been dropping steadily for the last 20 or more years. Last week, the International Union for the Conservation of Nature put the Monarch on their red list of species that are endangered. This holds no legal protections or incentives to help the Monarch, but it shows that scientists are justifiably worried.
Older people often say that there were a lot more Monarchs when they were kids. It is easy to say, but harder to prove. It is very hard to count the population of a butterfly that migrates to fill a continent. The main way to count them is to calculate how much space the butterflies take up when they go to Mexico.
The good news is that Monarch populations are up 35% from last year. The bad news is that a 35% increase of a low number is still a low number. On average, the butterflies cover two hectares less over the last ten years compared to the previous ten years. A hectare is close to two and a half acres. Think of it as 2 and a half football fields. There are five football fields fewer Monarchs now than when I started raising them.
To imagine what a loss of five football fields of Monarchs on their wintering grounds looks like is hard. First, cover five football fields with a forest, then cover every tree with so many butterflies that it looks like the trees have a living carpet of Monarchs across each branch. Each football field sized forest would house millions of butterflies.
All the Monarchs east of the Rocky Mountains empties into a forest in the Mexican Mountains. The population was up 35% last year, but still only covered about seven acres of land. The International Union for the Conservation of Nature puts the loss at 72% over the last 10 years.
Many people see this loss as a call to action. What can we do to save the Monarch? This has taken many forms over the years. I started raising Monarch butterflies seventeen years ago to release them at my wedding. The Monarchs spent a day at Audubon before that in what was the first Monarch Butterfly Festival.
The Monarch population dropped from covering eleven hectares the year I was married to covering two hectares the following year. People then worried they would disappear forever. I responded like many people did: I began to raise and release Monarchs that I found as eggs. Over 80% of the Monarch eggs laid do not become adults, so grabbing some and raising them should boost the population. Unfortunately, there is no evidence that raising Monarchs raises the population that migrates to Mexico. There is some evidence that captive-bred Monarchs are weaker and more disease-ridden than their wild counterparts. Raising Monarchs is a great learning opportunity and a marvelous experience, but may not help the population at all.
One thing that people can do is plant milkweed. Milkweed is the only plant that Monarchs lay their eggs on and the only food the caterpillar will eat. Butterfly gardeners call this a host plant. This plant was once more common in the area, where it grew in vacant lots and old fields. As suburbs and homes spread through some old fields, and others grew up into forests, the amount of milkweed has gone down. Plant milkweed in your yard for Monarchs to lay eggs on.
The other issue is nectar plants. Monarch butterflies exclusively eat nectar from flowers, which makes them a nectarivore. They need flowers that they can eat from in the area, but also all through their fall migration to Mexico. Many Monarchs fatten up on the vast local fields of goldenrod in the fall, but I have seen migrating Monarchs in my yard all the way into October. The Xerces Society, which is dedicated to insects, has a list of plants that Monarchs love to eat on, including goldenrod, New England Aster, Butterflyweed, and Purple Coneflower. It must be hard to be an insect and fly over a thousand miles while searching for food, so planting some migration rest stops makes sense. Audubon has a Monarch Waystation filled with plants for Monarchs to lay eggs on and nectar plants to feed the adults.
Our yards are what we can control. We can plant milkweed and nectar plants for the Monarchs to make our tiny corner of the world a better habitat for them. It’s even better if we can get milkweed and flowers planted in the median strips of highways or in vacant lots to expand that needed habitat.
Monarchs problems are bigger than what we can control in our yard. Texas is having a drought this year, which is increasingly the case. Monarchs have to pass through this drought zone on their way to Mexico. Many Monarchs die there when the natural nectar sources dry up and die in the drought.
The Oyamel Fir forests where Monarchs spend the winter in the Mexican Mountains are also under threat. These stands are surrounded by illegal logging activity and subsistence farming that open up the stands of trees where the Monarchs spend the winter. This makes them more vulnerable to cold weather and may cause huge numbers of Monarch deaths in a cold year.
Herbicides and pesticide use in yard and farming kills many caterpillars and butterflies as well. Sometimes people don’t think about the butterflies and caterpillars they are trying to attract to their yard as they spray chemicals to eliminate the pests they want to leave the yard. Many butterflies accidentally die this way.
I think the best thing you can do is take positive action on the things you can control to help the Monarch. Plant milkweed. Plant nectar plants. Inspire wonder in friends, family and children by raising a caterpillar or two to inspire them to create some Monarch habitat in their yard. Every little bit helps. If we all do a little, and people all across the country do a little, maybe we can solve a continent-wide problem one yard at a time.
Audubon Community Nature Center builds and nurtures connections between people and nature. ACNC is located just east of Route 62 between Warren and Jamestown. Audubon has a Monarch Butterfly Festival on August 27 and Butterflies and Brews on August 26 for adults for those who want to learn more about Monarchs. The trails are open from dawn to dusk as is Liberty, the Bald Eagle. The Nature Center is open from 10 a.m. until 4:30 p.m. daily except Sunday when it opens at 1 p.m. More information is online at auduboncnc.org or at (716) 569-2345.