Every February 5th, we celebrate our western population of monarch butterflies. They have a day set aside just for them, as it should be. What does western population of monarchs actually mean? Settle in for a quick lesson on monarch populations, migration and their status in North America.
There are three separate populations of monarch butterflies (all the same species):
First, there is the eastern population that is well-known for their epic migration from Mexico in the spring up through central and eastern United States and into Canada. After laying eggs across the country (up to five generations), the last generation (that has never been to Mexico) makes that incredible migration south to the oyamel fir forests in central Mexico. How they manage this, is still a mystery, but hopefully we'll find in the near future exactly how they accomplish this incredible journey. Unfortunately, overwintering sites in Mexico that support the eastern population has declined up to 95% since the 1990s, so this population is in big trouble. Not only is their migration threatened, but also their overwintering grounds in Mexico. A double threat. The final population numbers are not yet available for this year, but hopefully they will be up and eastern monarchs will begin to recover. Visit the Monarch Joint Venture website to read more about the eastern population decline and how you can help.
Second, there is the mostly non-migratory population in south Florida that sticks around all year. There isn't enough data to say for sure if they are 100% non-migratory, tagging data may indicate otherwise, but from what we know, they hang out in Florida all year.
Finally, there is the western population of monarchs. This population migrates from overwintering sites along the California coast in spring east to the Rocky Mountains. Again, several generations later, the last generation migrates in the fall back to the coast. Now for the bad news. The western monarch population is also in trouble. Big trouble. It would be nice to celebrate, uninhibited, our beloved orange and black butterfly, but we just can’t. Instead, we need to reflect on their critically low numbers (down 86% since the 2018 count) and figure out ways to help them. This is one of those, we made this mess, now let's clean it up scenarios.
Due to several factors, including habitat loss, pesticide use, loss of overwintering sites, climate change, and others (all created or exacerbated by humans), we are now faced with losing one of our most iconic insects. Last year, Xerces Society for Invertebrate Conservation (Xerces), reported for the second year, historically low numbers of overwintering monarchs along the California coast. This data prompted a second call to action for western monarchs. This is really bad news. However, rather than stew and feel helpless, let's look ahead...
It's 2020, a new year, with new possibilities and a brighter outlook all around, so let's see if the collective "we" can help this species rather than watch it go extinct like so many other species we've said goodbye to in recent years.
Here's what we can all do:
First, plant milkweed. That's a big one. Just visit the Xerces seed finder website to locate seed vendors in your state or visit your local nursery and request native milkweeds.
Second, plant native flowers that are available to migrating monarchs in early spring and late fall. They need these vital food sources when they leave their overwintering sites and when they return to them.
Third, stop using chemicals such as round-up on your weeds. This kills many plants in its path and is terrible for not only monarchs, but other pollinators as well.
Fourth, protect overwintering sites in California. Without these sites, monarchs can't make it through the winter and therefore, cannot migrate in the spring.
Last, get involved! If you're a California resident, you can help Xerces by counting overwintering monarchs along the California coast. Just download the Monarch SOS app and go to Report, then select Xerces Western Monarch Count. You can also participate in the Western Monarch Milkweed Mapper which allows you to report monarchs and milkweed throughout the year.
If we all do our part and help our western monarch populations, next year, there will hopefully be cause for celebration.
On a very sad note: Our hearts go out to the families of the slain monarch conservationists from Mexico, Homero Gomez Gonzalez, manager of the El Rosario butterfly sanctuary, and Raul Hernandez Romero, a tour guide at the sanctuary. Both were champions for monarchs and will be terribly missed by the entire monarch community as well as the monarchs that will undoubtedly suffer in their absence. May these fine men rest in peace and those responsible for these unspeakable acts be brought to justice.