In a shocking (and awesome) announcement by the Monarch Joint Venture (MJV), eastern monarch populations are up 144% from last year!
If you recently read that monarch populations are down a devastating 86% this year and now you're hearing they are up 144%, don't worry, you aren't losing your mind. If you are unfamiliar with North America's monarch butterfly populations, it's important to note that there are two separate migrating populations in the United States and one mostly nonmigratory population in Florida.
The two distinct migrating populations include one in the far west (west of the Rocky Mountains), and one in the east (east of the Rocky Mountains).
We'll start with the bad news first...
Western Population: This is the population that has declined 86% this year, which couldn't be worse news for an already struggling population.
(Read Naturedigger's earlier blog posts to find out how you can help)
Where do they migrate to and from? The western population overwinters along the coast of California and migrates in early spring to the Rocky mountains, then returns to the California coast in the fall. See the migration map below provided by Monarch Watch.
Now for the good news...
Eastern Population: This is the population that is rebounding (at least this season) and appear regularly in the news due to their dramatic decline over the last 20 years.
Where do they migrate to and from? The eastern population overwinters in Mexico, specifically in the in the oyamel fir forest, which is how the population numbers for the year are determined. In the spring they migrate north from Mexico and fly throughout the United states east of the Rocky Mountains, north toward Canada and east throughout the eastern United States. The last generation then returns back to their wintering grounds in Mexico in the fall. This epic migration is as mysterious as it is truly remarkable.
See the map below provided by Monarch Watch and the chart of population by hectare in Mexico provided by the Monarch Joint Venture.
So what can we attribute this unbelievable increase in eastern monarch populations to? According to the MJV, "Good weather conditions during the breeding season supported the increase, as well as efforts across North America to protect and restore habitats."
The weather is something we obviously have no control over, however, participation in habitat restoration we can all control. Clearly the formula the MJV (and its many partners) is using is working.
Now let's get to work on the western population and see if we can bring those numbers up next year, as well.
Check out the MJV's website links for general information about monarch nectar plants and much more as well as specific information about the eastern migratory population. Visit the Xerces Society for guidance on the western monarch population as well as pollinator plants for your area if you live in the western US.