While you are undoubtedly familiar with the monarchs’ fall migration, here are 10 interesting monarch migration facts you might not know:
1. The Monarchs aren’t going the way of the Dinosaur anytime soon, but…
There is reason to be concerned about the future of the monarch migration as we know it. This chart by Monarch Watch is a sobering look at the alarming decline of what was once a booming migration:
2. The Monarch Population Estimate is Only…an ESTIMATE⁉️ 😲
Over the past decade, too many of us (myself included) have been fixated on the overwintering estimates coming from Mexico.
Based on sighting reports after the monarchs’ departure each season, these winter numbers have (at times) seemed wildly inaccurate, which has led me to consider these follow-up questions:
Was the population concentrated in an area that wasn’t covered during the snap-shot count? Are there additional winter butterfly populations located between the southern US and central Mexico? Is there political motivation (endangered species list inclusion) for underreporting? How accurate are current counting methods?
You might have noticed on the population graphic above, that they don’t list a population estimate of the actual number of monarchs …just the number of hectares that the population occupied. (2.10 hectares = 5.24 acres).
Keep doing what you’re doing, and let’s challenge the science community to figure out a more accurate method for measuring the true state of the butterfly population.
3. Fall Blooming Plants can Attract Hundreds of Migrators!
Some luck is involved in enticing mass monarchs through your garden gates, but by planting flowers like Mist flowers, Liatris ligulistylis, and the Mexican sunflowers in the following butterfly video, living this dream is a distinct possibility…
4. Monarchs Roost on Trees in Clusters that can Number in the Thousands
This culminates in the roost to end all roosts at their Mexican wintering grounds where they number in the millions. Coastal California also has overwintering roost sites in the thousands. The trees are literally covered in a blanket of monarchs.
Back in the northern US, monarchs also form nightly roosts as they make their way down to Mexico. This one was formed in our Minnesota garden:
However, there is not always safety in numbers, as the following article and video reveals one of the greatest threat to the monarch migration and other endangered wildlife…us. 😢
5. Some of the Western Monarchs DO Migrate to Mexico
It was reported at the Monarch Biology and Conservation Meeting (2012) that butterflies tagged out west have been found on the forest floors of the Mexican wintering grounds.
6. Monarch Butterflies Glide in Upper Air Masses called Thermals to Conserve Energy
They ride these thermal waves all the way to Mexico. They fly at speeds ranging between 15-25 mph…one tagged butterfly was recently reported on Journey North to have traveled 265 miles in one day.
Recent flight study results posted on journey north revealed that a monarch with 140mg of fat to burn could fly for 44 hours when flapping, but 1,060 hours when soaring and gliding!
7. Monarchs Mysteriously Arrive at the same Remote Wintering Grounds Season after Season
Strangely, none of the returning monarchs have ever been to the wintering grounds before. If there are maps from ancestors in their genetic coding, imagine what this could mean for your monarch butterfly garden at home. Once they find you…
8. The Mexican Forest is NOT a Safe Haven!
It’s estimated that more than 15% of the overwintering population will fall victim to predators that pluck them like berries from trees. These predators include black-backed orioles, black-headed grosbeaks, and black-eared mice. See how these predators are a danger to monarchs in two ways:
9. The Monarchs that Migrate to Mexico in Autumn are the Same Ones Returning to Lay the Foundation in Spring
These mature ladies will mate in Mexico (in late winter) before seeking fresh milkweed in the southern US to start a new spring season filled with the magic of monarchs.
10. Migration Monarchs are Massive
While the wingspan of earlier monarch generations is generally 3.5-4″, most of the migrators have wingspans over 4″…no doubt they’ll need the super-sized wings for the long journey ahead…
Did you know these 10 monarch migration facts? For more info on migrating monarchs and how you can help them get off to a good start at home, sign up for Raise The Migration here