2011: Monarch Update

An update from Nan:

Last year I wrote an article about Monarch butterflies and how Mark and I do what we can each year to encourage them to visit our backyard garden. We plant several different types of Asclepias, the host plant for the Monarch, and we then bring the caterpillars indoors to increase their chances of survival. We then release the adult butterflies for the cycle to begin again. Eventually, in mid-September, the newly eclosed adults leave us and migrate to Mexico. This year we released more than 75 adult Monarch butterflies. This is about 40% fewer than we released in 2010.

We’ve been doing this for 4 or 5 years now and we learn new things every year. I think the most important thing that we learned this year is how important the state of Texas is to the Monarch migration. When spring arrives each year, the butterflies overwintering in Mexico take flight, take in nourishment and most begin to immediately mate. This allows them to deposit eggs on the milkweed that is found along the HUNDREDS of miles they will cross in their northern migration through Texas. These are butterflies that have been overwintering for months. They are the same butterflies that traveled up to 2500 miles in order to reach Mexico. They have not eaten in months. Instead, they are living off the fat they have stored from last fall during their journey south. (The generation of Monarchs that make the journey south and begin the return trip live up to five months, while all other generations of Monarchs that populate our gardens in summer live only two to six weeks.) And so, their one mission is to mate, begin the journey north and LAY EGGS! The vast majority of these butterflies will lay eggs in Texas and soon die. Mission accomplished.

Now, imagine that Texas is suffering from a drought. And temperatures are WELL above normal. The milkweed is suffering from the dry conditions and the butterflies cannot stand the extreme temperatures. Some of the migrating Monarchs will die before they are able to find suitable amounts of milkweed. Those that survive decide to move farther north to find better conditions, only to find those areas north are still too cool and/or rainy for the Monarchs or the milkweed. That is exactly what happened this past spring and so the experts watching the migration had low expectations for a ‘good’ Monarch year. Despite that, as I said earlier, I thought we had a decent turnout in our own little corner of Monarch country.

The story doesn’t end there though. When September came around, Texas was still experiencing drought along with very high temperatures. Monarchs ‘bulk up’ during their migration south and again, Texas takes up hundreds of miles of that migration. Important miles. This year, because of its hot, dry summer, it did not have as much nectar to offer the butterflies.

Now, all we can do is wait and see how they fare on the mountaintops in central Mexico – and hope for a perfect Spring. Especially in Texas. We can do our part by planting milkweed for them before they arrive here starting in late June. I know Mark and I will be waiting for them with anticipation….and plenty of milkweed!

Author: Mark Plunkett

I am an Ohio master gardener volunteer living in Cincinnati, OH. My wife, Nan (also a master gardener), and I strive to be faithful stewards of 'our' property and contribute to the biodiversity of our community. We are both members of the local chapter of Wild Ones and volunteer horticulture team members at the Cincinnati Zoo & Botanical Garden where we work in the native plant program, pollinator gardens and monitoring bird trails. In my spare time, I like to read about the natural world and the history of science

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