By Jim Armbruster
Seasonal Environmental Educator
As the leaves begin to change color, the days grow shorter, and the temperatures get colder, monarchs are still on the move south. During a short break from the rain, on a nice sunny day, we at VINS tagged our last seven butterflies bringing our season total to 74 individuals. We may continue to see monarchs here throughout the end of October as they carry on their migration, but most will reach their wintering grounds by November.
Our tagging season started with our first butterfly on August 28th and ended with our last on October 9th. September 26th was a big day with 15 individuals tagged. All of our tagging data has been submitted to Monarch Watch, and while we endure another cold New England winter, we will wait to see if any of our butterflies write us from their tropical vacation in Mexico. (If one of our tagged butterflies is recovered while on their wintering grounds, we will be notified by Monarch Watch.)
According to Monarch Watch, this year’s numbers seem promising for a successful migration. Several roosts of butterflies have been observed on their path to Mexico with some roosts estimated to contain 1000 or more monarchs. During the migration of 2017/2018 there were 124 million monarchs estimated on the wintering grounds taking up 2.48 hectares of forests (24,800 square meters). But monarchs are not all doing well. Although these numbers seem huge, this is actually down 14.8% from last season. 20 years ago, monarchs covered 18 hectares and were estimated at 1 billion individuals. This year’s prediction is for monarchs to cover 5 hectares, with 6 hectares being considered the target for monarch recovery. Since this is our first season tagging butterflies at our Quechee Nature Center, it is hard to say how populations are faring here, but our initial numbers seem to show that our meadow is an important habitat for this species. Because of this we hope to expand our monitoring program in the coming years. This will include monitoring how well milkweed, a preferred plant for monarch eggs and caterpillars, is doing in our meadow. (This fall we have already spread milkweed seeds throughout the meadow in hopes to encourage more growth next spring.) It will also include monitoring butterflies for parasites throughout the summer, and of course tagging monarchs next fall.
There is still a lot that scientists don’t know about monarch migration. It is unclear what factors may lead to a big year of migration and what specific habitats are crucial to this species. Luckily, many of the citizen science projects that we at VINS participate in can be done in your own backyard. This means that we can all take part in helping to better understand and protect the magnificent winged creatures that are the Monarch butterflies. Monarchs are still emerging, even in the October chill.
To get involved with citizen science projects check out these organizations: