By BRUCE LUND
In doing field surveys with my high school insect class this month, we’ve watched an abundance of Monarch, Queen, and Painted Lady butterflies siphoning nectar from thistles, goldenrods, and other wildflowers.
Of course, many folks are delighted to have these butterfly royalty visiting flowers in their yards and gardens. And if the butterflies could speak, they would thank us for providing them with flowers that provide nectar. This is because at this time of year, just like geese and robins and many other birds, these butterflies are making their annual southern migration and flower nectar is a butterfly’s essential fuel.
The fabulous story of millions of Monarchs migrating to and from a few acres of fir tree forest in the Mexican mountains (for the main population) and the California coast (for smaller populations) is relatively well known from television programs and magazine stories.
But Queen migration has gotten little press. Their migration overlaps that of Monarchs as both flutter north in large numbers from Mexico, spread far into North America over the spring and summer, and retreat back to Mexico for the winter.
Queens especially funnel through Texas into Mexico, but WHERE they go is still a mystery. Do they congregate en masse in isolated sites still to be discovered like Monarchs? Here’s a terrific challenge for some dedicated Curious Naturalist to solve!
Monarchs and Queens have similar orange, black, and white wing patterns and utilize the same group of plants on which to lay their eggs and for their caterpillars to feed – the milkweeds. These are challenging plants to utilize since they have evolved toxins (called cardiac glycosides) that repel or poison most insects, birds, and mammals.
The Monarch and Queen caterpillars have essentially cornered the market on this food supply by having evolved special cells in which the poisonous glycosides are confined and accumulated. These cells make the caterpillars poisonous to predators and are maintained in the transition to the adult butterfly – making them poisonous too.
In looking at the variety of butterflies around us, my students and I often see cuts and bite marks in their wings from bird attempts to devour butterflies – which are generally a wonderful meal. However, while the wings of Monarchs and Queens often show lots of wear and tear from banging against vegetation, we don’t see many signs of bites. This is because birds have learned that chomping on these butterflies results in immediate and severe retching. Once experienced or observed, it is a lesson birds remember so well that they not only leave these butterflies alone, they refuse other perfectly edible species that have evolved similar coloration and wing markings such as the unrelated and edible Viceroy butterfly.
While Monarchs and Queens are larger and arguably showier, our most abundant migrating butterfly and the one most people are likely to see on their yard flowers is the Painted Lady. Indeed, my wife and I watched some feeding on Desert broom flowers at our house as I was writing this article.
Last Spring, I watched huge numbers of Painted Ladies migrating north, flying over I-15 and getting mashed on vehicle grills. The ones going south now are descendants of the survivors of that migration.
In proof reading this write up, my wife and chief editor added this comment with which I heartily agree: “How can something as fragile and delicate as a butterfly make, never mind survive, long migrations? It is truly amazing!”
Bruce Lund is a retired biologist and has a lifelong love of nature instilled by his grandparents and some remarkable teachers. He has lived with his wife, Flo, in Moapa since 1997.
