If you grew up in or before the 1950s or 1960s, butterflies were likely a common sight during the summer months, including monarchs, painted ladies, red admirals, swallowtails, blues, whites, sulphurs, and mourning cloaks. Many kids even had butterfly collections. That is not the case these days. Things have changed, and not in a good way.
A recent study published in the prestigious journal Science found that the abundance of butterflies had declined by 22% from 2000-2020. The research analyzed data from 12 million entries from 76,000 surveys on 2,500 locations spread over all regions of the United States. Although a few species actually increased, 13 times more species had declined.
It probably should not come as a surprise that butterfly populations are declining. Factors cited for causing the decline included the widespread use of insecticides, particularly neonicotinoids, habitat loss to agriculture, urbanization, and other land uses, and a changing climate.
Butterflies, like other animals, have their particular habitat and food requirements. The relationship between the monarch butterfly and milkweeds is well known. But have you ever given any thought as to what plant species are important to other butterfly species or what plants serve as food for the larvae? Prairie hilltops, for example, are an important habitat for the black swallowtail and members of the carrot family (e.g., wild parsley and meadow parsley) are the main source of food for their larvae.
So why be concerned about the decline in butterflies? They provide a variety of ecological services. They are important pollinators for native as other plants. They are also food items for a wide variety of other animals. Many birds for example eat the eggs, larvae, or adult butterflies. Some species influence nutrient cycling by feeding on decaying material, rotting fruits, and even dung. And the larvae or caterpillars generally feed on the leaves of certain plant species. And of course seeing butterflies helps make our days a little brighter.
So, make a point to take special notice of the butterflies you see this summer. There are around 150 different species in North Dakota, many of which are important components of many communities and provide us with important ecological services. Plus, they enrich our summer experiences. Hopefully measures can be taken to reverse their decline and help ensure that future generations can enjoy seeing butterflies dancing in the summer breeze.
