The Value of Rare Species or Why you should care about a butter-moth

My master’s graduate project focused on characterizing the habitat of the Dakota skipper butterfly, which was put on the federally threatened species list last October. The butterfly originally occurred from Illinois to Canada in the prairie of The Great Plains. As its habitat disappeared so did the butterfly. Now it is restricted to isolated populations occurring in South Dakota, Minnesota, North Dakota, Manitoba and Saskatchewan.

People that are not in the conservation world often ask me why conserving rare species is important. They want to know why time and energy is spent on studying and preserving one species that obviously isn’t at the top of the survival of the fittest list. The Dakota skipper’s appearance doesn’t help its cause either. It is a dark brown and orange moth-like butterfly that doesn’t necessarily capture the hearts of those that look at it.

This question of “Why should I care about the Dakota skipper?” translates in my head to “How does the Dakota skipper affect me?” The simple answer is that it doesn’t affect you. At least, it doesn’t affect human individuals directly. The Dakota skipper does not provide food, shelter or security. However, although these direct effects may be the most obvious, they are not the only effects that should be taken into account.

The more complicated answer starts with acknowledging that the Dakota skipper is a small part of the larger prairie ecosystem, and the prairie ecosystem is part of a larger social-ecological system, which contains both humans and wild systems. Scientists have confirmed what is intuitive for most people, that human well-being is inextricably tied to the services provided to us by natural systems. These services include the pollination of agricultural crops, regulation of the climate, control of agriculture pests and diseases and water filtration by wetlands. Social-ecological systems are large and complex, but scientists have figured out that biodiversity or the number and distribution of species, maintains and supports ecosystem processes, which in turn provide these important ecosystem services.

So by itself the Dakota skipper may not seem important, but let’s put it back into the context of its system. One way to do that is to look at the reasons why the species is on the decline. One of the limiting factors for the Dakota skipper is that it requires high quality native prairie to survive. Currently, high quality prairie exists in small remnants, scattered across a landscape made up of crop fields and low quality grasslands that have been degraded by invasive species and poor management techniques.

The distance between high quality prairie remnants is especially a problem for the Dakota skipper. The Dakota skipper has a wingspan of only one inch and is in the butterfly life-stage for three weeks out of its lifetime. So, the Dakota skipper has low mobility and cannot travel very far. If a remnant is not managed properly, the population can collapse. Once a population has collapsed, the re-colonization of skippers from a different remnant is highly unlikely so followed to the logical conclusion, isolated remnants of Dakota skipper populations will extinguish one by one until none are left.

The Dakota skipper may not seem important by itself, but it is an indicator of the status of prairie habitat. Its decline indicates that there is not much high quality prairie remaining, and what is left is so fragmented that its functionality as habitat is decreasing. It’s not only the Dakota skipper that is paying the penalty for this. Declines in the populations of prairie butterflies, native bees and grassland birds have been observed for years. Most famously, South Dakota saw a 64% decline in the pheasant population from 2012 to 2013. This negatively affected the state economy, which is dependent upon revenues from hunters that flock to the state each pheasant season. This more direct effect motivated policy makers and land owners to start a conversation about habitat and conservation within the state.

We have to be careful not to limit the conversation to only the “useful” species. These species are part of a larger system that we have to acknowledge and maintain. A decline in pheasants is one of the many declines in resources that could occur. In the Great Plains, we already see the eutrophication of lakes and rivers from the addition of nitrogen and phosphorous in the system. We are seeing the extreme climate events from global climate change including droughts, floods and major storms that negatively affect crop yields and rural communities.

We study rare species to learn more about the systems that they live in. We study them to check in on how those systems are functioning. Hopefully, through understanding will come preservation of the Dakota skipper and its system and the resources and services provided to us by that system. The act of studying rare species is not only about preserving the Dakota skipper, but also about preserving ourselves and future generations.