On Thursday, January 25, Rich Bray and Stephanie Mason presented an update about their ongoing efforts to catalog the butterfly species of Rocky Mountain National Park in Colorado. Rich started the project in 1995, originally envisioning a 5-year study. The monitoring project has steadily gained both respect from the scientific community and help from interested volunteers. The monitoring season, generally lasting 20 weeks, runs from May 1 to around September 15. Predetermined routes are carefully surveyed once a week, and all butterfly species seen on these routes are recorded, along with relevant information such as weather conditions.

While setting up the project, Rich uncovered some fascinating and useful information regarding individuals who have surveyed the park's butterfly species in the past. A list compiled in 1931 by Grace and John Sperry (an entomologist with the American Museum of Natural History in New York) helped Rich and Stephanie add certain species to their master list. Dr. Weist, the first mayor of Estes Park, also studied butterflies in and around the park in the 1930s, but he was not specific enough about the locations of his sightings; the surveyors were unable to determine which butterflies had been spotted inside the park's borders. However, the careful notes of Phillip Ritterbush, a summer ranger in the park in the 1950s who kept notes on butterfly occurrences, were useful and allowed the surveyors to discover the location of a small colony of Ridings' Satyr (Neominois ridingsii). Within the park, Neominois ridingsii flies only in late August, supporting the theory that the fall brood may actually be a separate species. The oldest known checklist of Colorado butterflies was recorded in 1866 by Reakirt of the Entomological Society of Philadelphia (now The American Entomological Society). This document provided an especially interesting glimpse into the natural history of butterfly species still found in the park today.

The surveyors have encountered a few difficulties during the past five years: for instance, in the Rockies, skies are often cloudy, and butterflies there stop flying the moment clouds obscure the sun (possibly to conserve precious heat in the cool of the high altitudes). Another threat facing much of the park's flora and fauna is a serious overpopulation of elk, which overgraze the meadows and threaten the diversity of plants available for the butterflies to use. Rich and Stephanie also discovered that, while having predetermined routes is important for consistency in the survey, walking those same routes day after day and year after year can actually get boring! Fortunately, it's a gorgeous area, and there is always a little free time to explore other areas of the park and observe different aspects of butterfly behavior.

Last season's research associate, college student Lauren Agusta, performed a butterfly pollination experiment for her senior research project. Rich and Stephanie also became interested in researching this surprisingly neglected subject. Most pollination studies have been performed in Europe (particularly Sweden). While most of us take for granted that butterflies are pollinators, there has been some scientific debate about how significant butterflies are as pollinators, and whether they are the main pollinators for any plant species. Because bees and flies are known to be important pollinators, one theory proposes that bees and flies are the main pollinators of most plants, while butterflies are nectar visitors who may incidentally pick up pollen but are not efficient at delivering it.

Rich showed a fascinating slide, taken in West Virginia by Jim Davidson, of a butterfly visiting a Yellow Fringed orchid (Platanthera ciliaris). Orchid pollen is contained in a sticky mass called a pollinaria. In this slide, the pollinaria is clearly visible on the butterfly's palps, demonstrating that they are capable of transferring pollen.

On the other hand, Stephanie and Rich also observed some non-pollinating ("parasitic") butterfly behavior. Two butterfly species were seen repeatedly visiting legumes, a plant family with tightly closed flowers that scientists have always assumed butterflies are not strong enough to push open. Instead, these butterflies used a gap on the side of the flowers to reach the nectar, bypassing the pollen transfer mechanism and essentially earning a free meal.

For her pollination experiment, Lauren Agusta chose to use the Field Scabiosa (Knautia arvensis), a non-native (but not invasive) plant which is attractive to many butterfly species and has been used in several of the European pollination studies. She wrapped loose netting around a number of Field Scabiosa flowers while they were still in bud; this was to ensure that no insects could pollinate the flowers except for the test subjects. After catching butterflies and refrigerating them for a time to slow and starve them, Sara placed a cage over the netted flowers, removed the netting from the "virgin" flowers, and placed the butterflies inside the cage. After the butterflies had nectared on the test flowers, the flowers were netted again; if they set seed, it would demonstrate that the butterflies had succeeded in pollinating them. Unfortunately, there were a number of weaknesses in this study: for instance, some butterflies immediately flew to the top of the cage and didn't nectar, and some flowerheads were netted too tightly, allowing smaller insects to pollinate the test flowers through the netting. Nevertheless, Stephanie and Rich are interested in continuing the study and learning from the difficulties encountered by Lauren.

In addition to their species surveying, Rich and Stephanie have also made observations on how butterflies behave while visiting certain flowers. In many instances, what they saw contradicted earlier studies and assumptions. A previous paper studying bees and butterflies concluded that bees tend to spend a long time at individual flowers and stay in close proximity to their hive, while butterflies take a "hit-and-run" approach, traveling greater distances and never alighting on a single flower for a prolonged time. Rich and Stephanie did not find this to be the case, as butterflies were repeatedly observed landing on flowers with many tiny florets per flowerhead (like composites) and staying for long periods, carefully drinking from each flower. Additionally, they found that butterflies do not visit only the flowers that they appear best suited for in terms of size or shape; the Anise Swallowtail (Papilio zelicaon), for example, is a large butterfly which was frequently seen visiting very small phlox flowers.

Also noted were some strong butterfly/plant associations. The Sonora skipper (Polites sonora), for example, seemed to prefer nectaring from the Colorado thistle (Cirsium coloradense), and the Sheridan's hairstreak (Callophrys sheridani) and Easter daisy (Townsendia exscapa) also share a strong relationship. While this may be partly explained by the early emergence of C. sheridani and equally early blooming date of T. exscapa, the scarcity of other pollinators flying that early in the season makes it seem likely that the Sheridan's could be a major pollinator of Easter daisies.

As the butterfly monitoring project heads into its sixth season, increased volunteer support has transformed the effort into an open-ended project with no definite ending date. Rich and Stephanie plan to eventually archive the data they collect on several websites where it may be easily accessed; to help them reach this goal, several volunteers created a relational database program which helps plot the data and extrapolate useful results. Some information is already available on the Butterflies of Rocky Mountain National Park web site.

There is much still to be learned about butterflies and their behavior, and Rocky Mountain National Park, with 265,000 acres, offers a wealth of opportunities for research in highly varied habitats, not to mention incredible scenery and beautiful fields of wildflowers. If you are interested in volunteering to assist with the butterfly survey, please contact Rich Bray at mtlep@earthlink.net or Stephanie Mason at smason@audubonnauturalist.org

This summary transcribed from the Webmaster's personal notes and a telephone conversation with Rich Bray.