Dorothy Hoard is known for several books that she wrote about the out-of-doors of Los Alamos. She also began an annual summer butterfly count in 1993. It has continued annually ever since, well nearly.
A forest fire or summer thunderstorm occasionally has prevented a survey. (The following charts have gaps for some years as a result.) The surveys have been conducted at the Burnt Mesa, Valley Canyon and Camp May areas. The data therefore is for areas of increasing elevation. These areas change from the dryer and open countryside of Burnt Mesa to the forests and greater rainfall of Camp May.
It is remarkable that count of all species combined together varies so much from year to year, whichever of the three areas is considered. For example CHART 1 for Camp May shows 200 butterflies were counted in 1997 but only 1 butterfly was seen two years later 1999. CHART 2 for the Valle Canyon shows an increase from 5 butterflies in 2013 to 73 butterflies in 2015 as another example.
CHART 4 combines data for the three areas. The areas together indicate that these swings may be part of cycles that last for five or six years. For example the Camp May and Burnt Mesa areas increased from low counts in 2002 to high counts in 2005. They then returned to lows in 2006. The upward count is not as distinct for the Valle Canyon counts for these years. However it has similar low counts for 2002 and 2007. This multiyear cyclic pattern may reflect climatic conditions there were particularly favorable for butterflies from 2003 to 2005.
The life cycle of butterflies may provide an additional explanation for the multi-year pattern. Adult butteries typically live only a few days to a couple of weeks. A difference of a few days therefore may result in a survey happening before, during or after a peak in the number of butterflies in an area. The daily weather conditions also may have an impact. A survey may occur on a day when most butterflies are not flying due to cloudy or windy conditions.
What species of butterflies are likely to be seen during a survey? Chart 5 shows the four most commonly seen butterflies: (1) Checkered White, (2) Painted Lady, (3) Orange Sulphur, and the (4) Arctic Blue. The number seen from year to year varies considerably even if a species is among the most common for all the years combined. The chart shows that 70 to 80 members of a species may be seen in one year but then none are seen in other years. The four species are a part of the increasing/decreasing cycle for 2002 – 2007. They also are a part of a similar cycle for 1995 – 2000.
Interested in participating in the upcoming butterfly count? The 2016 annual count is being scheduled for July 23. An announcement with details will be given by PEEC at the Nature Center in coming weeks, (http://peecnature.org/events/).
Adult Checkered White butterfly. Photo by Marion Stelts
Checkered White caterpillar. Photo by Howell C. Curtis
Adult Painted Lady butterfly. Photo by Sally King/NPS
Painted Lady caterpillar. Photo by Sara G. Blow
Adult Orange Sulphur butterfly. Photo by Sally King/NPS
Orange Sulphur caterpillar. Courtesy photo
Adult Arctic Blue butterfly. Photo by Yvonne Keller