Butterfly Monitoring on San Bruno Mountain
When I tell my friends that I monitor butterflies, I think they picture me and the team skipping through a field in sundresses with butterfly nets in hand. We definitely do skip when we find a rare species! However, most of the time we hike up steep slopes trying to find our footing. Instead of butterfly nets we use iPads and binoculars to identify and record sightings. I usually wear Carhartt double-knee pants to keep the thistle at bay and a long sleeve shirt to keep the ticks from biting. While sundresses are one of my favorite outfits, they are not well suited for fieldwork.
Picture us more like this.
There are very few rules in ecology, but any experienced ecologist knows not to get separated from your lunch! This may sound trivial until what started as five- minute mapping hike becomes an hour or two distance from your starting point and your pack. Hunger pangs signal that you’ve made a grave mistake. We map violets to better understand the distribution of callippe silverspot, an endangered butterfly. The callippe rely on the host violets for laying eggs and larvae feeding. I was mapping violets to mark the perimeter of the violet patch when about half way down the slope I realized I had to go down, around and back up the slope to accurately map the patch. Let me tell you, my quick viola mapping turned into a two- hour hike down and up the slippery slopes of San Bruno Mountain chasing violets.
Fieldwork can be unpredictable. To monitor the San Bruno elfin populations we survey eight plots for elfin larvae that feed on stonecrop. Plots may be easily accessible from a trail in low grasses and take only 30 minutes to stake out. Yet, I have also trekked in and out through scrub and poison oak at shoulder height to map plots that require an hour in travel time, plus more time to stake out the plot. When I set out to do three plots in a day I’m never sure if I am setting myself up for a half field day or a 10-hour field day. That being said every day we go out we have to be prepared for a long day -- Because mama said fieldwork is like a box of chocolates, you never know what you are going to get.
San Bruno Mountain is a special park for conservation. It is the only place where the callippe silverspot, San Bruno elfin and mission blue are found together. Monitoring butterflies helps us understand how they are doing on the mountain, fluctuations in population from year to year are normal. The amount of butterflies can vary depending on host plant productivity, if there is less food there will lower survival rates. We monitor for dramatic drops in population that could jeopardize the species. The information gathered from fieldwork has helped stabilize many butterfly populations by reintroducing species to areas and addressing forces that can drive the population to decline such as invasive plants. Fieldwork is rigorous and rewarding. Yes, we work long hours and hike a ton! We also get to see some of the best views in the Bay Area and contribute to efforts that protect endangered butterflies. Getting to the top of the ridge and taking in my surroundings makes the hike worth every step. Even after a long day in the field I smile and reflect on how much was accomplished – I’m excited to get back out the next morning.
There is no better feeling than a sense of accomplishment, especially after a day of hard work. I am always proud of how far I’ve hiked and how many plots I surveyed, and I know that the days we go home dirtiest are they days that we worked hard and had the most fun!