Butterflies of Pinnacles National Monument
Photo by Paul G. Johnson II
Butterflies are a wonderful reflection of the surrounding landscape. On a well-manicured lawn they are scarce. In a vacant lot where plants are more diverse but nature has been severely disturbed, you may find a few more. In a butterfly garden where the gardener has taken care to choose a variety of plants that will satisfy the needs of thirsty butterflies as well as hungry caterpillars, the diversity of butterflies often reflects that care. But the best places to see lots of butterflies of many different kinds are places where people have taken care to leave nature well enough alone.
Pinnacles National Park is just such a place. Although it is only about five miles wide and seven miles long, most of the land is undisturbed wilderness that supports a great diversity of living things. How many different kinds of butterflies would you guess are found here?
Sixty-nine different species of butterflies have been recorded at Pinnacles. About 35 species are common enough that you are likely to see them if you visit the right habitat at the right time. About a dozen are so abundant that you may see hundreds of them on a visit. But how do you know the right time and place to find them?
The Pinnacles National Monument Butterfly Checklist shows the number of butterflies of each species you can expect to see in a few hours for each month of the year and in five different habitats. Once you know the right time and place to look for butterflies, you can get even more specific by also looking for their host plants (the plants on which butterflies lay eggs and caterpillars feed) and nectar plants (the favorite flowers from which adult butterflies drink nectar).
For example, let's say you are visiting Pinnacles in July and you want to see a Sylvan Hairstreak. The Checklist says that in riparian (streamside) habitat in July you can expect to see more than 20, and that their host plant is willow and their favorite nectar plant is milkweed. Since willows don't grow in all riparian habitats, on the advice of a Park Ranger you take the Old Pinnacles Trail. Along the trail you notice three different species of willow. On two of the species you find nothing. But as you approach the shrubby, smooth-leaved species, you see several small gray butterflies zip off from the tips of the leaves and then return. As you continue, you scare up several Sylvan Hairstreaks from each of these willows that you pass. Then you spot a milkweed with half a dozen Sylvan Hairstreaks sipping nectar from its flowers. Mission accomplished, you've had a fine hike and no doubt seen many other butterflies along the way.
Here are some tips to keep in mind when seeking butterflies. Butterflies are creatures of the sun. They are most active from 9 a.m. to 4 p.m., and are seldom out in the cold, rain, or wind. Some good butterfly spots include hilltops, moist areas, open patches of ground, and flowers. Certain species of flowers attract many more butterflies than others. In the summer and fall the few flowers in bloom will often draw butterflies from great distances. Some particularly good butterfly flowers at Pinnacles include wallflower, California buckeye, thistles, California buckwheat, wooly yerba santa, summer mustard, milkweeds, vinegar weed, exotic mints, shrubby butterweed, coyote brush, and heliotrope.
What does Pinnacles National Park do to ensure that butterflies will be here for all to enjoy for many generations to come? The number one threat to butterflies everywhere is loss of habitat. A decline in a particular butterfly species is often a direct reflection of a decline in habitat for its host plant. By protecting natural processes and habitats across the wilderness landscape, Pinnacles goes a long way toward protecting butterflies. (One part of that protection is to prohibit collecting butterflies, wildflowers, or anything else within the Park.)
But how can we be sure we are doing enough? In order to keep track of how butterflies are doing over the long term, we conduct an annual Pinnacles National Monument Butterfly Count. The information from this count can be compared to data from previous years to help us detect species declines. We can also look at other places that conduct similar counts to see whether the declines are widespread or restricted only to Pinnacles. We can then look for causes and begin to remedy them.
Ultimately, our goal is to ensure that visitors to Pinnacles National Park have the same opportunity to see Sylvan Hairstreaks and other butterflies regardless of whether it's the year 2004 or 4002. If you would like to help us achieve this goal, please report any unusual butterfly sightings, and join us for the annual Butterfly Count.