A SLIVER OF CREATION
After I started my job at North Carolina State University in summer 2001, I toured the habitats of two of the last known populations of the St. Francis’ Satyr (Neonympha mitchellii francisci), located at Fort Bragg army installation in southern North Carolina. I traveled through pinewoods on rutted dirt roads to visit a just-discovered population where the butterfly was easy to spot. This marked the beginning of my research on the St. Francis’ Satyr. I had some early successes and found a few new populations. This inspired me to continue my search for undiscovered populations in remote wetlands at Fort Bragg. Every summer since, I have trudged through swamps and broken through walls of shrubs and vines. For the most part, my effort has been in vain. My challenges in finding new populations of St. Francis’ Satyr were emblematic of the science and the search for the rarest butterfly that lay before me.
The butterflies that are the subject of this book represent just a sliver of creation. If we were at a dinner party and I asked you to think of a rare animal, what would come to mind? I would expect to hear names of animals such as the Giant Panda (Ailuropoda melanoleuca), the Black Rhinoceros (Diceros bicornis), or the Northern Spotted Owl (Strix occidentalis caurina). Like the butterflies I study, these animals are rare and threatened. Unlike the rarest butterflies, they are large, charismatic vertebrates. These animals are also different in a way that may not be immediately apparent (at least it was not to me): they are not nearly as rare as the rarest butterfly.
Rare butterflies make up a small number of earth’s nineteen thousand or so butterfly species, and butterflies in general make up a small fraction of the estimated 5.5 million insect species. Relative to other insects, butterflies hold an advantage: they provide us clearer avenues for understanding general threats to biodiversity and pathways to conservation. We know much more about butterflies – their diversity, ecology, and evolution – than any other group of insect. We also know more about the size of their populations and about the area of their ranges – which means there are data to support my assessment of rarity.
Imagine the increasingly likely scenario in which you could corral all the living adults of all the very rarest butterflies and then hold them in your hands. If, for example, you could hold the entire world population of adult Schaus’ Swallowtail (Heraclides aristodemus ponceanus) butterflies, its weight would be roughly six ounces. The collective weight of all individuals of the five rarest butterflies that I discuss in this book would weigh only three pounds five ounces – as much as one panda’s paw. And, in contrast to these tiny populations, there are billons of individuals of such common butterflies as Painted Ladies (Vanessa cardui) and Small Cabbage Whites (Pieris rapae).
The rarest butterflies have not always been rare. Some were very abundant until the last few decades; it is likely that their numbers dropped from millions to thousands. For other rare butterflies, it is impossible to estimate their historical abundance. However, we do know the historic range of their habitats and from that we can extrapolate high abundances. Global habitat loss and climate change have relegated each species to minuscule land parcels, areas as small as a single golf course or even a football field. I have found rare butterflies in unexpected places, their populations restricted to artillery ranges or beaches or backyards.
