Urbanization and corridors can work together to conserve a rare butterfly species

The crystal skipper (Atrytonopsis quinteri) is a species of butterfly not known for its size (average for butterflies) or its coloration (brown with a few white speckles on its wings). Indeed, if the average beach-goer were to see it while traipsing around in the skipper’s natural dune habitat, they would likely pass it off as “just another butterfly”.

However, the crystal skipper is far removed from the average butterfly. A study conducted in 2015 identified it as endemic to just a 50 km stretch of beach in North Carolina nicknamed the Crystal Coast.  Its total range is less than 3,300 ha of dunes sandwiched between the ocean and housing developments. Further, it is a prime example of a species experiencing habitat fragmentation due to urban development.

The most critical component of the crystal skipper’s habitat is its larval host plant, seaside little bluestem. This native grass grows along a thin band of vegetated dunes along the beach.  However, this band is divided and degraded when beachfront property is developed, which leads to habitat fragmentation. A study in 2010 found that 43 kms of the total 50 km range is home to the smallest of three isolated populations, and these 43 kms are the most fragmented.  A recent pilot study determined that areas adjacent to developed land possess the lowest percent cover and highest patchiness of seaside little bluestem.

Fortunately, these butterflies are not so easily deterred: a study in 2011 found that crystal skippers are able to disperse through urban areas, as long as there are at least a few small patches of seaside little bluestem around. Since the crystal skipper can tolerate and even utilize urbanized areas, its conservation is an example of how urbanization and corridor creation can work together. Since large, connected corridors are not feasible in the region, patches of seaside little bluestem that act as “stepping stones” are a valuable alternative strategy. For the crystal skipper, stepping stones can be highly intermixed with urban areas and still be useful.

Crystal skipper planting 2018Habitat restoration takes center stage in the effort to create stepping stone habitats for crystal skippers. The process begins with an assessment of standalone plot habitat quality, followed by site restoration; for the crystal skipper, this means detailed vegetation surveys and planting of seaside little bluestem. This work is combined with other critical efforts such as educating the local community, distributing seaside little bluestem to beachfront property owners, and encouraging local land and business owners to get involved in crystal skipper habitat restoration. This community-driven restoration focuses on planting local yards with seaside little bluestem and other food sources such as morning glory and yellow thistle, therefore increasing the prevalence and connectivity of the crystal skipper’s habitat.

The crystal skipper is an exciting example of a rare, endemic species that can tolerate urban development. Crystal skipper conservation has the opportunity to work around urbanization in corridor creation; indeed, enabling urban areas to function as corridors by maintaining valuable stepping stones. The caveat is that conservationists and scientists must diligently spread awareness of the crystal skipper’s habitat needs, and the local community must be willing to do things just a little differently (ex. planting native grasses instead of exotic ones) for “their” butterfly when developing beachfront property.

Resources

Burns, J. 2015. Speciation in an insular sand dune habitat: Atrytonopsis (Hesperiidae: Hesperiinae) – mainly from the southwestern United States and Mexico – off the Carolina coast. Journal of the Lepidopterists’ Society 69(4):275-292.

Leidner AK, and Haddad NM. 2010. Natural, not urban, barriers define population structure for a coastal endemic butterfly. Conservation Genetics 11(6):2311-20.

Leidner AK, and Haddad NM. 2011. Combining measures of dispersal measures to identify conservation strategies in fragmented landscapes. Conservation Biology 25:1022-1031.

 

2018-06-25T16:34:03+00:00 June 25th, 2018|

About the Author:

Ian Grace
Ian Grace earned a bachelor's degree in biological oceanography from North Carolina State University in 2018. As an intern with Michigan State University's Kellogg Biological Station and NCSU's Center for Marine Science and Technology, he has studied habitat ecology and restoration of the crystal skipper, a rare butterfly endemic to North Carolina's Outer Banks. As an undergraduate research assistant, he studied biodiversity variance of western Atlantic deep-sea methane seep communities. He maintains a strong interest in spatial habitat analysis, biodiversity, and conservation.