How Butterflies Work

The Future of Butterflies

Monarch butterflies perch on a tree limb in an overwintering ground in Mexico.
Monarch butterflies perch on a tree limb in an overwintering ground in Mexico.
Photo by Jeff Foott, © Discovery Communications, LLC

If you've ever seen pictures of the famous annual monarch migration, you might think that monarchs are plentiful and in no danger of extinction any time soon. However, illegal logging in the protected Butterfly Biosphere Reserve, which houses part of the monarch's overwintering grounds, threatens the butterflies' survival. Without lots of trees in their overwintering grounds, monarchs have no place to hibernate or begin the next generation of butterflies.

Habitat loss is a serious threat to other butterfly populations, and not just in overwintering grounds. Urbanization and development can quickly destroy the plants where caterpillars eat and butterflies lay their eggs. In addition, some people view caterpillars as pests, especially when they destroy the foliage on carefully cultivated plants. For this reason, some people kill the caterpillars in their garden, preventing them from growing into butterflies.

Although butterflies are clearly not big-game species, human hunting has had an effect on their population. Some species are highly prized by collectors, and over-collecting has caused a sharp decline in their population. For example, several swallowtail species are on the U.S. Fish and Wildlife Service endangered species list in part because of over collecting.

Butterflies' bright colors and unique shapes make them a target for collectors. Butterflies' bright colors and unique shapes make them a target for collectors.
Butterflies' bright colors and unique shapes make them a target for collectors.
© Mike Bentley/iStockphoto

Pesticides are another major butterfly threat -- adult butterflies are extremely sensitive to them. But keeping pesticides away from butterflies' food sources is easier said than done. Wind can carry pesticides far from their point of origin, contaminating butterflies' habitats. For this reason, people who want to encourage butterflies to live in their yards and gardens should rely on natural forms of pest control, such as encouraging the presence of pest-eating insects.

Fortunately, butterflies can live and grow in greenhouses and other indoor locations as long as they have food, water and the right plants. This makes it possible for nature centers and other facilities to care for butterflies and educate people, as well as to try to preserve some butterfly species. However, in spite of such efforts, habitat loss and pesticide use will continue to threaten butterflies worldwide.

To learn more about butterflies, butterfly gardens and related topics, read on to the next page.

Related HowStuffWorks Articles

More Great Links


  • Ajilvsgi, Geyata. "Butterfly Gardening for the South." Taylor Trade Publishing. 1991.
  • Chen, Jian-Hua, et al. "X-ray Tomography and Chemical Imaging within Butterfly Wing Scales." Synchrotron Radiation Instrumentation: Ninth International Conference. American Institute of Physics. 2007.
  • Cizek, Lukas et al. "Host Plant Defenses and Voltinism in European Butterflies." Ecological Entomology. Vo. 31. 2006.
  • Meyer, John R. "Lepidoptera." N.C. State University. 3/8/2005 (3/16/2008)
  • Molleman, Freerk et al. "Food Intake of Fruit-feeding Butterflies: Evidence for Adaptive Variation in Proboscis Morphology." Biological Journal of the Linnean Society. Vol. 86. 2005.
  • Murphy, Dennis D. "Butterflies and their Nectar Plants: The Role of the Checkerspot Butterfly Euphydryas editha as a Pollen Vector." Oikos. Vol. 43, no. 1. 1984.
  • Peggy Notebaert Nature Museum. "The Butterfly Lab." 3/18/2008
  • Rusterholz, Hans-Peter, et al. "Can Nectar Properties Explain Sex-specific Flower Preferences in the Adonis Blue Butterfly Lysandra bellargus?" Ecological Entomology. Vol. 25. 2000.
  • Schappert, Phillip J. "A World for Butterflies." Firefly Books. 2000.
  • Wahlberg, Niklas. "That Awkward Age for Butterflies: Insights from the Age of the Butterfly Subfamily." Systemic Biology. Vol. 55, no. 5. 2006.
  • Wilcott, Elizabeth. "Insect Physiology." University of Arizona. 1/12/2003 (3/16/2008)