Story Behind the Science
Swallowtail butterflies get their name from the tail-like addition to their hindwings, which resembles the forked wings of a swallow. This family of butterflies boasts the largest in the world, including the birdwing butterflies among many others. Some swallowtails fly at higher elevations than most other butterflies, resulting in them often being misidentified as birds. In addition to their large size, swallowtails are regarded for their diversity in color and pattern. Because of their distinct visual differences from other butterflies, swallowtails are some of the most easily recognizable butterflies, even to non-specialists.
Swallowtail caterpillars are usually large and smooth, and they have a horn-like appendage hidden in their thorax. When threatened, swallowtail caterpillars may rear their head back and will reveal this horn, which releases chemical repellants, in an effort to deter predators from further attack. Also, these caterpillars have large eyespots that are used to trick predators into thinking that the caterpillar is larger and more intimidating than it really is.
Swallowtail butterflies, much like many other insects, may be perceived either as a threat or as threatened. Some swallowtails may feast on carrots, in addition to orange or lemon trees, making them a pest in terms of these specific crops, however, this is not very common. As a family, swallowtails are greatly threatened by human activity. Though natural climate changes and events, such as hurricanes and freezes, pose as a threat to swallowtail populations, there are many other human-initiated threats that are more destructive to these butterflies, including collecting for butterfly trade and the use of pesticides to control mosquito populations.
One species, the Schaus swallowtail butterfly, was listed as an endangered species in the 1970s with populations reaching as low as a few dozen in the 1990s. This species lost quite a bit of its natural habitat of hardwood hammock as a result of human productivity. Additionally, mosquito control practices, overcollecting for trade and naturally occurring hurricanes in the ’90s caused further population decline.
Did You Know?
- Not all swallowtail butterflies have “tails” on their hindwings.Learn More »
- Female tiger swallowails are dimorphic, so they may appear in two possible forms: (1) comparable to male tiger swallowtail but with larger blue marks on hindwings, or (2) all black with similar blue marks on hindwings.Learn More »
- A few species of swallowtails might occasionally migrate, but this isn’t a very common practice for this butterfly family.Learn More »
- The word “butterfly” may have originated from the expression “butter-colored fly.”Learn More »
- Peru is the home of the most butterfly species, with 3,700 species recorded and possibly 4,200 to be discovered.Learn More »
|Compare & Contrast||Swallowtail Butterflies||Butterflies|
|How many species?||Over 550||Estimated between 18,000 and 21,000|
|Where do they occur?||The majority of swallowtails live in tropical environments, though species can be found on all continents aside from Antarctica. They are particularly abundant in East and Southeast Asia.||Butterflies can be found worldwide, though they are most abundant and diverse in the tropics.|
|What do they eat?||Some swallowtail caterpillars only eat specific plants and flowers. As butterflies they sip nectar, mud and manure.||Flower nectar, sap, rotting fruit, dissolved mineral salts from mud or dung and carrion are common sources of food for butterflies, though some species have very specialized diets.|
|Do they have predators?||Birds, flies, wasps, ants, mantids, spiders, beetles, frogs, toads and mice||Birds, reptiles, amphibians, small mammals, spiders, wasps, hornets, dragonflies, crickets and mantids|
Getaway Moments, “A Swallowtail is Born”
Conservation Organizations for Butterflies
- Butterfly Conservation: Saving Butterflies, Moths and Our Environment
- Butterflies and Moths of North America
- The Butterfly Conservation Initiative
- Butterfly Conservation, The Xerces Society for Invertebrate Conservation
- Butterfly Conservation Europe