Getting to know the Gulf Fritillary butterfly.

By Bill Rhodes ~ Photos By Marta Morton

The biodiversity of islands is unlike most other spots on earth. For example, who can forget learning about Darwin’s scientifically groundbreaking trip to the Galapagos Islands? It was there that he discovered multiple endemic (native and found only there) species, and by examining representatives from the various islands of the archipelago was inspired to begin to shape his theory of evolution through natural selection.

Relying on their distastefulness for protection, the Gulf Fritillary butterfly flies fast and erratically until it alights on a flower for feeding.

Even smaller islands, like the Turks & Caicos Islands, are host to a variety of unique species and varieties. If they happen to be able to fly, like birds and insects, they can be transitory, migratory, or year-round residents.  Those that live here all year likely came naturally, carried to the Islands by strong winds or by simply flying across open water from neighboring islands. Others have taken up residence as “stowaways” inadvertently brought in on goods arriving from elsewhere, or hidden within newly established, but non-native, landscape plants. One of the “burdens” of having such a pleasantly accommodating climate is that once they arrive, non-native species are often happy to call TCI home.

Visitors enjoy observing these native animals, many of which they cannot see at home. There is, of course, the spectacularly colored marine life just a short snorkeling trip away, with a multitude of fish, mollusks, and numerous other invertebrates filling the clear blue, warm surrounding waters. But there are also striking flashes of color that can be seen flying about on land, especially on or near flowering trees and blooming plants.  

There are at least 37 different species of butterflies that can be found on TCI, as recorded and reported by Robert St. Leger in 1991. He was a British amateur entomologist and specialist in lepidoptera (butterflies and moths) who spent five years here in the early 1980s.  Subsequent species sightings have brought the number to about 40—although there has been little organized scientific fieldwork across the Islands—and there are likely more to be found.  

Most can also be seen elsewhere in the Caribbean, some as far north as southern Florida, as year-round residents. For people visiting from the northern US or Europe, though, many of these butterflies are completely new to them. Examples include the large, yellow Cloudless Sulphur, which is most often seen rapidly flying, high in the trees, never alighting close enough to easily observe, and the ubiquitous, fast flying Gulf Fritillary, Agraulis vanillae.

This is the rather frightening Gulf Fritillary caterpillar, who feeds almost exclusively on the passionflower vine, which is laden with toxic chemicals.

The Gulf Fritillary is a medium sized butterfly and is easily spotted, with its bright orange upper side adorned with black dots. Its underside is just as striking, with hindwings covered in silvery white triangles. Even the caterpillars are conspicuous, as they are also bright orange with numerous black branched spines. They feed almost exclusively on different species of passionflower, a type of flowering vine, which, while having beautiful flowers, are laden with toxic chemicals and are found throughout TCI. The Gulf Fritillary caterpillars concentrate the passionflower’s toxins in their bodies, making them not only unpalatable to predators but possibly even toxic. These chemicals are carried over into the winged adults, which hungry birds quickly learn to avoid.

They are classified in the subfamily Heliconini and are more commonly referred to as “longwing“ butterflies, because of their long, narrow forewings. Unlike other longwing butterflies, though, which tend to glide slowly and gracefully in the darker parts of the understory, relying on their distastefulness for protection, the Gulf Fritillary is fast and erratic, flying just about eye level or a little higher until it alights on a flower for feeding. 

It is widespread throughout the Caribbean and southeast US, where some populations migrate north as temperatures rise in the spring, going into the mid-Atlantic states and northern parts of Texas and the Central US. Populations in the far south and Caribbean stay year-round. When a predator approaches, they release chemicals from their abdomen which are unpleasant to the birds and others trying to make a snack of them. If that doesn’t dissuade the would-be diner, they will be sorely disappointed when taking their first bite. 

Like most butterflies, the Gulf Fritillary feeds on nectar obtained from plants, but unlike many other butterflies they can collect pollen as well and use it for nutrients.

Like most other butterflies, they feed on nectar obtained from plants, using their straw-like proboscis. However, unlike most other butterflies, they can collect pollen as well and use it for nutrients as it is absorbed through the proboscis wall. The pollen that sticks to their mouthparts and body also makes them excellent pollinators as they travel from flower-to-flower feeding.

Female Gulf Fritillaries are generally larger than the males, and the males will attract females by perching on a plant and flapping their wings together, open and shut, as a display. They also release chemicals, called pheromones, that the female will recognize and be drawn to. 

So, the next time you see a flash of orange flying erratically by, it is likely another TCI local resident, the Gulf Fritillary.

Bill Rhodes is a retired life sciences industry executive who enjoys writing for various magazines on nature subjects. He lives in southwest Florida for most of the year and enjoys visiting the Islands as frequently as he can.