J is for Jamaican Giant Swallowtail Butterfly

The Jamaican Giant Swallowtail is the largest butterfly species in the Americas and endemic to the island of Jamaica. Adults grow up to three inches with an average wingspan of 6 inches.
This butterfly is now only found in two isolated populations on the island.
Swallowtails differ from all other butterflies in a number of anatomical traits, such as the unique organ that they posses behind their heads as caterpillars, called the "osmeterium." It is normally hidden and out of view, but when the caterpillar feels threatened by predators, it is used to emit a foul smell.
The main threats to the species are loss of habitat and commercial collecting. Conservation efforts include captive breeding and a plan to legally protect the species from collectors.