Colorful Poison Dart Frogs can go Invisible; Researchers Say

Researchers explain how poison dart frogs ( of the Dendrobatidae family) use their colourful markings to disappear. The study could help design better camoflouge suits for the army.

The colourful poison dart frogs can be found in forests of Costa Rica and Brazil. They display a tactic called aposematic coloration to escape potential predators. Some frogs in the species do accumulate venom from plants, ants and other creatures. According to National Geographic, poison dart frogs raised in captivity never develop venom.

The study team at Deakin University's Centre for Integrated Ecology wanted to solve a paradox seen in some individuals of poison dart frogs.

 Some individuals in the poison dart frog species use colourful markings on their bodies to warn other creatures that they are poisonous, while other individuals use the rainbow hues to become invisible.

The paradox is that having variability in color patterns would make it difficult for the predator to learn that the frogs carry toxins. Researchers have now found that the frogs have combined colourful patterns on their body with specific body movements to ward off attackers.

Researchers studied the vibrant blue and yellow poison dart frogs (Dendrobates tinctorius), which lives in the French Guiana. Bibiana Rojas, one of the study authors, found that some of these frogs have subdued, variable markings while other have bold colorful designs.

The team found that the more variable the designs on the frogs, the less likely they were to be seen by the predators, Sydney Morning Herald reported.

Professor John Endler of Deakin University said that some frogs moved in a specific pattern while others moved in a random way. This movement was linked to the pattern of designs on the frogs' body.

"The frogs with elongated patterns moved continuously in the same direction to create an illusion of static pattern, or a pattern travelling at a slower speed, to thwart predators attempting to track their trajectory," Endler said in a news release.

"But frogs which moved randomly and changed directions frequently, rely on interrupted colour patterns that appear visually disruptive and hard to see at a distance, giving them an advantage in predator detection rather than tracking," Endler added.

Researchers are optimistic that their study will help other scientists design better camoflaudge suits.

The study, "Paradox lost: variable colour-pattern geometry is associated with differences in movement of aposematic frogs," is published in the journal Royal Society Journal Biology Letters.