Just like birds and sea turtles, monarch butterflies have an internal compass. The sun keeps them on course when they migrate to Mexico, but they can also navigate at night or on cloudy days because they use Earth’s magnetic field as a backup system.
Among the two species of Monarch butterflies, the one in North America differs from the one you will find in South America, but the Caribbean is home to both species. You can also see them in Australia, New Zealand, and several Islands lying between Australia and Tahiti, in parts of Europe and in Hawaii.
A black spot on an inside surface of its hind wing distinguishes the male Monarch butterflies from the females that have no such spot.
They have a 10 cm wingspan and weigh between 0.25 to 0.75 grams. The wings flap slower than other butterflies at about 300 to 720 times a minute and they use their smell and vision help the Monarch butterflies to assess its environment.
Monarch butterflies store a poison called Cardiac Glycosides that they had ingested by feeding on the leaves of the milkweed foliage in their larva stage. These are sometimes harmful to its vertebrate predators, but ineffective on invertebrate predators. The toxic effect on vertebrates however, depends on the level of intake. These toxins provide these butterflies with a poisonous defense against its predators such as lizards, birds, and frogs. Speaking of milkweed…this is the food of choice for the monarch. Don’t destroy the milkweed…plant some milkweed. Feed the Monarch.
