You may have heard of birds that migrate over great distances to escape the cold and gloomy winter. However, there is an insect that may give birds a stiff competition over migratory distances. Meet the Monarch butterfly, an ordinary insect with a majestic talent!
Photo credit: National Geographic
A natural long distance flyer
Like many other insects such as locusts and dragonflies, they would would migrate to warmer or cooler climates during certain times of the year. This behavioral adaptation is of interest to many scientists. What makes this butterfly so astonishing is the distance it covers, they are able to travel from North America to Mexico and back (a distance of 4828 km!). Moreover, the duration of this journey is longer than its lifespan. Hence, a generation of the monarch butterfly starts the journey and subsequent generation end it. The lifespan of this butterfly ranges from two to six weeks. However, the migration lasts for eight months (February to October). As the original butterflies do not live that long, they reproduce along the way and subsequent generations continue the migration.
Photo credit: Mercury news
Flying thousands of kilometers requires much energy. Consequently, these butterflies are generally light (each weighing less that 1 gram). With its lightweight body, it is able to achieve this feat by using updrafts of warm air, which allows them to glide like some birds to conserve energy during this long journey. Different populations of the butterfly follow different migratory routes. The ones that live in the Rocky Mountains in the USA would migrate to Southern California while those that live in the East of the Rocky mountains migrate to Mexico to look for warmer lands. The butterflies spend the winter in hibernation in the fir and pine forests in Mexico.
The monarch’s mysterious navigation system
Scientists are baffled how these butterflies are able to navigate to their preferred areas as there is no butterfly from the original generation to lead them. It is believed that these butterflies use a sophisticated system known as a time-adjusted compass. Other have considered that they may be using the Earth’s magnetic field to guide them. The video below explains how these butterflies use this tool.
The danger of its extinction
The main threat to this butterfly population is the loss of its habitat, specifically a certain type of milkweed. They rely on this plant for its survival as they lay eggs on it and its the caterpillar’s main source of food.
Various government agencies and focus groups have spent time to identify suitable of saving this species of butterflies. Some have begun focusing on restoring the milkweed population while others are working on protecting the migratory routes. Nonetheless, these butterflies do have an interesting tale to tell for future generations to come.