In news– Recently, the migratory monarch butterfly was declared as ‘endangered’ in the International Union for Conservation of Nature (IUCN) Red List of Threatened Species.
Migratory Monarch butterfly-
- It is a subspecies of the monarch butterfly that travels around 4,000 kilometres across America each year.
- The monarch butterfly or simply monarch (Danaus plexippus) is a milkweed butterfly (subfamily Danainae) in the family Nymphalidae.
- Its other common names, depending on region, include milkweed, common tiger, wanderer, and black-veined brown.
- Monarchs, the most recognisable species of butterfly, are important pollinators and provide various ecosystem services such as maintaining the global food web.
- Most of these butterflies winter in the California coast and forests in central Mexico. A smaller population of the species is also found in countries like Australia, Hawaii and India.
- Habitat destruction and climate change are mainly responsible for pushing the insect towards extinction.
- These butterflies follow a unique lifestyle, they traverse the length and breadth of the American continent twice a year, feasting on nectar from a variety of flora.
- But they breed in only one particular plant, the milkweeds. The monarch larvae feed on this species on hatching.
- The removal of this breeding ground by farmers because they are ‘weed’ is an important driving factor for the dwindling numbers.
- In the 2000s, glyphosate, a weedicide, was widely used in farms in the Midwest. This killed much of the milkweed, where the female monarchs lay their eggs.
- Climate change has made the conditions worse by making storms and droughts more intense and disrupting flowering cycles, according to conservationists.
- Drought limits the growth of milkweed and increases the frequency of catastrophic wildfires, temperature extremes trigger earlier migrations before milkweed is available, while severe weather has killed millions of butterflies.
- Their population in the continent has declined 23-72 per cent over the last decade.
- The number of the western monarchs, which live west of the Rocky Mountains, reduced 99.9 per cent, falling to only 1,914 butterflies in 2021 from 10 million in the 1980s.
- The population of the eastern monarchs that migrate from eastern United States and Canada — the bigger group — also shrunk 84 per cent from 1996-2014.
- Conservation efforts such as protecting wintering grounds and breeding sites have led to a small, but necessary, increase in the monarch count.