Butterflies in the United States are disappearing at an alarming rate. A study published in the Science journal reveals that, between 2000 and 2020, the total abundance of these insects has decreased by 22%. This drastic decline reflects a broader environmental threat and underscores the urgency of implementing conservation measures.
The analysis, based on 76,957 studies conducted at 2,478 unique locations, gathered 12.6 million observations of butterflies from 554 species. The results show that the populations of these insects declined at a rate of 1.3% annually in most of the country, with a more severe impact in the southwest.
Although the Pacific Northwest seemed to be an exception with an apparent 10% increase in the butterfly population, researchers warn that this growth is mainly due to a temporary demographic boom of the California tortoiseshell butterfly, which is unlikely to be sustained over time.
The study also reveals that over 100 species reduced their population by more than 50%, and 22 of them suffered losses exceeding 90%. While 33% of the species studied showed significant declines, only 3% recorded population growth.
The crucial role of butterflies
Butterflies not only beautify the environment but also play an essential role in ecosystems. They are key pollinators and contribute to the nutrient cycle, in addition to serving as a food source for birds and other organisms.
Researchers highlight that in the last 50 years, North America has lost nearly 3 billion birds, a decline progressing at a rate similar to that of butterflies. While bees are usually the first to come to mind when discussing pollination, these insects also play a vital role in agriculture. In Texas, for example, butterflies and flies contribute $120 million to cotton production.
A call to action
The scientists behind the study warn that it is crucial to implement conservation efforts at local and national levels. Nick Haddad, one of the researchers, emphasizes that the recovery of butterflies is not an impossible task but depends on the willingness to act.
Among the proposed solutions, experts suggest reducing the indiscriminate use of insecticides and restoring unproductive farmland to its natural state to promote biodiversity.
“We have never had such a clear and convincing picture of the decline of butterflies as we do now,” concludes Collin Edwards, the study’s leader. The loss of these insects not only affects nature but also has far-reaching economic and ecological implications.
US to declare monarch butterfly as an endangered species
The Center for Biological Diversity and other conservation groups requested in 2014 that the monarch butterfly be listed as a threatened species. Following a review and legal agreement, the FWS will decide on the inclusion by December 2025.
Monarch populations are declining due to warmer temperatures, agricultural expansion, and herbicides that hinder milkweed growth.
The Convention on Migratory Species (CMS) warned that climate change could shift milkweed towards the poles, forcing monarchs to migrate longer distances and affecting their reproduction.
Have you visited our YouTube channel? Subscribe now!
