Butterflies are not only colorful flying works of art but they also hugely contribute to our environment by pollinating plants. Sadly, their numbers are declining, as a decades-long study in the US has just disclosed.
The study, led by Tyson Wepprich of Oregon State University, discovered that numbers of common butterflies in Ohio state have dropped by 2 percent yearly, resulting in a 33 percent dip within two decades.
The study was published on Tuesday in PLOS ONE.
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Climate change a factor
The study discovered that climate change and other human-related disturbances were the main factors in this decline. Even though the study was limited to one insect in one state in North America, the findings align with research carried out in Europe.
Wepprich said, "Declines in common species concern me because it shows that there are widespread environmental causes for the declines affecting species we thought were well adapted to share a landscape with humans."
He continued, "Common species are also the ones that contribute the bulk of the pollination or bird food to the ecosystem, so their slow, constant decline is likely having ripple effects beyond butterfly numbers."
It's not just the butterflies we should be worried about, as per Wepprich's concerns.
Three out of four species grew less abundant
Over the years of the study, the team's data from Ohio was able to estimate the population trend of 81 different butterfly species. Unfortunately, they discovered that three out of every four species they observed grew less abundant over the course of their study.
"Species with more northern distributions and fewer annual generations declined the most rapidly," said Wepprich.
On a more positive note, forty species did not move up or down in numbers.
The reason Wepprich speculates that environmental issues may be a core problem in the decline of butterflies is that the researchers discovered that even invasive species were diminishing in numbers.
The common butterfly species is not yet on the list for animals or insects in the risk of extinction, their decline has a powerful negative impact on ecosystems provided by insects, said Wepprich.
If we don't want to see the butterflies disappear, or impact the environmental chain that is linked to their survival, then changes need to occur fast.