As climate change becomes an increasingly prevalent issue throughout the state of Colorado, the local butterflies are feeling the effects. Butterflies, as pollinators, are critical to the long-term viability of our state’s ecosystem.
Unfortunately, butterfly populations have been decreasing drastically over the past 50 years due to increased temperature across Colorado, loss of vegetation like milkweed and wildflowers, and increased pollution. A recent study by the Colorado Department of Natural Resources suggests that Colorado’s butterfly population has decreased by over 50% in the last 35 years.
How concerned should we be about Colorado’s falling butterfly population? Is this indicative of more scary and drastic climate-induced changes to come? On December’s episode of the Bucket List Community News Podcast, we sat down with Shiran Hershcovich, senior lepidopterist at Butterfly Pavilion in Westminster, to talk about the role climate change has played on the butterfly population and how it affects everyone.
“Butterflies are an extremely essential piece of life here in Colorado,” Herschcovich said. “They help plants grow and those plants in turn give us food and clean air, so they’re pretty essential.”
Hershcovich agrees that climate change has had a negative impact on the butterfly population in Colorado.
“[Climate change has affected butterflies] pretty drastically,” Hershcovich said. “And one of the worst things is that it’s really hard to quantify because only now are we starting to really study the effects of climate change on invertebrates as a whole.”
Shiran says that there’s a lack of information about butterfly populations in Colorado over the last 10 to 20 years, but the decline in numbers transcends statistics. Through her work, Shiran often hears anecdotes about how few pollinators people see in the state in comparison to years ago.
“I get approached all the time and people tell me, ‘I used to see hundreds of butterflies in my backyard and now I don’t remember the last time a butterfly came through my space,’” Hershcovich said. “We have all of these very scary stories and big gaps in our data, so it’s very important to start understanding it.”
From the data that Herschcovich and her team do have, they have concluded that as Colorado’s climate gets drier, an increased danger is posed to the butterfly population.
“[2024] was actually quite a difficult year for butterflies,” Hershcovich said. “We saw a decline compared to last year. Dry conditions and hot conditions are tough for plants, and in turn, butterflies.”
When it comes to climate change, Hershcovich says that butterflies are a good indication of things to come. When butterfly populations decrease, that is typically a sign of more drastic climate-induced changes on the horizon.
“When a habitat is degraded, butterflies are almost like canaries in a coal mine,” Hershcovich said. “They tend to be one of the first animals to crash and disappear.”
One specific butterfly species that has been greatly impacted by climate change is the migratory monarch, whose migration route crosses through the eastern plains of Colorado in late November. Unfortunately, their current migration is in serious danger.
“Monarch butterflies have been in a steep decline for a number of years,” Hershcovich said. “The migratory monarch has lost almost 80% of its numbers.”
Unsurprisingly, the migratory monarch’s steep decline is due to climate change. As vegetation around the country becomes more and more sparse, migratory monarchs are unable to refuel themselves on their 3000-mile trip to central Mexico.
“The migratory monarch has lost so much of their number when they do counts in the winter, and this is because their migration is getting harder and harder,” Herschcovich said.
Hershcovich likens the current migration of the monarch to a road trip where every gas station is closed, so you cannot refill your tank.
“Imagine if you were going on a very long road trip and you stop at the first gas station and it’s closed,” said Hershcovich. “You go to a second gas station and it is also closed. You stop at the third one and that one is also closed. At this point, you are low on fuel and you might not make it through your road trip. That’s kind of what’s happening with monarchs, with so much of their habitat being degraded, damaged or lost entirely.”
Thankfully, steps are being taken to help preserve the migratory monarch. On December 10, the US Fish and Wildlife Service announced a proposal adding the monarch butterfly to the threatened species on the endangered species list. Hershcovich says that’s a big step to help protect a species in decline.
“[Adding monarchs to the endangered species list] is actually a pretty huge step,” Hershcovich said. “Invertebrates rarely get the attention they deserve, despite being so important and so essential for the world to function as we know it … I think it’s definitely a step in the right direction.”
Hershcovich says it’s not too late to make changes to help preserve Colorado’s butterfly population. “There is absolutely hope,” Hershcovich said. “Insects are one of the [most] resilient groups of animals in the world and they should bounce back given the opportunity. We just have to give them that opportunity to thrive again.”
To give butterflies that opportunity to thrive, there are things that Colorado residents can do in their everyday lives to help the cause.
“We have the power to plant native plants in our backyard,” Hershcovich said. “We can plant host plants for butterflies and help them grow and reproduce in our very own backyards. Our very homes can become laboratories and spaces to support the conservation of invertebrates.”
