EVANSVILLE, In. (WEHT) – As the monarch butterfly population continues to decline, the species has been added to the endangered species list.

Experts say monarchs have been on a decline for many years. The International Union for the Conservation of Nature announced the designation as there are many reasons why monarchs were added to the list.

“Pesticides and climate change and illegal logging in Mexico,” Misty Manar, curator for the Botanical Garden at Mesker Park Zoo. “It’s been coming, so we’re not really surprised. It’s definitely sad. Hopefully this will kind of bring more intention to it and get people board to help do something about it.”

The conservation of nature group estimates the monarchs populations has seen a significant decline between 22 and 72 percent. Those declines could lead to problems in the ecosystem.

“Butterflies, especially the monarchs and all other type of insects and bees are essential pollinators,” Lisa Hoffman, park and program supervisor for Audubon State Park said. “So without their existent in our ecosystem we would not have many of the fruits and vegetables that we rely on for foods.”

Audubon State Park as well as Mesker Park Zoo and Botanical Garden have worked to create environments for the monarchs, but both say they have noticed a drop in their numbers each year.

“Been here a couple decades so I can definitely say in the decades I’ve been here we don’t see as many butterflies as we use to, monarchs as well,” Manar said.

Milkweed is the host plant for monarchs. It is essential because that is the only plant where monarchs will lay eggs. However, essential to butterflies doesn’t mean essential to the average person.

“For many milkweed is considered a noxious weed so the milkweed is removed. So you take away that essential plant, you’re going to reduce the number of butterflies that you have,” Hoffman explained. “There’s also some evidence that milkweed plants are being affected by higher ozone levels.”

Manar says there is a possibility that many other butterfly species are close to being on the endangered species list due to many of the same reasons.