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Monarch butterflies added to Red List of endangered species

Monarch: Butterfly with stained glass like wings in black and orange sitting on many-petaled red flower.
A monarch butterfly rests on a coneflower. Image via Erin Minuskin.

Yesterday (July 21, 2022), scientists with the International Union for Conservation of Nature issued a decision, placing the beloved migratory monarch butterfly on its Red List list of endangered species. They said the butterflies – like all the 147,517 species on the Red List, of which 41,459 are endangered – are threatened primarily by habitat destruction and climate change.

The migratory monarch butterfly is a subspecies of the monarch butterfly (Danaus plexippus). The native population is known for its migrations from Mexico and California in the winter to summer breeding grounds throughout the United States and Canada. The species’ numbers have dropped between 22 and 72 percent over the past decade, according to a new assessment led by entomologist Anna Walker of the New Mexico BioPark Society. The Washington Post reported:

Monarchs in the Western United States are in particular danger: The population declined by an estimated 99.9 percent, from as many as 10 million butterflies in the 1980s to fewer than 2,000 in 2021.

Bruno Oberle, IUCN Director General, commented:

Today’s Red List update highlights the fragility of nature’s wonders, such as the unique spectacle of monarch butterflies migrating across thousands of kilometers. To preserve the rich diversity of nature we need effective, fairly governed protected and conserved areas, alongside decisive action to tackle climate change and restore ecosystems. In turn, conserving biodiversity supports communities by providing essential services such as food, water and sustainable jobs.

Endangered Monarch butterflies

Scientists say that loss of habitat, climate change and pesticide use appear to be the leading factors in the butterflies’ decline. The western population of monarch butterflies is most at risk. They migrate from Mexico and California into the northern United States and Canada. The IUCN said that:

Legal and illegal logging and deforestation to make space for agriculture and urban development has already destroyed substantial areas of the butterflies’ winter shelter in Mexico and California, while pesticides and herbicides used in intensive agriculture across the range kill butterflies and milkweed, the host plant that the larvae of the monarch butterfly feed on.

Climate change has led to droughts and wildfires that limit the milkweed available to the monarchs; and severe weather has killed millions of butterflies as well.

Anna Walker, who led the new study, said there is still hope:

It is difficult to watch monarch butterflies and their extraordinary migration teeter on the edge of collapse, but there are signs of hope. So many people and organizations have come together to try and protect this butterfly and its habitats. From planting native milkweed and reducing pesticide use to supporting the protection of overwintering sites and contributing to community science, we all have a role to play in making sure this iconic insect makes a full recovery.

Butterfly with orange, black, and white wings sitting on pink flower head.
Because the monarch is a widespread species, it can turn up almost anywhere in the US, and there are actions that any of us can take to help it. Planting native milkweed, such as the showy milkweed in this photo, is a valuable step. Image via USFWS Midwest/ Flickr/ Xerces Society.

How you can help

The Xerces Society has issued a call to action with steps that you can take, in your own yard.

Build a pollinator garden: A simple, native flower garden with milkweed will attract butterflies to your yard and help them stay healthy. In addition to nectar from flowers, monarch butterflies need milkweed to survive, so if you notice the leaves on your milkweed have been chomped, it’s a great sign! There’s a step-by-step guide here.

Plant pesticide-free: Learn more about why avoiding toxic pesticides is more important than ever.

Care for a butterfly in your own yard: A female adult butterfly can lay about 400 eggs, and of those 400 eggs, only about eight live to become adult butterflies. One hands-on way to give monarchs a better chance at survival is by collecting the eggs or caterpillars and raising them in protected net cages until the butterfly emerges. Follow these steps.

A child reaches into a large net cylinder with leaves and a butterfly in it.
Only 1 or 2 monarchs per 100 live to adult stage. Raising them in net cages away from predators is one way to help more butterflies reach adulthood. Image via Sharon Kizer.

With the help of Monarch Watch you can obtain stickers to tag your butterflies. These safe, lightweight markers help scientists understand the timing and pace of migration and the geographic distribution of the monarchs.

Orange and black butterfly with a small round printed sticker on its wing.
This butterfly was raised to adult stage in Wisconsin and tagged before its release. Image via Sharon Kizer.
Orange butterfly with black lines in the middle of the wings and in the borders.
View at EarthSky Community Photos. | Lorraine Boyd captured this butterfly on June 3, 2022. It goes to show that even sometimes when we think we’re spotting an increasingly elusive Monarch, sometimes we’re not. As Lisa Ann Fanning pointed out, this is a Viceroy butterfly. As Lisa Ann said: “Viceroys are Monarch mimics because Monarchs are poisonous, and so the viceroy mimics them to avoid being eaten by predators like birds. The main field mark distinguishing them is the horizontal line on the wing. Monarchs do not have that.” Thank you, Lorraine and Lisa Ann!

Bottom line: Monarch butterflies are now listed as endangered on the IUCN Red List. But there are ways you can help.

Read more: What monarch butterflies prefer

July 22, 2022

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