I saw in the news that the monarch butterfly is now on the list of endangered species. What does this mean and how can we help? AT

Endangered is a term used by the International Union for Conservation of Nature to identify a species that is in danger of extinction. After studying the monarch butterfly populations over time, scientists have determined the monarch butterfly is in danger of extinction as their numbers have been in decline for several years.

In the United States, we have two Monarch populations with the Rocky Mountains serving as the dividing line. The group known as Western Monarchs summer in Northern California, Oregon, Washington and sometimes even in Vancouver Canada. As summer comes to a close, they migrate south to coastal areas in Southern California.

The monarchs we see in Tulsa are Eastern Monarchs. These monarchs visit our area twice a year; once in the spring as they migrate north and then again in the fall as they travel to their overwintering site in Mexico. Insect migrations of this great distance are rare, and monarchs are one of the few insects to travel such a distance.

As recent as the 1980’s, the Western Monarch population was estimated to be about 4.5 million. By about 2015 that population had dropped to approximately 30,000. 2021 counts estimate the Western monarch population has risen to about 200,000 which is trending in the right direction but considering there used to be millions of western monarchs, not so great.

Eastern monarch populations get counted by how many acres they occupy at their overwintering site in Mexico. As you can imagine, counting individual monarchs would prove challenging, so they measure the land area they fill. During the 2018-2019 overwintering season, they found the monarchs occupying about 15 acres. In 2019-2020 that number dropped to 7 acres. It dipped lower in 2020-2021 but is back to about 7 acres for the 2021-2022 season. At least they are holding steady. But a severe weather event in either population group could have catastrophic results.

One fascinating aspect of their migration that always gives me pause, is that the monarchs that leave Mexico in the spring heading north are not the same ones that return in the fall. In fact, the returning monarchs are separated from the departing monarchs by several generations. This is amazing considering they make their way back to the same overwintering spot in Mexico each year.

There are a variety of amazing videos on YouTube showing the monarch overwintering site in Mexico. So may butterflies in such close proximity is pretty spellbinding.

While a variety of factors influence the downward trend in monarch populations, one of the primary factors is the decline in available natural habitat along their migration paths. This is the result of agriculture and urban development. Combine this with our use of pesticides and we find monarch being added to the endangered species list.

Even though monarch butterflies utilize nectar from a variety of flowers for fuel, to reproduce they need to deposit their eggs on milkweed plants. When monarch eggs hatch, they begin to devour the milkweed plant being able to eat an entire leaf in about a minute. All of this eating helps them to grow about 2700% from their original weight. To put this in perspective, it would be like a 6-pound infant eating enough to grow to about 16,000 pounds in a very short period of time. That’s a lot of eating.

Milkweed plants provide another benefit in that the plants contain a toxin called glycoside. This chemical is toxic to animals which is why it’s a good idea to wear gloves when handling milkweed. Potential predators of monarch caterpillars know them to be toxic which increases the likelihood of monarch caterpillar’s survival. Not a bad survival strategy.

Due to milkweed’s toxicity, if you have dogs, cats, or horses you may want to avoid planting it in a place where they could find it. And when handling it, be sure to wear gloves and don’t touch your eyes.

Planting milkweed is a great way to help the monarchs on their journeys north and south. But if you need to avoid milkweed in your garden, a healthy population of pollinator plants will help also. Also, minimizing or eliminating your use of pesticides will not only benefit the monarchs but all your pollinator insects as well.

Milkweed plants can be purchased from local growers, but you’ll have more luck finding them at herb festivals in the spring or at farmer’s markets. We also make it a point to have a good supply of milkweed available at our spring plant sale.

To learn more about monarch butterflies and how to support them you can visit monarchwatch.orgwhere you can also learn how to become a certified monarch waystation. Xerces.org also has a lot of good information. See you in the garden!

You can get answers to all your gardening questions by calling the Tulsa Master Gardeners Help Line at 918-746-3701, dropping by our Diagnostic Center at 4116 E. 15th Street, or by emailing us at mg@tulsamastergardeners.org. Photo: Steven Katovich, Bugwood.org