Go beyond stickers to save monarch butterflies


How does a sticker on a butterfly save the species? In reality, very few tagged moths are recovered. If you love butterflies, you’ve probably read how monarch butterflies are in trouble. Their population has crashed from historically sustainable numbers and many fear they are on the verge of extinction. As with any species at risk, there are many theories as to the cause and how best to prevent extinction. The tagging program is promoted as a way to save them.

In the 1930s, Canadian zoology professor Fred Urquhart, a butterfly enthusiast, began his journey by trying to find where monarch butterflies wintered in Mexico. He tagged butterflies before they migrated in hopes of following them. The hope was that someone would find the sticker and call the number written on it to report where they had spotted the butterfly. At one point, he scored 7,000 butterflies in a year. In the 1940s he used paper fender stickers. It took many years, but he finally found where the monarchs were wintering.

“Through trial and error, they learned to scrape scales off the bottom of a wing close to the body and fold the sticker around the edge of the wing. The campus legend asks Urquhart to ride a bike with tagged butterflies attached to his handlebars with wire, to see if they could fly with the tags. The Urquharts have printed their office address on each sticker, so butterfly sightings can be reported.” – published in the University of Toronto review 2015

In 2017, I heard about this tagging program that a few groups were involved in. My first thought was how these stickers would affect the butterflies ability to fly and navigate. According to Monarch Watch and Monarch Joint Venture, the stickers are small, lightweight, and don’t interfere with theft. However, anyone familiar with aerodynamics would question the uneven weight distribution since only 1 fender has a sticker. This also means that the ladders under the sticker will no longer be usable. The scales on the wings help insulate the butterfly, help airflow over its wings, help absorb heat, and are very important for flight.

Another concern is the adhesive used on the stickers. Trying to find out what type of adhesive is used on the stickers was impossible. It should be strong enough to withstand constant movement, heat, wind, rain and normal wear and tear. There are less toxic adhesives made from plant-derived cellulose, but none of the tagging groups could confirm what the stickers were made from.

According to Monarch Watch, the results for the 2018 season from August 2018 to November 2019 only had 1,207 sightings. Based on data collected over the years, it is estimated that approximately 1% of tagged moths are recovered. Even if the observations were higher, the rate of return is very low. Adding the concern of toxic adhesive and interference with butterfly flight and tagging doesn’t live up to the promise of saving the monarch.

A chart from Western Monarch Count for Thanksgiving counts from 1997 to 2021 shows the dire situation. In 1997, there were over 1.2 million monarchs reported, but that number dropped to half the following year. In 1999, about 250,000 butterflies were reported although the number of sites monitored has increased. Despite the tripling of the number of monitored sites reported, the butterflies remained about the same.

The causes of the drastic population decline are many, but one of the main ones is the epidemic use of pesticides. It is estimated that Americans use 80 million tons of pesticides each year on their lawns. The development of what little open space is left and the mowing of wildflowers and you see why the monarch butterfly is on the verge of extinction. Click here for the sobering chart. https://www.westernmonarchcount.org/data/

While studying why birds seemed to avoid eating monarch butterflies, Urquhart made a few discoveries. “Under natural conditions, birds are almost never seen feeding on monarch butterflies. This would indicate that the birds know nothing about their taste, as they have never been observed learning that monarchs are inedible. Isn’t it more likely that monarch butterflies don’t elicit a feeding response in birds? -that monarchs don’t look like bird food? (Urquhart, 1957). Monarchs tagged for migration experiments were eaten in large numbers, apparently because their appearance had been altered (Urquhart, 1957). That should be reason enough not to tag butterflies.

Mating pair of monarch butterflies
Mating pair of monarch butterflies

One of the best things to help save the monarch is to plant its host plant. A host plant is on which butterflies lay their eggs. Each species has its own host plant because once the eggs hatch, the caterpillars feast on the leaves and flowers. For monarchs, it’s milkweed, and there are several types of milkweed native to the United States.

Make sure the host plant is native to your and has do not been sprayed with a pesticide, not even temporary. Do your research and find a reputable native organic nursery that grows their own milkweed or will vouch for the grower. Most plants are sprayed by the grower and many nurseries are unaware of this. If you don’t know if the plant has been sprayed, it is best to keep it covered with netting for 2-3 weeks to prevent moths from laying eggs. An egg laid on a sprayed plant will not survive.

The second most important way to help is to never use chemicals in your garden. A healthy ecosystem will take care of itself. The best defense against mosquitoes are birds and dragonflies, so be sure to keep your garden free of chemicals that poison them and their insect food.

A female monarch butterfly laying eggs on its host plant
A female monarch butterfly laying eggs on its host plant.
Newborn monarch caterpillars having their first meal the egg they hatched
Newborn monarch caterpillars having their first meal, the egg from which they hatched.
An adult caterpillar ready to pupate
An adult caterpillar ready to pupate.

After the caterpillar has finished eating, it seeks a quiet place for its metamorphosis. They prefer under twigs and leaves but attach anywhere. If you see tracks hanging in the “J” position, do not disturb them. Once they have made their chrysalis, it takes them a week to hatch into a butterfly. Their pupa looks like a green grape that turns clear the day before hatching. You can see the butterfly inside.

Newly hatched monarchs drying their wings.
Newly hatched monarchs drying their wings.

Engaging the public in citizen science is important, but this is not the program to do it. Help spread the conservation message. Our monarch butterflies depend on it. All photos are of wild butterflies from my organic, pesticide-free garden.

A male resting without stickers.
A male resting without stickers.


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