Monarch Migrations

Monarchs are one of the most amazing creatures on the planet. Learn more about what it will take to sustain healthy populations at:

It seems a little strange to be thinking about monarch butterflies, or any insects for that matter, as winter officially starts today. We spent the last week in Yuma, Arizona, though, just 20 miles from Mexico and a stone’s throw from California. We saw a monarch butterfly and I guess that set everything into motion.

This particular butterfly was alone and it immediately had me wondering about its story. Was it a locally grown monarch? Had it strayed from a large migrating group of monarchs? Was it somehow injured and unable to keep up?

Monarchs are migration marvels. It seems a strange behavior for an insect, most of which tough out the winter in a near frozen state or die after laying eggs that carry on their legacy the following spring. It is especially puzzling when you consider that the monarchs that migrate home to summer range are not the same ones that migrate back to winter range up to 2,000 miles away. Since summer monarchs live only two months, several generations separate them, meaning that no monarch that heads south has ever seen the land it is heading to or the pathway that leads to it.

Although the lifespan of a summer monarch is two months, those that make the southern journey live longer. They are called the super generation and they bear a significant burden. In their seven months of life, they journey to and from the winter area and lay the next generation of eggs.

Through citizen science research, the migration routes of many monarch populations have been documented. Almost all monarchs from the east and central states funnel into a tiny overwintering ground in southern Mexico. Populations west of the Rocky Mountains winter along the coast of California.

The small location in Mexico is really just that. Managers have calculated the actual occupied forest of the entire wintering eastern population at 7.19 acres for the winter of 2016-17, down from 9.91 acres the previous year. The tiny footprint is because monarchs gather in huge clusters clinging to a single tree and each other. These individual trees may support a million butterflies, making each tree tremendously important.

These highly concentrated winter populations are wildly vulnerable to habitat changes and weather. The trees that the monarchs overwinter on are valued by locals for income, construction and firewood. And even if select trees are protected, like holes in a blanket, removing neighboring trees can expose the butterflies to deadly winter weather. In 1995, a single storm killed an estimated six million monarch butterflies, repeating a similar episode that occurred in 1992.

Although the summer homes of monarchs are widely scattered across thousands of square miles, they are equally susceptible to change. Monarch caterpillars feed only on many varieties of milkweed. Through habitat conversion and the targeting of milkweed as a noxious weed, habitat for monarchs on summer ranges has declined precipitously.

Monarchs have been the state insect of Idaho for 25 years. But they are in danger of failing the Idaho state motto, Esto Perpetua (roughly translated, may this be forever). It seems rare these days to see a monarch in eastern Idaho.

If you want to give nature a Christmas gift this year, plan now to establish a pollinator garden in the spring, one that is heavy on milkweed. As individuals, we can’t do much about what happens in Mexico, but we can do our part to reverse habitat loss in their summer ranges.


Help Idaho Wildlife

When we traveled across the state in October 2017, most of the vehicles we saw using the wildlife management areas did not have wildlife plates. Buying wildlife plates is a great way for non-hunters and hunters alike to support wildlife-based recreation like birding.

C'mon folks, let's help Idaho's wildlife by proudly buying and displaying a wildlife license plate on each of our vehicles! 

See below for information on Idaho plates. Most states have wildlife plates so if you live outside Idaho, check with your state's wildlife department or vehicle licensing division for availability of state wildlife plates where you live. 

And tell them that you heard about it from!

Wildlife License Plates

Idaho Wildlife license plates provide essential funding that benefits the great diversity of native plants and wildlife that are not hunted, fished or trapped—over 10,000 species or 98% of Idaho’s species diversity. Game species that share the same habitats (such as elk, deer, antelope, sage-grouse, salmon, trout) also benefit from these specialty plates.

No state tax dollars are provided for wildlife diversity, conservation education and recreation programs. Neither are any revenues from the sale of hunting or fishing licenses spent on nongame species. Instead, these species depend on direct donations, federal grants, fundraising initiatives—and the Idaho Wildlife license plates.

Both my vehicles have Bluebird Plates. I prefer the bluebird because the nongame program gets 70 percent of the money from bluebird plates, but only 60 percent of the money from elk and trout plates - 10 percent of the money from elk plates supports wildlife disease monitoring and testing programs (to benefit the livestock industry) and 10 percent from cutthroat plates supports non-motorized boat access.

Incidentally, in 2014, the Idaho Legislature denied the Department of Fish and Game the ability to add new plates or even to change the name of the elk and cutthroat plates (very specific) to wildlife and fish plates, a move that would have allowed for changing images occasionally and generating more revenue. It would seem that they believe that we Idahoans don't want a well funded wildlife program.

I think it is time we let the Legislature know that Idahoan support wildlife funding and that we would like to see these generic plates come to fruition.

"WOW. What a phenomenal piece you wrote. You are amazing." Jennifer Jackson

That is embarrassing, but actually a fairly typical response to my nature essays. Since The Best of Nature is created from the very best of 16 years of these nature essays published weekly in the Idaho Falls Post Register (online readership 70,000), it is a fine read. It covers a wide variety of topics including humorous glimpses of nature, philosophy, natural history, and conservation. Readers praise the style, breadth of subject matter and my ability to communicate complex and emotional topics in a relaxed and understandable manner.

Everyone can find something to love in this book. From teenagers to octogenarians, from the coffee shop to the school room, these nature essays are widely read and enjoyed.

Some of the essays here are my personal favorites, others seemed to strike a chord with readers. Most have an important message or lesson that will resonate with you. They are written with a goal to simultaneously entertain and educate about the wonderful workings of nature. Some will make you laugh out loud and others will bring a tear to the eye and warm your heart.

Readers Write:

"You hit a home run with your article on, Big Questions in Nature. It should be required reading for everyone who has lost touch with nature...great job!" Joe Chapman

"We enjoyed your column, Bloom Where Planted. Some of the best writing yet. The Post Register is fortunate to have your weekly columns." Lou Griffin.

To read more and to order a copy, click here or get the Kindle version 


Copies are also available at:

Post Register

Island Park Builders Supply (upstairs)

Barnes and Noble in Idaho Falls

Harriman State Park, Island Park

Museum of Idaho

Valley Books, Jackson Wyoming

Avocet Corner Bookstore, Bear River National Wildlife Refuge, Brigham City, Utah

Craters of the Moon National Monument Bookstore, Arco, Idaho