Monarch Conservation in West Texas

Monarchs roost in a pecan tree in Alpine, Texas

The sun is setting as I sit on the picnic table and just watch. Monarchs swirl around me by the hundreds—or is it thousands? They begin to settle, landing in rows on the bare branches of the old pecan tree near Kokernot Lodge in Alpine. They’re restless though, and burst into flight again when a newcomer tries to squeeze into the row. A swirl or two and they resettle on a clump of leaves. More butterflies float in from the north and jostle for space. I am amazed by the utter silence. A butterfly wing doesn’t even whisper.

Monarch Migration
Monarchs are one of the few insects that migrate in great round-trip journeys from their summer breeding grounds in the north, to sites in the south where they overwinter. In the spring, they head north again. The earliest report of monarchs migrating south was published in a Canadian journal in 1857. The author, W.S.M. D’Urban, noted that monarchs appeared in the Mississippi Valley “in such vast numbers as to darken the air by the clouds of them.” But it took another 120 years to discover where they were going.

In the late summer, as the nights grow cooler and the days grow shorter, a generation of monarchs emerges from their chrysalides that are biologically and behaviorally different from the generation before them. These monarchs won’t mate or lay eggs until the following spring. Their driving instincts are to find food and fly south.

They travel in pulses, often driven by cold fronts that bring the wind from the north, sometimes traveling 150 miles in a single day. Late in the afternoon, the butterflies seek a place to spend the night—in Texas, this is usually a pecan or oak tree near water. Although monarchs do not migrate in flocks as birds do, individual monarchs seem to seek each other out to form roosts of hundreds to thousands of butterflies. The next day, warmed by the morning sun, they will continue their journey south.

When the winds are unfavorable, monarchs stay on the ground, nectaring on goldenrods, gayfeather, and mistflowers. These nectaring stops allow the monarchs to build up fat reserves that will sustain them throughout the winter.

By late September, all of the monarchs from the 5.2-million-square-mile breeding grounds east of the Rocky Mountains funnel into Texas. Most years, the monarchs will travel through Texas along the central flyway, a broad swath of land 300 miles wide and centered on a line between Wichita Falls and Eagle Pass. They are headed for the fir forests of the Transverse Neovolcanic Belt near Mexico City, a place that none have been before, but that millions will find.

Monarch Conservation
D’Urban’s skies darkened by clouds of monarchs are pretty much gone. In fact, some predict that the great monarch migration may be a biological phenomenon that winks out in our lifetime. Illegal logging of forests in Mexico, changing climate in both the overwintering grounds and the summer breeding grounds, and the decrease in nectar and larval host plants are all taking their toll.

A world without monarchs scares people, so many organizations and agencies are jumping on the monarch conservation bandwagon. Yesterday, Texas Parks and Wildlife Department released the Texas Monarch and Native Pollinator Conservation Plan (October, 2015) or perhaps better titled The I-35 Monarch Conservation Plan. Don’t get me wrong. I’m proud of TPWD and the many partners listed in the report for recognizing the critical role that Texas plays in monarch conservation and for wanting to do something about it. But—ahem—that beautiful flyway map produced by Monarch Watch? It’s just an average. Monarchs scoff at sharp lines on human-drawn maps. This year, thousands are monarchs are passing through Fort Davis, Alpine, Marathon, and Terlingua on their way to Mexico. As they have in the past and they will in the future.

Fall Migration 2015

Journey North map of the 2015 Fall Monarch Migration

 

This particular pet peeve of mine is not new. About 10 years ago, I read an article about a monarch tagging project being conducted by the Southwest Monarch Study of Arizona. They were finding that many of their monarchs chose to overwinter in sunny California rather than Mexico. This got me thinking about the Trans-Pecos monarchs. Where were they going?

I eagerly contacted the Southwest Monarch Study and asked to be part of their tagging program. “You’re too far east,” they told me. “Contact Monarch Watch.” Monarch Watch told me to contact Texas Parks and Wildlife and Texas Parks and Wildlife told me we were too far west for our monarchs to be of any interest.

I gave up, but the monarchs haven’t. In fact, the frequency of the monarch migration through west Texas seems to be increasing. Don’t quote me on this. It’s just a hunch without any supporting data. But it is an interesting research question. How does the monarch migration fluctuate over time and what are the triggers that cause a shift of the central flyway? What does long-term climate research predict for our region? Will El Nino patterns increase in frequency, resulting in wetter Fall weather and increased nectar sources for monarchs?

Conservation plans need to be pro-active and prepare for a changing future. I know that it’s easiest to focus on what we see today and concentrate on urban areas because funding is often about numbers (how many school children can you reach per dollar spent?), but if you’re truly interested in monarch conservation, think broadly and include west Texas in your planning.

In the meantime….
As I climb off my soapbox (will someone please hold the ladder?), I have some suggestions:

1) Plant for fall migration. You’ll read a lot about the need to plant milkweeds for monarchs. Milkweeds are important, it’s true, but in the fall, monarchs need nectar sources. A 2006 study of lipids (energy storage molecules) in migratory monarch butterflies showed that once monarchs get to Texas, they pause to nectar and build up their lipid reserves before continuing on to their final destination in Mexico. These lipid reserves are critical to their survival over the winter. Texas wildflowers are critical to their survival over the winter.

2) Go to the Big Bend Chapter of the Native Plant Society of Texas Facebook page and post an image of plants that you’ve seen monarchs use for nectaring. Let’s develop a list specific to this area for homeowners, landowners, and government officials that can be used for everything from large-scale restoration projects to home gardens.

GoldeneyeGregg's MistflowerAnnual Goldeneye
Texas GayfeatherMilkweedThistle
Fall blooming flowers such as sunflowers, mistflower, Annual Goldeneye, Gayfeather, milkweeds, and thistles provide important nectar sources for migrating monarchs.

 

3) While we would all like to think that our backyard gardens are Making A Difference, here’s what the 2006 monarch study has to say: “The popularity of butterfly gardens and native plant landscaping may enhance pollinator populations locally, but will never be of sufficient magnitude to compensate for the losses of native nectar sources from rural habitats.” Damn.

This isn’t to say that you shouldn’t be planting your monarch café. Please do. But also think bigger. Did you know that there are over 4 million miles of roadsides in the United States? I don’t know how many in Texas, but I’ve driven over 1,000 of these miles within the last week, so I can tell you that there’s a bunch. Thousands of miles of roadsides fenced off from grazing animals and protected from development.

The Texas Department of Transportation is responsible for managing these roadsides. They even have a wonderful document titled Roadside Vegetation Management Manual: Guidelines for Levels of Vegetation Management. Take a look at it. It’s great.

Unfortunately, when I called TXDOT one year to register a complaint about the mowing of a huge stand of gayfeather in full bloom, I was told the guidelines are “suggestions, not policy.” I think Texans and Texas deserve better than that. Make yourself familiar with the guidelines and work with your local TXDOT office to let them know that you care.

3) Post observations to Journey North. The only way they’ll know about the monarchs of west Texas is if we tell them.

This entry was posted in Chihuahuan Desert, Insects, Plants.

One Comment

  1. Laura Belkin October 30, 2015 at 3:09 pm #

    I have seen Monarchs, one or two at a time, on morning walks past the Marfa golf course where there is a tank with trees around it. I have not seen them feeding though there are the usual roadside flowers.

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