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The Monarch Butterfly vs. South Dakota Politics

Monarch Caterpillar - Danaus plexippus

A Monarch Caterpillar having lunch. This was taken in a roadside ditch in Minnehaha County, South Dakota, but it’s not nearly as common a sight as it could (should) be. Ditches here are mowed, sprayed, and otherwise managed, resulting in ditches (even on rarely used gravel roads) often looking like golf courses or urban lawns.

Yesterday I birded several locations to the northwest of Sioux Falls. I traveled through not only Minnehaha County (where Sioux Falls is), but also nearby McCook, Lake, Kingsbury, and Brookings counties. When I go birding around here, I typically travel on gravel roads, to minimize interaction with other cars and reach places where I can actually stop and watch for a while. While traveling gravel roads through these counties yesterday, I was struck by the incredibly variable management of roadside ditches.

What’s that? You don’t pay much attention to the ditches when you’re driving? I can’t say I normally do either, but I was recently at the North American Congress for Conservation Biology Conference (NACCB), where there were a number of presentations on the plight of the Monarch Butterfly. They’re a species dependent upon milkweed. One of the problems is that SO much of the United States landscape is now being used for agriculture, urban development, energy development, and other uses, and milkweed is crowded out.  Even in areas adjacent or near to agricultural land, herbicides are often used for weed control, further reducing milkweed abundance.

This spring, I was contacted by researchers who were studying landscape change, and how it potentially impacted Monarch Butterflies. Specifically, they were interested in using our landscape modeling to look at future landscapes, and the resultant impacts on both milkweed and Monarch butterflies. In the model they used, they were assuming that roadside ditches in most areas were places where milkweed was likely to be found.

As I quickly learned on my drive yesterday, that characterization is clearly NOT true in many areas, and seems to be strongly driven by local politics, in terms of local land management.  When driving in Minnehaha County, I often come across sprayer trucks, actively spraying herbicide in all the ditches to keep herbaceous weeds in check.  I also often come across tractors with mowers attached, mowing the ditches close to the ground.  Yes…even for the GRAVEL roads that rarely get traffic, the ditches are treated in this manner.  The result? The ditches around here often look like a well-manicured lawn (see photos below).  Hell, they often look BETTER than my yard does!! They often consists of nearly 100% brome grass (an exotic, BTW), while milkweed stems are few and far between, and are typically relegated to small spaces where a sprayer didn’t reach.

When driving through parts of Kingsbury and Brookings counties, I was struck by the incredible difference in the ditches. Many ditches clearly hadn’t been mowed in some time, if they were ever mowed. Grasses were mixed with wildflowers, other herbaceous plants, and yes…MILKWEED (see more photos below).  Milkweed was often present in very high abundance.  The issue clearly isn’t adjacency with actively growing agricultural crops. As the photos below show, the Brookings and Kingsbury County ditches often had an abundance of herbaceous plantlife in areas directly next to corn and soybean fields.

It is possible that I just happened to drive on some gravel roads yesterday in Kingsbury and Brookings counties where no action was taken, but spraying was occurring elsewhere.  On the Brookings County website, for example, I was disappointed to find this page, that notes the county DOES spray right-of-ways with “products such as 2,4-D, Tordon 22K, and possibly mixtures of them“.  They do note on their web page that they spray in May, so clearly they don’t spray all ditches, as the photo below (with the milkweed) is on a gravel road on the very western edge of Brookings County.

During the NACCB conference, one talk I heard focused on recovery efforts for the Monarch, and plans in place to improve Milkweed abundance and improvement. Even a dead-red, conservative state like Oklahoma is taking action, with the Oklahoma highway department specifically managing ditches for Monarch and pollinator habitat. They are specifically planting wildflowers and milkweed along highways in an effort to help not only Mmnarchs, but other species that depend on these plants. The discussion at the conference was a similar “Monarch Highway” stretching from Texas up northward through southern Canada, an area with highway ditches specifically devoted to herbaceous plants, including Milkweed.

Could such a thing happen up here in South Dakota? I’ll see it when I believe it. We have such an focus on agricultural production, that I find it hard to believe they’d accept any land management action that could possibly harm that production in any way.  Not that I BELIEVE an aggressive, pro-Milkweed, pro-Monarch Butterfly agenda would harm agricultural production, but in this VERY red state, environmentalists are usually portrayed as the enemy.  For a large portion of the populous here, I have no doubt they’d view a program like Oklahoma’s as an attempt by environmentalists to meddle in local affairs.

It’s hard to imagine now, but when we moved to South Dakota 25 years ago, our Congressional delegation was completely Democratic. Hell, we had Tom Daschle as a Democratic Senate Majority Leader.  How times have changed. Serendipity may have led to the 3 Democratic Congressional delegates 25 years ago, but in today’s anti-environmentalist concerns for issues like the Monarch Butterfly as far removed from most South Dakotan’s minds.

Minnehaha County Roadside Ditch

I wish my yard looked this green, lush, and free of weeds. Driving home yesterday through northern Minnehaha County, THIS is what roadsides looked like. Even for lightly traveled gravel roads such as this one. Frequent spraying and mowing ensure a monoculture of brome grass, with nary a milkweed stem in sight.

Brookings County Roadside Ditch

In contrast to the Minnehaha County ditch, this is what I saw in many parts of Kingsbury and Brookings Counties. This ditch clearly hadn’t been mowed or sprayed this summer, and was full of herbaceous plants other than brome grass, including many milkweed stems.

 

 

 

Evolution in the blink of an eye…

Prairie Deer Mouse - Peromyscus maniculatus bairdii

The cool thing about science and nature is that interesting stories are all around us. The tiny Deer Mouse, shown here, has overcome long odds, with the vast majority of its historical habitat gone. However, through some remarkable, fast-track evolutionary adaptation, they’re now able to cope with their new world. Photo by Gregory Smith.

It’s been a busy last week, without any time for birding or photography.  Or blogging, for that matter. I was down in Nebraska for a few days, mixing work and pleasure. The “pleasure” part was my fantasy baseball draft in Omaha Saturday.  Our fantasy league is likely one of the longest running leagues in the country, going back to 1985 during our freshman year in college, when fantasy baseball was still very new.  What’s great about it is that many of the original league members are still participating! It’s great fun, not only the draft itself, but catching up with old college friends.

The “work” part of my Nebraska trip was participation in the 2017 Great Plains Symposium, on the campus of the University of Nebraska-Lincoln. Much like the baseball draft, the symposium too was like stepping back in time, as I reconnected with some of my old college professors who were participating in the symposium. The focus of the symposium was “Flat Places, Deep Identities: Mapping Nebraska and the Great Plains”.  I gave a talk one some of the work I’ve been doing, mapping past, present, and potential future landscapes in the Great Plains.  It was a great symposium, a little different kind of crowd than I’m used to.  Given the work I do, most of the conferences and symposiums I attend deal with the physical sciences. This conference melded mapping, history, socioeconomics, and other social sciences that I’m not exposed to as much.  It was quite fascinating, particularly hearing about the history of Nebraska, using maps to help tell the “story” of change over time.

As part of the symposium “goodies”, participants were given a copy of The New Territory, a quarterly magazine that focuses on Missouri, Arkansas, Kansas, Nebraska, and Oklahoma.  I admit I’d never heard of the publication before. The content fits quite well with the focus of the symposium itself, with many human interest stories about the geography and people of the region. As a physical scientist, one piece caught my eye though. entitled “Evolution in the Cornbelt“, by Conor Gearin. The story focuses on the Prairie Deer Mouse (Peromyscus maniculatus bairdii), a common little fellow from the Great Plains that feeds on the tiny seeds of grasses and weeds in the prairies.

Researchers at Iowa State and Purdue University were curious how a species so adapted to life in the Great Plains has been able to thrive, given that >99% of the original tallgrass prairie in the region has been plowed under, converted to agriculture, urban land, or other man-made land uses. The grass and weed seeds the Prairie Deer Mouse had historically fed on were much more sparsely distributed than they were 200 years ago, yet the species is still quite common.  They started field work to assess the distribution of the nice, including setting up artificial nest boxes that the mice could use for habitation and food storage.  The results astounded the scientists.

Prior to beginning the work, it was assumed that deer mice populations would be the highest in “edge” habitat, areas such as grassy ditches, fencelines, or other “boundary” conditions where remnants of their traditional food sources may still be found.  However, they quickly found that the highest populations of deer mice were often right in the middle of very large corn and soybean fields, far from any traditional food source.  Clearly, Prairie Deer Mice had adapted to an agricultural setting, and were feeding on man-raised grains and pulses. The question was, how could a tiny mouse that was so well adapted to eating tiny grass and weed seeds shift gears and start feeding on corn and soybeans?

The researchers found historical deer mice in historical museums, creatures that had been preserved with taxidermy. Anatomical comparisons with Prairie Deer Mice from today found some stark differences.  The older specimens were well adapted to feeding on tiny seeds, with small mandibles and jaws that didn’t open very far.  The modern specimens had 1) significantly longer lower mandibles, 2) structural changes that allowed their mouths to open wider, and 3) larger upper mandibles. Accompanying the larger mandibles were more robust “hardware” for linking bone to muscle, with beefed up jaw muscles that enabled the tiny mice to feed on much larger food items than they had historically.

In the blink of an eye, geologically speaking, Prairie Deer Mice had shown measurable, obvious evolutionary adaptation in response to their new environment and food sources.  The researchers found high densities of deer mice in the middle of corn and soybean fields.  Some inevitably will succumb to the mechanical tools humans use to turn and manipulate the soil, but with such a rich, dense, bountiful food source, the mice had quickly evolved to fill the new ecological niche and feed on corn and soybean waste.

For a scientist like myself, I’m completely dumbfounded by the sheer ignorance of those who doubt science…who doubt climate change is real…who doubt in evolution.  The actual empirical evidence is overwhelming, conclusive, and “in-your-face”, for those who bother to open their eyes to the world around them. It’s a fascinating story, and the writer (Conor Gearin) did a great job not only summarizing the research, but telling it in a true story-teller’s fashion.  To me, this is exactly the kind of story, and writing style, that could perhaps help to turn the tide against the anti-science wave that seems to be cresting in the U.S. right now. Great story, and The New Territory really looks like a publication that’s worth subscribing to or picking up if you get a chance.

Grand River National Grasslands, Harding County, South Dakota

Expansive grasslands of the Grand River National Grasslands, in Harding County, in far northwestern South Dakota. Grassland habitat like this is greatly reduced in the Great Plains. However, that doesn’t seem to be a problem for one species, the Prairie Deer Mouse, who evidently can do quite well without an actual “prairie”.

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