Gumweed, Darklings and Killer Mice

It’s been a busy several weeks. After I came home from the conference in San Diego, I spent a weekend at home alone (AW and the Trifecta were visiting family in New Jersey) racing and getting ready for my next trip. Monday morning before heading to the airport I wanted to sneak in a quick ride. Lacking time to drive up one of the canyons, and wanting to ride the mtn bike, I rode the Shoreline Trail for the first time in 2 months.

Side Note: The race was the Tour de Park City, a race I’ve shined in the last 2 years. This year it sucked for me, which is par for the course for me racing this year and which is in turn more properly the subject of a long whiny tangent (which I will probably not do, because really, who likes whining?) Coming into the feed zone at mile 122 I was distracted by an RV passing on the left, and while reaching for a bottle accidentally got a finger in the spokes*. On the bright side I’ll have material for a post sometime on how fingernails grow. We shall return to this injury, the problem it presented the following week, and my mother’s ingenious solution, in the next post.

*Fortunately I race with full-finger gloves, and so couldn’t see the extent of the damage until after the finish line. The following morning I got to work on some overdue mtn bike maintenance, and I just want to point out what a phenomenal dick-dance it is to install grips with a massive bandage on your good hand…

I’ve been mtn biking a lot this summer, but riding practically everything except Shoreline. By late May, when trails up in Park City and Jeremy Ranch start opening up, I’m usually a bit tired of the open foothills, and drawn to the cool, shady forests that I can only ride in for 4 or 5 months of the year. So returning to Shoreline was a bit of a shock. Last time I rode it, it looked like this.

Last Monday, it looked like this.

Even though it was still early and cool, it just looked hot. The slopes were littered with wilted Balsamroot and Arnica leaves, the successive waves of yellow blooms long past. The Oak leaves, soft and lime green on my last ride, were dark and leathery. Everything seemed dry, brittle, dusty and brown. With still several weeks of summer left, I felt a bit deflated, that another season had passed, that I’d missed a good part of the explosive waves of summer blooms, and was now riding through the leftovers and wreckage of the party I’d somehow missed.

But “missed” is all relative, isn’t it? I pay as much or more attention to the blooms, and the natural world in general, as any mtn biker I know, but what has slowly dawned on me over the 3 summers on this project is that I’ll never get the sense of capturing it all. There will always be a million things I don’t get a chance to check out or even notice, and somehow that’s both inspiring and disappointing at the same time.

Of course stuff is still happening throughout the summer, and once I got past the surprise, wistfulness and initial self-pity-party of the dry, brown foothills, I started to pay attention. Even now, so late and hot and dry in the living year, flowers are still blooming, and one of them, following the Balsamroots and Mules Ears and Arnicas, is yet another yellow composite. It’s small, bristly and tough-looking, but if you stop and look closely, it has a delicate beauty at least equal to that of its blooming-predecessor-cousins. It’s Curly Cup Gumweed, Grindelia squarrosa. Grindelia, or the Gumweeds, is a genus of more than 2 dozen species native to the New World. They’re called gumweeds because much of the plant feels sticky to the touch. G. squarrosa occurs throughout he Plains and Western States, and is common now in Northern Utah.

Gumweed is one of those plants that looks like a gnarly, bristly weed, and to a large extent it is. Gnarly and bristly, anyway; we’ll get to the “weed” part in a moment. Livestock and wildlife don’t eat it except as a last resort, not so much because it’s bristly, but more so because it’s packed with tannins and resins and such that make it difficult to stomach.

So, like other semi-arid “chemical warriors”, it tends to do well in dried-out, overgrazed pastures. But when you stop and check it out, it’s a beautiful flower. The little green spikes just below the ray flowers are phyllaries, and they overlap in an elegant pattern. A phyllary is a type of bract occurring just below the florescence of a composite flower (so only composites have them). If the flower were 3 or 4 times as big, it would make a wonderful addition to any bouquet at the local florist.

And it’s not quite clear that it’s technically weed. Many flower guides for the West will list Gumweed as “alien” or “invader”, and while that may be the case in Utah, it’s wrong to lump this plant together with Musk Thistle, Salsify, Houndwort and the horde of other common Eurasian invaders.

Side Note: I blogged about Yellow Salsify last year. In that post I mentioned Purple Salsify, which at the time I hadn’t yet spotted in Utah. I’ve potted it a couple of times this summer (pic right), both up around Pinebrook. Given Pinebrook’s track record as an importer of exotic “wildflower” species (Oxeye Daisy, Dame’s Rocket), I wonder if it’s a very recent addition to Northern Utah’s flora.

But Gumweed was first catalogued by Lewis and Clark on the high plains, long before it likely would’ve spread so far West via Euromerican introduction, and as best I can tell it seems that Gumweed is native East of the Rockies, but is an exotic to the West of them. So, like the Brown-Headed Cowbird, Gumweed appears to be a North American native that has greatly expanded its range as a result of human settlement and activity.

It’s interesting how some species- Dandelions, Rats, Raccoons, Cowbirds, feral Pigeons and perhaps Juniper- have thrived as a result of Euromerican settlement, while so many others have suffered. When you read that you may well have thought of something like Passenger Pigeons or Wolves or what-not, but I was actually thinking of roadkill. And when you read that, you may well have thought of deer or squirrels or what-not, but I was actually thinking of… beetles.

Foothill Massacre

This time of year the Shoreline trail- should you bother to look down- is fairly littered with corpses. Trampled in the dust, every couple dozen feet or so, you’re likely to spot a crumpled up black exoskeleton- the remains of a crushed Darkling Beetle, Eleodes obscurus.

Darklings are often called “stinkbugs” locally, for their defensive chemicals sprayed when threatened, but real Stinkbugs are something else altogether; they’re True Bugs, like Box Elder Bugs or Leafhoppers. Darklings are beetles, and have come about their “stink” defense completely independently*. They’re also called Pinacate Beetles or Stink Beetles, and oftentimes- just to make things- other Eleodes species are also called Darklings. In any case, I’ve always called E. obscurus Darkling Beetles, so that’s what I’m calling them here.

*Yes, yet anther way cool example of convergent evolution.

When threatened, Darklings don’t usually scuttle away under a rock. Instead, the stand stock still, and raise their butts up in the air. If the predator/threat doesn’t back off, it sprays the offender with a stinky chemical, skunk-like, out of its backside. As a result, when you stop to check out one of these guys, that’s how you usually see them- butt in the air.

Side Note: So far as I know, the spray isn’t harmful to us, though one source mentioned stinky fingers following handling. Just the same, I wouldn’t hold its butt up to your eye…

When Mice Go Bad

This chemical defense isn’t always effective. At least one predator, the Grasshopper Mouse, has developed a well-executed technique of rapidly grabbing the poor beetle and jamming its butt in the ground, where the spray squirts harmlessly. But it works well enough that the standard first defensive move of a threatened Darkling is to stop still and raise the rear tip of its abdomen.

Tangent: I usually try to stick to blogging about things I’ve actually come across, but the Grasshopper Mouse is so Phenomenally Way Cool I’m making an exception. Imagine if you took a mouse* and somehow suped it up. Gave it bigger, sharper teeth, stronger jaw muscles, longer fingers and claws for grasping and handling prey. And then this mouse ran around and actively hunted for a living, going after not just insects, but snakes, scorpions, lizards and even other mice (yikes!) A truly carnivorous mouse- wouldn’t that be way cool?

*Just so as to not give the wrong impression, the Grasshopper Mouse isn’t all that closely-related to the Common House Mouse, Mus musculus. So it’s not like some House Mouse just suddenly mutated and turned all evil and scary and everything.

That’s Onychomis torridus, the Grasshopper Mouse (pic left, not mine), which ranges throughout the Western US, down into Northern Mexico, and up into Southwest Canada. An aggressive carnivore, it stalks its prey stealthily, almost cat-like, and is apparently immune to the various venoms of many of its prey.

Wait- it gets better. O. torridus, like larger carnivores, actually marks territories by scent, and even, almost wolf or coyote-like, by “howling”! The Grasshopper Mouse sands on its hind legs (pic right, not mine) and makes a tiny, high-pitched call. Also, like larger carnivores, the young are taught to hunt by their parents, which is probably the reason that both parents participate in rearing young, unlike most other mice (or rodents in general).

O. torridus is One Cool Mouse, and has catapulted to the top of my Critters I’m Dying to Spot list.

It works well enough that supposedly* some number of similar-looking beetles actually mimic the behavior, stopping still and sticking their butts up in the air in response to threats (pic left, not mine**), even though they don’t have any chemicals to spray. You’re probably familiar with visual mimicry in the insect world- flies that look like bees, caterpillars whose hindquarters look like a snake’s head- but this is a neat example of behavioral mimicry, and it’s fascinating to think of the steps that might have brought it about, with beetles that happened to stick their butts in the air when frightened happening to survive a little more often to leave offspring behind, to whom they were likely to pass on any genetic disposition to butt-raising…

*I only found reference to this in one source- Field Guide to the Sandia Mountains, Robert Julyan & Mary Stuever, and was unable to find examples of the mimic-species.

** Actually used this photo last year, don’t have the source.

This Freeze-and-Prepare-to-Spray defense is probably the worst possible response to an approaching human foot or mtn bike tire. But feet on well-worn trails have been few and far between until the last several decades, and heavy mtn bike traffic non-existent until the last 2 or so. Darklings just haven’t had enough time to successfully evolve alternate defenses, and it’s questionable, given the vast, acreage of the adjoining trail-less hillsides, whether they ever would, or if the decimated populations would simply be continually replaced by immigrants from a few hundred yards away.

Tangent: This raises the whole fascinating issue on how roadkill might impact the evolution of various road-crossing critters over coming centuries (assuming cars are around that long.) There are far more roads than there are high-traffic singletracks, and one wonders what selection pressures automobile traffic is putting on critters like deer, rabbits, squirrels, coyotes and such. One would think (and this is pure conjecture here) that modest-brained critters would be likelier to evolve a general avoidance of asphalt more quickly than the ability to judge/gauge oncoming traffic, and so that the selected survival trait would not be so much a new ability or instinct for automobile-dodging as it would be effective isolation of populations within road-bounded “islands”, creating a new de facto “island biogeography”, like the desert-isolated mountain ranges of the Great Basin. Are Aberts Squirrel-style stories of speciation happening all around us right now as a result of roadkill?

In any case, I do my best to avoid running over Darklings. One beetle here or there certainly won’t make a difference in the big scheme of things, and they clearly don’t have much in the way of brains, or likely any kind of self-awareness. But the purpose-driven lives* of so many bugs convinces me that in their own, minimal consciousness kind of way, they “want” to live at least as much as I do, and if it turned out that there were some uber-aware, higher-state-of-consciousness thing/force in the world/universe that somehow perceived reality far above and beyond that which we’re aware of, I’d hope it wouldn’t just squash me out of laziness or convenience.

*Been itching to co-opt that term.

And to tell the truth, this year I find myself empathizing just a wee bit with the Darklings. For a long time, their tried and true schtick has served them well. But now, in recent decades, their world has suddenly changed and the tried and true is coming up short. This past year my world has changed somewhat, and while lots of that change has been good, the tried and true has come up short for me at times as well, at work and elsewhere. Sometimes this year I’ve wondered if I’m just stalled in the trail, butt up in the air. Need to do something about that.