Friday, May 25, 2018

Four Minutes with the Weasels

With the return of the long-tailed weasel to Somme, the ecosystem may come more into balance. See below for photographs of six of them. Six? That may seem like an unreasonably high number, but wait til you see!
Weasels are predators we have often talked about – and so much wished for[1]. They eat voles. Somme's vole numbers are so high that we have to work unnaturally hard to keep the little rodents from extirpating rare plant species[2].

This adventure started on the evening of Sunday, May 20th, as I made an apparently minor decision. We had been trying to finish up many small projects and had a purple plastic sled hauling various equipment. The light began to fade; we were going to need some of this gear the next day and decided not to lug it back to the car. I folded my old raincoat over the stuff that needed to stay dry, then covered all with the sled, and hiked out happy and light. 

May 21 turned out to feature a horrendous, most-of-the-day rain storm. I didn’t head back until the rain stopped in early evening. How wet would my stuff be, after all that? When I turned over the sled, the raincoat looked mostly dry. I picked it up and hung it on a stump. As I did, a small animal shot out of it – as a blur – and disappeared into a hollow log. But within seconds it was back. In fact, it was so fast and so everywhere, I felt almost dazed. It was in front of me, behind me, within inches from my feet. Utterly unafraid. So quick it was hard for my eyes to follow. 

I felt surrounded, enveloped, and confused. 
So everywhere at once, the weasel seemed like a spirit from another world.
In all my photos, she is more or less a blur.
Then I saw what she was after.

Mama weasel retrieving baby weasel
When I picked up the coat, I dumped babies all around my feet. The smart little mama had figured out that my old Goretex coat and purple sled, compared to a leaky log, had made a better shelter from the storm. But now, thanks to me, she had a mess to clean up.  
In this photo, mama blur is hauling baby blur back to their hollow log den
while three others wait by the little log, above right. 
Twenty seconds later, she's back for the next kit. 
Eyes closed and helpless, a baby waits.
Eight seconds after that last photo is taken, she's back. 
One second after that last photo, she and her mouthful are off.
My next two photo attempts miss her entirely, as did many earlier ones. About half the time, I photographed where she had been. But next, I take a different kind of photo.

Now she's racing around, not finding anything. She's missing one. Where is it?
I lose track of her. Then my raincoat starts jumping around.
She's in the hood ... going up and down the sleeves ... in the lining, apparently.
The whole coat vibrates. Where is that last kit?
And then she's gone. Must have retrieved it. The adventure is over - at least the personal part of it. The precision of iPhoto revealed that it took her about 20 seconds to pick up each kit, install it back in her hollow log, and return to grab the next little precious. 
Here's the den she lugged the kits to. She used the hole to take quick looks out.
But the actual entrance is through the crack, which widens a bit under those geranium leaves.
My whole blessed encounter with the long-tailed weasel was completed in about four minutes. Actually, the photographic part of it, as documented by time stamps, lasted from 7:34:11 PM to 7:37:39 PM. That’s 3 minutes and 28 seconds. But I felt like I shared a brief eternity with them.
 Since then, I’ve studied our two Illinois weasels – the long-tailed[3], which this one was – and the least[4], which we can also hope for. A better prey-predator balance means a happier ecosystem. 
The ecosystem here is open oak woods that's been under gradual restoration for decades.  Before stewardship, this area was so dark from invasive trees that the ground was bare dirt. For that reason it had few voles, mice, or rabbits (and of course few birds, butterflies, little of most other nature). 
Habitat looking northwest from den. Huge old bur and white oaks have mostly not reproduced (because of excessive shade) for decades. Now they're starting to have seedlings and saplings, mostly not in their own shade, but in woodland meadows that have replaced what were "pure" stands of invaders. It may take many more decades (or centuries?) before this woods fully recovers its natural patch dynamics of thickets, meadows, and canopy tree reproduction.
So we celebrate each returning feature and species as we can.
Welcome back weasels. We hope you're here for good. 
Endnotes
[1]Returned? How do we know they weren’t already here? Well, we don’t for scientific sure. But long-tailed weasels are curious. If you’re out in an ecosystem much of the day, week after week, decade after decade, you tend to see them pop up, give you a look, disappear, and then pop up somewhere else to look again.

Our region's two weasel species are both ferocious hunters that regularly kill rabbits, that are ten times their weight. But their principal food is voles and mice. Weasels have high metabolisms and eat 40% of their weight per day. The least weasel is principally an animal of grasslands. Long-tailed weasels hunt in prairies, savannas, and open woodlands.


[2]Voles (or "meadow mice") are the commonest animal in the grassland and also common (with white-footed mice) in savannas and open woodlands. We find that voles sometimes cut most or all of populations of such rare plants as prairie white-fringed orchid, eared false foxglove, prairie lily, and prairie gentian. Some of these populations revive if we cage plants individually from the voles, but it's humanly possible to do only so much of that.
These vole cuttings are in every square foot of grassland after burns done when the ground was moist.
Voles have a huge impact on every square foot of grassland, which is natural and good,
as long as predation maintains some level of balance. 

Why do we care if some species are wiped out? This blog has published many responses to that question. But certain scientists (with little vision) have recently written provocative pieces saying, in various forms, "Who cares? Extinction is natural." Good responses to those poorly thought-out challenges were recently published by Carl Sarfina.

[3]Long-tailed weasels evolved in North America about two million years ago, from a larger species. Our current, new, smaller species is thought to have evolved to take advantage of the bounty of small rodents simultaneously evolving on the prairie, now five million years old as a new ecosystem type. So it took the long-tailed about 3 million years to catch up. It is rash of our culture to lightly dispose of ecosystems, relationships, and gene pools that took millions of years to develop.

[4]We hope the least weasel returns to the Somme preserves too. But we'd be less likely to see it. They're enough smaller that they spend almost all their time under the grass prowling through vole tunnels. Indeed, they could already be here. But the superabundance of voles makes us doubt it. 

Thanks
For proofing and improvements to Kathy Garness and Eriko Kojima.
Thanks to you for any comments.