Drama on Damon Run: Mink Monitoring Part 3

This story is part of an ongoing wildlife monitoring project along a tributary of Salt Creek, Damon Run,  that meanders through Meadowbrook Nature Preserve. Check out Part 1 and Part 2 to catch up!

 

By: Jim Haniford

Nothing prepared me for winter through the lens of the trail camera.  Once Sarah fine-tuned its sensitivity, I learned you can literally watch the woods go to sleep.  They darken incrementally as the sun sets.  You notice the few brittle leaves still clinging to autumn on the end of a branch.  They twitch between frames, dancing in a lonesome breeze.  You watch the skeletal silhouettes of trees reappear as the sun rescues the forest from the icy talons of another lingering midnight.

Soon the camera registers color again:  muted browns and faded greens and shards of light blue sky peeking between faraway branches.  Morning is a visual symphony.  Sunlight glints off snow-caked limbs and the creek sparkles and there are really no adequate words for it.

Yet for all their beauty, the winter months can be unimaginably cruel, even in our temperate Midwestern zone.  Food becomes scarcer, and keeping warm burns a lot of energy.  The daily fight for survival accelerates.  I’ve come across some pretty grim scenes out here in the wintertime.

I don’t know if you’d call it a “talent,” but I have a knack for stumbling across carcasses.  I’m like an unintentional bloodhound.  Maybe my spirit animal really is a Turkey Vulture.  I come across raccoons the most.  I find them in odd poses and strange places.  Two years ago, I found one dead in a tree.

So it shouldn’t have come as a surprise when I found one laying near the trail cam when I came to check it the day after Christmas.  But it did, because what are the odds that it would happen right where we had a camera set up?  I felt a sadness for the little creature as it lay there, its fur carpeted by a dusting of fresh snow.  Based on some observations I was able to make, I guessed it died of disease.  Maybe distemper.  Unfortunately, that’s relatively common with raccoons.  Its lips were pulled back in a frozen grimace, revealing two rows of clean, white teeth.

As bad as I felt for the raccoon, my curiosity was piqued.  It had fallen about eight feet to the left of the mink’s den.  I wasn’t sure if it was within range of the camera, but it had to be close.  That meant there was a good chance I’d see its final moments.  That might answer some questions.

I also knew that the body would attract scavengers, luring them right into frame.  We’d be able to watch the whole process.  Often with projects like these, where you’re monitoring the behavior of one species at a particular site, other opportunities for study present themselves.  I like to think of them as “side missions.”  Sometimes you’re able to observe the activity of other species that can directly affect your original subject or its surroundings.  And sometimes it’s something totally unrelated, but no less worthy of your attention.  For this side mission, we’d be able to study how scavengers benefit the ecosystem by helping to keep their habitats clean.  All while keeping an eye out for Mr. Mustelid.

I figured opossums would come sniffing around the carrion.  They’re consummate scavengers.  I observed one working a dead raccoon years ago.  What else might show up?  Maybe some crows, I supposed.  Then I thought about coyotes and got really excited.  They’ve long held a place in my heart.  Coyotes are scavengers, too.  But they’re also keen hunters, I reminded myself.  They’ll poach muskrat from their dens, so what would stop them from nosing around for the mink?  I’d sure hate for us to document the mink’s presence only to watch it be devoured soon after.  I’d love to catch some shots of coyotes in action, but not at that price.

Ultimately, this project is a labor of science.  True, we’re not working under laboratory conditions or following the strictest protocol.  But we should at least try to avoid influencing the wildlife we’re observing.  Our interactions should be reserved, our interference minimal.  That’s not always easy.  It’d be a different story if the issue was a manmade one:  a discarded food wrapper laying outside the mink’s den, for example, or an unleashed dog trying to dig its way in.  I’d have picked up the litter or chased the dog.  Otherwise, the best practice is to let nature take its course.  Sarah agreed that we should leave the raccoon where it was.

So I turned back to the camera, took out the SD card, and downloaded the images on it.  I stood ankle-deep in the creek, waiting, the ambient sound of the forest muffled under winter’s blanket.  In those moments, I try to be as mindful of my surroundings as I’m able.  The swirling history of eons narrated themselves in a liquid murmur below me.  Every now and then a titmouse wove its lonesome song through the brittle air.

After a few minutes, my phone downloaded the last photo.  I slid the card back into the trail cam, closed the cover, and glanced over at the raccoon.  I could still see its teeth.  Then I climbed back up the streambank.  Standing at its edge, I ran my gaze over the front of the den.  Nothing seemed out of place.  I made my way back up the trail under a sky the color of concrete.

Back at home, I reviewed the images we’d collected on our TV.  The bigger the screen, the easier it is to make out the shadowy figures that appear in the photos.  My wife and I settled in and started clicking through the image files, looking for any clue that might point to the raccoon’s cause of death.

With projects like these, where you’re monitoring the behavior of one species at a particular site, other opportunities for study present themselves.  I like to think of them as “side missions.”

In the early morning hours of December 23^rd, a raccoon showed up directly in front of the camera.  It seemed to be heading toward the left side of the frame, the same area where I later found the carcass.  This was shown in two consecutive images.  I was slightly jarred by the third, in which the raccoon was now standing directly in front of the lens, facing the opposite direction.  Its head was tilted skyward and it seemed to be looking at something up in the air.  Then it was gone, completely out of frame.  The sequence had taken a little under two minutes in real time.  If that was the same raccoon that now lay across the creek bed, we may have just watched its final moments.

Nothing else tripped the camera until fourteen hours later, just after the sun went down again.  The mink poked its head out of its den for a moment, its eyes shining eerily in the infrared’s beam.  Like the first mustelid image we captured, the quality of the image wasn’t great, but it was more than enough to identify the mammal.  The only other images on the camera showed an opossum that came around the next day.

We could see that the camera’s horizontal range didn’t extend far enough to show the raccoon’s body.  It lay just beyond the edge of the view.  The following week when I hiked back down to check the trail cam, I turned the camera enough to cover it.  It took another visit or two before I’d adjusted the angle enough that the lens fully covered both the raccoon and the den at the opposite side of the frame.

At home once again, my wife and I weren’t prepared for all the activity the camera had captured over the past week.  Usually about ten images or so were saved on the card over the course of a week.  This time there were about two hundred.  Sarah had adjusted the camera’s sensitivity to motion after an experiment with the video function produced poor results, so that had something to do with it.  But the sheer volume of activity at the site had increased, owing almost completely to the presence of the carcass.

By far the most frequent visitor was the ‘possum.  Starting with a few timid investigations, the ‘possum was soon returning to feed on the raccoon numerous times in a night, staying for longer periods each time.  We watched as its head plunged into the dead animal’s abdomen again and again.

Before long another ‘possum showed up.  They didn’t share the plunder right away.  One would adopt an aggressive posture and hiss, baring endless rows of jagged teeth, until the other backed down.  The newcomer was huge compared to the original ‘possum.  It was longer and looked quite a bit heavier.  So stocky, in fact, was its body that it almost appeared cylindrical, without a neck.  In addition, its fur was very fluffy and white.  It looked pristine in the scant light enhanced by the camera’s night shot, like the fresh snow that carpeted the ravine.  We could usually differentiate between the two ‘possums based on the differences in their appearance.

The days wore on down at the creek.  By now it was January and the dead raccoon was tantamount to an ongoing buffet.  There was a sizeable hole torn into its abdomen, and most of its intestines had been gouged out.  The guts are always the scavengers’ choice cuts, the tissue soft and full of nutrients.  At this point the raccoon functioned as a sort of “carrion freezer.” The ‘possums visited it constantly and at all hours of the night.  We went from collecting two hundred photos in a week to over nine hundred.  Our weekly review had come to reflect a tale of almost epic proportion.

More raccoons showed up.  At first there was only one.  It would attempt to feed on its fallen comrade.  I hadn’t even thought about the prospect of cannibalism, especially not by a raccoon.  This behavior would last until one of the possums returned to feed.  Then there’d be a showdown, and from what we could tell, the raccoon would be forced to back down.

 

 

Finally it called in reinforcements.  We watched as a “gang” of raccoons arrived on the scene, dominated by a huge, mean-looking individual.  He looked grizzled, like some “old granddaddy raccoon” of the forest.  But even they couldn’t cow the hungry marsupials into submission.  I’d assume they ate their fill, too, but I don’t think they were able to manage it while the possums were around.

 

 

Next time I hiked down to the trail cam only to find the hindquarters of the raccoon laying on the rocks of the creek bed.  They were situated roughly where the whole body had lain a week before.  I couldn’t imagine where the rest of it went.  And I looked.  I scoured that whole rocky stretch, and the banks surrounding it.

The only thing I found was a shard of bone up above the creek.  The rounded edge of a scapula, or shoulder blade, from the looks of it.  Something relatively large had obviously sat there to eat, melting the snow around it in a wet, circular patch.  I felt sure I’d find the telltale pawprints of a canid:  a coyote or even a fox, which will also feed on carrion from time to time.  But there were no tracks leading away from the melted patch that I could discern.  Out here, I couldn’t see anything but a coyote having the jaw, neck, and shoulder strength to tear the raccoon in half like that.  It may have been dead, but it was far from decaying.  In fact, it was frozen solid.  Once again, we’d have to rely on the trail cam to tell us the truth.

Back at home, we couldn’t wait to see what it revealed.  As we clicked through the nine hundred thirty-eight more images the camera had collected over the past week, our curiosity turned to amazement.  We watched as the two ‘possums, the big and the little one, dragged the upper half of the raccoon into full view before the camera.  So apparently, ‘possum were powerful enough to pull it off.  The smaller one stayed, gnawing and yanking at the frozen meat.

One of the raccoons came back, sniffing around the corpse, looking to get another piece for itself.  The possum bared its teeth again and again as the raccoon pushed its luck.  This resulted in some pretty dramatic photographs, as you can see here.  Somehow, though, the two avoided a fight, and the raccoon was forced to move on.

 

 

 

Throughout that whole ordeal, the other ‘possum had watched from the safety of the overhanging bank.  It lurked below the dangling roots in the wet sand and soil, just outside the mink’s den.  I’d noticed it spending more and more time there, and it made me uneasy.  I hoped it wouldn’t disturb our mink.  The mustelid was still the primary focus of our campaign, after all.

 

We’d have to rely on the trail cam to tell us the truth.

Eventually, the dead raccoon was completely devoured.  Bones and fur are about all that are left now:  back legs and hips and probably a few vertebrae.  They’ll likely be scattered the next time the creek rises, to be lodged in the rocks along the banks or in a bottleneck of fallen branches downstream.

The whole process had lasted a little less than a month.  But I learned an awful lot in those few weeks about the behavior of scavengers- especially ‘possums- and how they go about their business.  The chain of events would have been similar in the summertime, I’d imagine, but the timeframe would have been much, much shorter.  Higher temperatures and the presence of insects would have sped the process along.

Things down at the den are returning to normal now.  Last week the trail cam took a hundred thirty-eight photographs, a far cry from nine hundred.  Winter’s a cruel season.  Many species have grown accustomed to life in these colder months by taking advantage of any gift that fate delivers, including a free meal.   In the wild, nothing goes to waste, and nothing sits around for very long.  This is the scavenger’s creed.  Left to its own devices, an ecosystem can keep itself clean and healthy.  It’s a principle we can borrow from wild habitats and put to use in our own.  At the end of the day, they’re still one and the same.