Tuesday, July 31, 2012

Copperhead Clusters

Copperheads x 4 -Click to enlarge
I received a call from our good friend Sheila describing an invasion of copperheads around her walk between her front door and her parked car.  She had been forced to kill 14 over three days.  Her neighbor a quarter mile away has killed 12 copperheads in her front yard as well. She shares our love of nature in the wild and called me for absolution of her sin.

She first encountered the copperheads when getting out of her car shortly after dark.  There were four within a circle of her flashlight.  This was on the way to the front door 30 feet away, the path her dog and cat use for their nightly duties.  For this reason she was forced to kill them.  This was the first of several sightings of multiple copperheads in the same area over the next week

The next night she was out watering her trees next to the car when she saw a copperhead 8 feet up in the tree.  It was slowly patrolling the trunk not disturbed by her flashlight beam.  You can see it had no difficulty traveling around the trunk.  She took this movie and these pictures.  She has continued to find copperheads in this 100 foot radius from her front door including another one staring at her from a low branch of her redbud tree.

Sheila's house is up on the ridge above Bull Creek, a pretty spot with a view down a valley out the back and a level front yard with mature trees and mowed grass.  There are several piles of wood and downed branches gathered away from the house which would provide harborage both for snakes and their rodent prey.

A famous gathering of snakes, predominately copperheads, occurred just five miles from us at Pine Ridge Church in 1965, leading to Chadwick becoming the "Copperhead Capitol," the subject of the next blog.

Reports of mid-summer clusters or irruptions of copperheads are not just from Bull Creek.  A mid-summer 2005 gathering of 100 copperheads under a cedar tree in Marion County, Arkansas was investigated by an Arkansas State University zoologist with no apparent cause found.   Recent accounts tell of gatherings occurring in Southwest Missouri and Texas.  In summer of 2011 a man in Georgia reported 30 copperheads in his yard.

Back to Bull Creek
This irruptions would be expected in fall when copperheads gather together for hibernation. I have contacted Dr. Stan Trauth,  Professor of Zoology at Arkansas State University who has been studying this common phenomona of mid-summer copperhead gatherings for years.  He confirms that no one knows the reasons these occur.

As you might guess there is no shortage of theories.  In 1965, the Pine Ridge Church irruption of copperheads was explained as "Imps of Satan, sent by the Devil to disrupt the services of the Lord."*  Another source links the 2005 event in Northwest Arkansas to religious reasons also, as it was near Mount Nebo, and Magazine Mountain "which is the possible resting-place of the Ark of the Covenant."

Copperheads are very heat tolerant and usually forage at night during the summer.  Factors commonly mentioned in reports of mid-summer copperhead clusters are heat and dryness.  These reports are from around human dwellings where watering occurs.  Moisture could serve as a draw for insects and mammals, creating a magnet for copperheads.  Rural dwellings frequently have woodpiles and piles of yard waste and limbs, offering harborage for rodents and copperheads.  Another theory comes from a very detailed scientific website, herpsofarkansas.com.
"Human encounters with this snake become more commonplace during the very hottest part of the summer for two primary reasons. One reason is that this is the mating season and males are moving around much more in search of females. The second reason is that it appears this is a time of year when copperheads become increasingly more active in their pursuit of prey. In fact, they may even congregate in areas where large numbers of cicadas are emerging; even pursuing them into trees! Dusk and dawn seems to be when these snakes are on the move the most."  Article link
July cicada
Sheila's yard of mowed grass and mature native trees is a perfect place for cicadas to live out their larval period. She has been seeing cicada clinging to her tree trunks.  They present a juicy treat for a copperhead, even if it has to climb to find them.

What to do?
Killing a snake would be my last resort unless it is around a dwelling where it is a threat to life and property.  However sometimes there is only one letter difference between "loving" and "living" when it comes to rural living.  We are moving into animals' territories as some of them (deer) are moving into our cities.

There is a gradient in what we can tolerate.  At our house on Bull Creek we catch spiders and move them out side... except for brown recluse which die suddenly as do red wasps.  Wood rats are fine in nature but in the house, not so much.  The risk to me in catching and transporting a copperhead out of my yard far outweighs the benefit to nature.

Prevention is the best answer.  Making your space less hospitable to rodents and other food sources will decrease the likelihood of finding copperheads next year.
  • Remove trash, yard waste piles and other harborage
  • Keep large firewood piles away from the house
  • Avoid leaving potential food sources for rodents such as pet food
  • Eliminate standing water around the yard
  • Seal crawl spaces and access to outbuildings
  • Trap rodents to eliminate a food source
  • Trim back tall grass and bushes that could hide snakes
This corner of Missouri and Arkansas seems to be blessed with high numbers of copperheads and Ozark natives have always had a close if not always welcomed relationship with snakes.  Silas Turnbo collected Ozark stories around the turn of the century including many revolving around snakes.  The preeminent historian on Ozark folk lore, Vance Randolph, collected many Ozark superstitions about snakes which I have compiled at this site.

2017 Update:
Quote from John Miller of the Missouri Department of Conservation:
""They eat mostly rodents, but copperheads also love to eat cicadas when they just emerge from the ground," Miller said. "Sometimes a property owner might see several copperheads at one time, but they're there to eat the cicadas, which we like to call the 'M&Ms of the insect world.'"
Now play the video of the copperhead in the tree again and listen to the cicada chorus!  That likely explains at least this cluster.

* See the Pine Ridge Church story on next blog.
Here is a Copperhead Safety lesson.

Note:  If you follow the blog and read the "Tree Frog" entry, click on this to see corrections thanks to Dr. Trauth, an expert on Amphibians and Reptiles of Arkansas.

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