Copperheads vs. Cicadas - July 2014

Copperhead Research Project

McCreary County Site, Kentucky

Copperhead swallowing a cicada nymph

I was contacted by a Raymond Little for more information on a cicada emergence and a large congregation of Northern Copperheads that seemed to be attracted to the emergence of the annual cicada. He was conducting a research project on the Copperheads and wanted to learn more about the life cycle of the cicada to understand more of what he was observing.
 

Raymond Little writes: 

"I have documented several sites with large numbers of copperheads. By large numbers I mean like around 100 at one site last summer. I have caught 20 plus in less than an hour and a half. All the sites are wooded areas bordering relatively open mowed grass. The snakes are actively seeking and feeding on cicada nymphs and adults and this seems to be their only purpose at these sites. I have regularly documented them climbing trees to consume cicadas. So, I am trying to determine why so many snakes are at these small areas." 

He catches the Copperheads and measures, weighs and sexes them and also "pit tags (1)" them. This is part of an on-going research study she is participating in.

Box of captured Copperheads. You can see by this photo where they get their name.

Tibicen Linnei emerging

Tibicen chloromera teneral

His theory is, depending what he learns about the cicadas, is that 

"the snakes travel to these sites from some distance just to feed on the cicadas. Otherwise it would just seem impossible for these small areas to support that number of copperheads. My new site this year has historically had large numbers of copperheads killed there. I caught 17 last week in a little over an hour. They are almost always no more than three feet into the wood-line. They follow the wood-line along the same paths like its a fence. This new site has more trees in the open area so, I have caught several leaving the wood-line to the base of these trees." 

He goes on to say "it has been well documented that copperheads feed on cicadas but, the arboreal activity associated with feeding hasn't been documented in the Northern Copperhead until now". He has found the snakes as high as 9 feet up into the trees seeking out nymphs and emerging cicada! "The aggregation activity is the most interesting to me," he said.

Copperhead climbing a tree to get the nymph

Copperhead climbing a tree to get the cicada

Little feels "they clearly seem to follow scent trails from the cicadas". He said he caught as many as four snakes going up the same tree for a single cicada. "I have seen them feed more in trees than on the ground. Usually nymphs with a couple of adults. That was interesting considering the nymphs potential to injure the snakes. I have seen one leave a nice gash on one of the snakes mouths. The late Roger Conant found a dead copperhead once with a cicada emerging out the side of the snake."

Little sent me some photos of the Copperheads, cicada and nymphs. Elias Bonaros and Bill Reynolds, two cicada enthusiasts, were able to help identify two cicada species for Little, the Tibicen tibicen (chloromera) and the Tibicen Linnei. Elias Bonaros made another interesting observation from the photos. It appeared that the Copperheads were swallowing the cicada nymphs and adults whole without envenomating them. This would make sense from the earlier observation recorded by Roger Conant, of the cicada nymph emerging out of the side of a snake!

Copperhead swallowing a cicada nymph whole

If anyone has seen similar activity please contact Raymond Little to let him know! Thank You!

**Photos taken by Raymond Little

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1. Pit Tag: The tag is about the size of a grain of wild rice, consists of a coded microchip encased in glass. Researchers inject the tag into a snake's body cavity through a syringe poked between its lower belly scales. This procedure causes no known discomfort. When they recapture the snake researchers use a decoder to read the individual reptile's unique identification number. "Pit Tag Fact Sheet" <http://srel.uga.edu/outreach/factsheet/pittag.html>