...declines in the kingsnake populations have occurred and, with far fewer predators, the copperhead populations have increased.
Lawrence, KS (PRWEB) February 20, 2014
Herpetologica – The ecosystems that shape our planet are a delicate balance of water, mineral, plant, and animal life, and a large part of what maintains the natural order is the predator–prey relationship. Unfortunately, when we see a shift begin to occur, and a particular species population starts to thin, it can be nearly impossible to predict how an ecosystem will react to that change, especially if another species becomes abundant.
Currently, in the southeastern United States, a decrease of the once-prevalent kingsnake populations and an increase in the populations of copperhead snake are being observed. The article “Copperheads are Common when Kingsnakes are not: Relationships between the Abundances of a Predator and One of Their Prey,” in the journal Herpetologica, hypothesizes that as kingsnakes become fewer, more room is available for copperheads to populate, because copperheads are common prey for the kingsnake. These changes represent obvious shifts within the trophic web of the ecosystem, and the fallout has yet to be determined.
The authors conducted a study to determine the changes in population sizes of the two species by collecting data from snake surveys that have been ongoing for 2 to 7 years throughout the southeastern United States. From 377 traps deployed in an array of habitats, the authors recorded captures of 299 kingsnakes and 2,012 copperheads. Their analyses of the data indicate that declines in the kingsnake populations have occurred and, with far fewer predators, the copperhead populations have increased.
In their paper, the authors show how snakes can effectively regulate the populations of other snake species and discuss the consequences of reduced snake population sizes. Because of the elusive nature of snakes coupled with the general lack of long-term demography data, however, the authors were unable to quantify any correlation between habitat change and snake populations. The demographic shift in the ecosystems across the southeastern United States will have interesting future effects and, because snake populations are decreasing worldwide, it may also give a glimpse into similar happenings elsewhere.
Full text of the article, “Copperheads are Common when Kingsnakes are not: Relationships between the Abundances of a Predator and One of Their Prey,” Herpetologica, Vol. 70, No. 1, 2014, is available online.
Herpetologica is a quarterly journal of The Herpetologists' League, containing original research articles on the biology of amphibians and reptiles. The journal serves herpetologists, biologists, ecologists, conservationists, researchers, and others interested in furthering knowledge of the biology of amphibians and reptiles. To learn more about the society, please visit: http://www.herpetologistsleague.org.