Culling - a word for selective, legal hunting - has been the focus of wildlife authorities for years in their mission to reduce the wild animal population too close to people or livestock. Advocates view the practice as a way of reducing poaching and controlling hunters who would otherwise conduct illegal hunting activities.

"The harvesting of wildlife on refuges is carefully regulated to ensure an equilibrium between population levels and wildlife habitat," according to the U.S. Fish and Wildlife Service (FWS).

However, a new study has revealed that using legal hunting practices such as culling might not always be an effective strategy.

"For about 100 years, the status quo wildlife management assumption is that hunting, trapping, and angling are good conservations strategies," said Adrian Treves of the University of Wisconsin-Madison and senior author of the study. "There is no evidence to suggest that poachers are going to refrain just because there is a legal recourse."

The study, titled "Blood does not buy goodwill: allowing culling increases poaching of a large carnivore," reveals that culling can increase poaching in regions where carnivores are prey.

The team studied wolves in Michigan and Wisconsin between the years 1995 and 2012. During this period, the animals were not on the U.S. Endangered Species list in both states and culling was periodically allowed.

The data revealed that although there was overall growth in the wolf populations, this growth curbed by approximately four percent during the years when culling occurred. Furthermore, wolf populations grew by 12 percent in the years when hunting was permitted, compared to the 16 percent growth observed when wolves were left alone.

"When the government kills a protected species, the perceived value of each individual of that species may decline; so liberalizing wolf culling may have sent a negative message about the value of wolves or acceptability of poaching," the researchers wrote.

"Culling sort of makes it somewhat permissible to shoot a wolf," said Matt Bishop, an attorney at the Western Environmental Law Center. "So it's not that much more of a step to shoot one illegally. It makes it more taboo to shoot it if you can't shoot it at all."

The findings were published in the May 11 issue of the Proceedings of the Royal Society B: Biological Sciences.