Conservation management efforts attempting to decrease the effect of single-species overpopulation traditionally rely on biological control through predator introduction or human interventions such as culling. Joseph presented the concept of sport hunting as an effective tool for controlling the population of white-tailed deer (Odocoileus virginianus) in the United States, which the Illinois Department of Natural Resources states as one of the most effective deer management tools.
A male white-tailed deer, known as a buck.
There are currently an estimated 30 million deer in the USA, which under optimal conditions is expected to double every two years in the absence of population control mechanisms. Deer have become overpopulated in many areas of the USA, and are causing a broad range of social, economic and environmental issues. For example, 0.65% of cars in the USA have reported deer collision in their insurance claim, and the annual economic impact of deer collisions, habitat destruction and forest degradation due to overgrazing is estimated at $640 million in the thirteen most north-eastern states. The areal extent of deer overpopulation is expected to increase with the effect of global warming, a result of anthropogenic climate change, increasing the available optimal conditions for exponential population growth.
Rosa multiflora, now defined as a national pest
Despite being generalist species, deer exhibit a range of preferences within their diet. They preferentially graze on native shrubs and understory plants, such as red trillium (Trillium erectum), allowing the proliferation of non-native species into vacant ecological niches. The mutliflora rose (Rosa multiflora), originally introduced from Asia in the early 20th century, is now considered seriously invasive by US authorities. The effects caused by overgrazing often result in drastic changes in forest and grassland plant biodiversity, and consequently ecosystem dynamics are strongly influenced. The precedence for effective deer management is clear. So why should we consider sport hunting the best option for population control?
A buck pursued at night by a hunter in Central Texas
An estimated 10 million Americans spend over $6 billion annually obtaining the legal permits and licences to hunt deer. Consequently, hunting not only reduces the economic and environmental costs associated with species overpopulation, it also provides a steady income for governmental organisations to utilise in a broad range of conservation efforts. For example, the Federal Aid in Wildlife Restoration Act contributes over $370 million annually, estimated to have contributed a cumulative £7.2 billion to US conservation efforts since its inception. This money is applied to habitat protection and repair from deer overgrazing.
Encouraging deer sport hunting seems like a well-rounded solution to this crisis.
Biological control may be considered as a means of white-tailed deer population management. The natural predators of deer are wolves, coyotes, and mountain lions, the populations of which have been largely wiped out by anthropogenic interference. In some cases, such as in Yellowstone National Park, predator reintroduction has been a success. However due to unprecedented urban expansion throughout most of the north-eastern, western and southern states, this was deemed unachievable on a nationwide scale. Another option may be an all-out deer cull, however this may reduce roaming deer populations too far, resulting in less hunting during the season and ultimately less hunting permits purchased. Increasing the legal hunting season could be seen as the most viable option, providing mutually beneficial outcomes for the area’s ecology and economy.
In summary, deer overpopulation presents a broad range of socio-economic and environmental challenges. Hunting is in important part of government income, and the proceeds may be used in habitat protection or restoration. It is for these reasons that recreational hunting should be considered a valuable conservation tool.
By Adam Searle