Concept 3 Envirothon
Public Trust Doctrine of 1842: Conceptualized that natural resources are important in the lives of people, and that the public should have the opportunity to access these resources. This doctrine was formed after a number of species’ populations declined due to over-harvest.
The North American Model of Wildlife Management operates on seven principles:
Wildlife resources are a public trust.
Markets for game are eliminated.
Allocation of wildlife is by law.
Wildlife can be killed only for a legitimate purpose.
Wildlife is considered an international resource.
Science is the proper tool to discharge wildlife policy.
Democracy of hunting is standard.
In the United States and North Carolina, the Model is facing changes as society develops. Whereas science used to be the basis of policy making, much policy is now weighed on by the input of the public. Additionally, captive wildlife industries, such as the captive cervid (deer and elk) industry are changing the context of wildlife as a public resource.
The goals of wildlife management today focus primarily on the enhancement, protection, and conservation of the biodiversity of all fish and wildlife species, as opposed to individual game species.
Habitat fragmentation: Breaking up of habitat into smaller areas.
Large mammals, especially large carnivores, are notably affected by habitat fragmentation, because these mammals must have large ranges to meet their needs. Specialists are also negatively affected.
Many states are helping to mitigate habitat fragmentation by acquiring and conserving large tracts of habitat.
Wildlife managers have found that providing corridors (undisturbed strips of land which connects sections of the animals’ habitat) has worked successfully.
The most serious threat to birds (and many other animals) today is habitat destruction.
The commercial forests of today are often harvested at a young age and are incapable of supporting the diversity of birds that an old growth or mixed forest will support. The draining and destruction of wetlands has contributed to the loss of vital bird habitats.
Bioaccumulation is the buildup of a toxic chemical in the tissues of a single individual to a harmful level.
Ex. Ingestion of microplastics. Microplastics are not excreted like other waste, so they continue to accumulate in an individual’s fatty tissues and organs throughout their life. Therefore, the effects of the chemicals from microplastics will not be apparent until the individual is older.
Biomagnification: The result of chemicals transferring from lower trophic levels to higher trophic levels within a food web. This typically results in predators at higher trophic levels retaining larger concentrations of the chemical(s).
Ex. The use of the pesticide DDT (1940’s to the 1970’s). DDT contaminated runoff and made its way into aquatic food webs. Concentrations increased at each trophic level until the accumulated DDT was ingested by the Bald Eagle. High concentrations of DDT in Bald Eagles caused their population to decline.
‘Silent Spring’ by Rachel Carson brought attention to this issue.
Hunting with lead shot over water is no longer allowed. This is because the lead from the shot enters the food web.
Conservation: A term coined by naturalist Gifford Pinchot in 1907, means the wise use of a natural resource, while preservation means non-use of that resource.
Ex. A National Forest, which is carefully maintained as a timber resource.
Preservation: Set aside for recreation only.
Ex. A National Park.
The important principles of wise wildlife management stated by the North Carolina Wildlife Resources Commission are:
Wildlife management must be based on biological data.
The management of wildlife must include management of man because man’s activities affect wildlife.
Management means conservation, not preservation.
Management must be designed to benefit the entire biota (all the plants and animals in an environment) not just wildlife.
Many techniques are used to help protect and manage habitats as well as create new ones. Some of these techniques and tools include:
Food Plots or Wildlife Openings: Cleared areas of forest that are mowed or disked and planted with grasses and/or native plants to meet food and cover the needs of wildlife.
Buffer Strips: Strips of permanent vegetation in or around edges of fields, particularly near streams or rivers. There are various types of buffers including:
Filter Strips: Grass or other vegetation to trap sediment and pollutants before they reach waterways, also called “riparian buffers”
Corridors: Undisturbed strips of land, including vegetation and waterways that allow wildlife to move from one area of habitat to another
Field Borders: Grassed areas along the edges of crop fields.
Streamside Management Zones (SMZ): Buffer strips of vegetation along streams or around other water bodies like lakes and reservoirs, where forestry practices require special care to protect water quality.
Riparian Areas: Areas of vegetation along streams and rivers. These areas help remove pollutants before they enter the water body and provide corridors, cover, and food for wildlife. They also cool the water and provide dead leaves for the base food for macroinvertebrates.
Maintaining Edges: Practices used for creating and maintaining edge habitat include When harvesting trees, make irregular shaped cuts or indentations to increase the amount of edge. Plant vegetation or hedgerows to connect large, forested areas to serve as cover and travel lanes or corridors for wildlife. Mow to maintain grassy fields and various stages of succession. Individual homeowners and urban areas can landscape with shrubs and trees of various heights to provide vertical vegetation to increase wildlife habitat.
Significant progress has been made toward improving wildlife habitat. Forestry practices that address this include selective cutting, multiage stands, and seed tree cuts, all of which benefit wildlife.
It is also currently widespread practice to reforest or replant pine or conifer forests that are clear cut, which provides early successional habitat.
The Department of Agriculture offers curated programs that encourage and support farmers to conserve soil and water resources for the benefit of wildlife.
The Conservation Reserve Program, Conservation Reserve Enhancement Program, Wildlife Habitat Incentives Program, Wetlands Reserve Program, and Forest Stewardship Program are all examples.
Each of these programs helps create edges and ecosystems where more habitat requirements for a larger variety of species are met.
Habitat restoration or ecological restoration is another common form of habitat management.
Quite a few species are adapting to human-made environments, but numerous species are facing decline. For this reason, wildlife managers are calling on the public to help provide wildlife habitat through conservation landscaping.
Includes planting a variety of native vegetation, adding water features, and providing areas for resting and refuge, such as nest boxes and brush piles.
If a population becomes overabundant, human-wildlife conflicts may increase, disease may spread more quickly, food may become scarce, and habitat may become degraded. Managers may manage populations in one of two general ways:
Direct manipulation: Stocking, sterilization, hunting, and trapping.
Indirect manipulation, such as planting or removing vegetation or adding water sources, managers influence populations through their habitat needs.
There are several tools and techniques that wildlife biologists can use when monitoring and managing wildlife populations:
Observation: Wildlife blinds and binoculars provide the observation of animals without disturbing them.
Remote camera stations: Trail cameras with motion triggers set up to capture photos of wildlife, especially elusive species.
Radio telemetry: A set of collars and radios that allow researchers to track the location of individuals; can be used for large mammals such as bear, as well as birds, reptiles, and amphibians.
Cover boards: Metal or wooden boards used as amphibian and reptile habitat.
Nesting boxes: human-placed boxes which provide nesting and roosting area for birds and bats.
Mist nets: A thin net placed in flight paths to capture birds or bats.
Sherman live traps: Small mammal traps that allow capture with little to no harm to the animal.
Frequently these techniques are employed in mark-recapture studies. These types of studies help managers estimate the abundance and density of a particular wildlife population.
This method involves capturing individual animals, giving them a unique marker such as a tag, releasing them back into the natural population, and recapturing them later.
In game management, one goal is sustained yield. Sustained yield allows for the continued yield of a resource by periodic harvesting. This helps managers make decisions about hunting and fishing permits and limits.
Pittman-Robertson Act (1937): Provided funds for wildlife study, habitat restoration, and hunter education. This act enforces an 11% excise tax on hunting equipment, which in turn supports funding for habitat conservation and research.
Dingell-Johnson Act (1951): Provides funds for fisheries restoration and management. Hunting licenses provide the majority of state funds for fish and game management.
Duck Stamp Act (1934): (for hunting ducks) provide funds for management of wetlands for waterfowl and other wildlife.
Historically, market hunting, trapping for fur, and killing for elimination of the species from the area caused extinction of several species, and endangered other species. Elk, bison, gray wolf, beaver, and eastern cougar (now extinct) were completely eradicated from North Carolina by hunting and trapping.
White tailed deer and black bear populations were seriously threatened. Special measures have been taken to reintroduce beaver, red wolf, and elk populations; and to increase the bear and white-tailed deer populations, which have rebounded dramatically.
Every hunter in North Carolina is required to take a hunter safety and education course and have a valid hunting or fishing license.
Wildlife Diseases:
Rabies: Can be transmitted to humans, while others cannot. Rabies is carried and transmitted by warm-blooded mammals.
Mammals may also be carriers of ticks that are vectors for Rocky Mountain spotted fever or Lyme disease, which can be transmitted to humans.
Hemorrhagic disease: Affects the white-tailed deer and elk populations in North Carolina. It is caused by epizootic hemorrhagic disease (EHD) virus or bluetongue virus and is transmitted by biting flies in late summer.
This can influence the number of deer available for hunters and is loosely monitored by the Wildlife Resources Commission.
Chronic Wasting Disease (CWD): Common cervid (deer, elk, moose) disease that is neurological, transmissible, and always fatal. CWD was detected in North Carolina in March 2022. In response, the NC Wildlife Resources Commission established CWD Surveillance Areas with special regulations.
Chytrid fungus: Also known as “Bd” for its scientific name, is a disease that affects amphibians in North Carolina. It has been responsible for the decline in various species of salamanders, particularly in the Western part of the state. The fungus infects the skin of amphibians and makes it difficult for water to permeate through their skin.
Rana viruses: Impact amphibians, fish, and reptiles. Transmitted through close contact.
Causes inflammation of the limbs and organs of the infected species, most commonly frogs. Because both Chytrid Fungus and Rana viruses are often transferred from one population to another by humans.
Management steps include disinfecting equipment such as boots both before and after traveling to new sites, not relocating wild animals without the advice of a professional and not releasing captive animals such as pets.
White nose syndrome: Fungal infection that affects hibernating bats causing them to leave hibernation early, leading to starvation.