History of Conservation Efforts

### Conservation History

• Gifford Pinchot was trained abroad and appointed head of the US Forest Service. He coined the term "Conservation" and promoted the idea of "Sustained Use", advocating for the sustainable use of nature.
• John Muir founded the Sierra Club and campaigned to conserve Yosemite and the neighboring Hetch Hetchy Valley. While Yosemite was successfully protected, the effort to save Hetch Hetchy failed.
• Aldo Leopold, known as the "Father of Wildlife Management", played a key role in developing the field of wildlife management. He authored a significant report on North American Game Policy in 1930 and became the first professor of Game Management in 1933.
• The Pittman-Robertson Act of 1937 and the Dingell-Johnson Act of 1950 provided significant sources of funding for state fish and wildlife agencies.
• Rachel Carson's book, "Silent Spring" (1962) raised awareness about the detrimental effects of industrial practices on the environment.
• The Endangered Species Act (1973) was a landmark piece of legislation focused on protecting endangered species.

Era of Conservation Biology

• The Alaska National Interest Lands Act (1980) protected 101 million acres of land in Alaska, creating numerous conservation areas.
• Despite President Ronald Reagan's anti-environmental policies, progress was made in environmental protection during his presidency.
• Growing evidence of human population growth, climate change, deforestation, and pollution highlight the urgent need for effective conservation measures.

Overexploitation

• Overexploitation refers to unsustainable harvesting of natural resources, including hunting, trapping, collecting, and fishing at levels exceeding the capacity of ecosystems to replenish.
• Overexploitation poses the most significant threat to marine ecosystems.
• In the United States, hunting is generally well-managed, but overexploitation of certain species, such as prairie dogs, continues.
• Illegal wildlife killing, trophy hunting, and the wildlife trade pose threats in various countries.
• The Bushmeat Trade is a significant threat in tropical forests, leading to deforestation and species extinction.
• The pet trade is a major contributor to the illegal wildlife trade, with the US being a large destination for smuggled animals.

Habitat Loss, Degradation, and Fragmentation

• Habitat loss is considered the most severe threat to biodiversity and a major driver of animal extinctions.
• Habitat degradation affects multiple species and can result from various factors, including livestock grazing, invasive species, and pollution.
• Habitat fragmentation divides large habitats into smaller, isolated patches, leading to reduced population stability and biodiversity.
• Island biogeography theory suggests that the size and isolation of habitats influence extinction rates. Edge effects occur at the boundaries of fragmented habitats, altering environmental conditions and impacting species.
• Urbanization and conversion are major drivers of habitat loss. Conversion refers to transforming one habitat type into another, often for agricultural or other development purposes.
• Wetlands are crucial for maintaining water quality, quantity, and providing essential habitats for numerous species.

Wildlife Diseases

• Wildlife diseases have implications for conservation efforts, human health, livestock, and recreational use of wildlife.
• Epizootic refers to a disease outbreak occurring at unexpectedly high rates.
• Zoonoses are animal diseases transmissible to humans. Examples include Lyme disease, West Nile Virus, Ebola, and COVID-19.

Introduced Species

• While some introduced species have a positive impact, like those used in agriculture, invasive species can have severe ecological consequences.
• Invasive species threaten approximately 20% of endangered species. The Zebra Mussel is a prominent example, causing significant damage to ecosystems.
• Ocean acidification is a growing concern, impacting marine life and contributing to ecosystem changes.

Extinction

• Anthropogenic causes of extinction include: overexploitation, habitat degradation, introduced species, disease, pollution, and climate change.
• Ecological extinction, local extinction (extirpation), and global extinction are forms of extinction.
• Rarity, narrow range, large area requirements, low reproduction rates, and specialization increase vulnerability to extinction.
• Cascade effects occur when one extinction triggers a chain reaction of others.
• Dominant species, ecosystem engineers, and keystone species are crucial for maintaining ecosystem function and are particularly vulnerable to extinction.
• The IUCN Red List provides a comprehensive assessment of species extinction risk.