* Deforestation: The clearing of forests for logging, agriculture, or other purposes destroys habitat for countless plant and animal species.
* Urbanization: The expansion of cities and towns into natural areas takes away habitat from native species.
* Pollution: Pollution of air, water, and soil can make habitats uninhabitable for many species.
Overexploitation: This occurs when a species is hunted, fished, or otherwise harvested at a rate that is faster than it can reproduce. Overexploitation can be caused by a number of factors, including:
* Commercial hunting and fishing: Many species are hunted and fished for their meat, fur, skin, or other body parts. This can lead to population declines and even extinction.
* Illegal trade: The illegal trade in wildlife is a major threat to many species. Animals are often captured from the wild and sold into the pet trade, fur trade, or other markets.
* Bycatch: Bycatch occurs when animals are unintentionally caught in fishing gear or other traps. This can lead to the deaths of large numbers of animals, including many that are not targeted by fishermen.
Climate change: Climate change is causing the Earth's climate to change at an unprecedented rate. This is disrupting ecosystems and causing many species to lose their habitats. Climate change can also lead to changes in the availability of food and water, which can make it difficult for species to survive.
Invasive species: Invasive species are non-native plants and animals that have been introduced to an area outside of their natural range. Invasive species can compete with native species for resources, such as food and habitat, and can also transmit diseases.
Disease: Disease can be a major threat to species, especially when it is introduced to a population that has not been previously exposed to it. Diseases can spread quickly through a population and can cause widespread death.
War and persecution: War and persecution can also lead to species extinction. War can destroy habitat, kill animals directly, and disrupt food chains. Persecution, such as hunting or poisoning, can also lead to the deaths of large numbers of animals.