Overexploitation

People, with their natural abilities, are rather weak compared to other animals. We don't have claws to attack, thick fur or feathers for warmth, sharp senses (compared to others), tails, or swift running. But we are a very intelligent species and have developed tools and weapons to hunt, harvest, and live off resources when other animals were naturally born with their "tools".

Overexploitation is taking too much of resources from the wild, such as animals and plants, to make clothing, medicine, pets, and others. We affect many different species, such as aquatic species, birds, mammals, amphibians, reptiles, invertebrates, and plants.

Fishing has become very efficient, but is also causing the rapid decline in populations of fish. 

Many birds are kept as pets, and others are hunted for food or just game. 

According to National Wildlife Federation, "People have always hunted mammal species—for fur, food, sport, and for their horns or antlers. Mammals are also trapped for the pet trade, zoos and biomedical research. Today, illegal hunting still threatens many species, especially large mammals such as tigers, rhinoceros, bears and even primates, whose body parts are highly valued in some parts of the world for traditional medicine."

Amphibians, like frogs, are used in education, pets, and medicine. Many biology classes dissect frogs. Frogs are also a source of food, and the California red-legged frog is now endangered due to overhunting for food.

According to National Wildlife Federation, "Reptiles are harvested and traded around the world for their skins or shells, their eggs, meat, and for the pet trade....Some reptile skins—such as crocodile, python and monitor lizard—are highly prized as exotic leathers."

"Plants are vital to our survival and are the foundation of most of the Earth’s ecosystems. People harvest plants for food, medicine, building materials, and as raw materials for making other products.  But we are taking too many plants from the wild. Some plants, such as orchids, are so prized by collectors that they are now endangered and  legally protected from poaching by international law. Some medicinal plants, such as American ginseng, have also been so enthusiastically collected that it is now very hard to find them in the wild. A number of tree species that are prized for their wood, such as mahogany, are under threat because of overharvesting" (National Wildlife Federation).

Info source: http://www.nwf.org/Wildlife/Threats-to-Wildlife/Overexploitation.aspx