Rarely do poachers kill animals for sport. Although, some do. For the most part, poachers kill animals for the money. When they kill certain animals like rhinos, elephants and leopards, it is because they can get a lot of money from certain body parts of these animals. For example, elephants are slaughtered for their tusks. These tusks are made of ivory. People need ivory for different things like piano keys.
Leopards are killed for their fur. Their fur is used in making coats. Therefore, the poachers may do illegal hunting so that they can make money. When their economy in their country goes down, these citizens may need to find different ways of making money and they think of poaching.
Poaching is illegal yet popular in almost every area of the world. Unfortunately, there are several reasons for this. The first reason being the fact that many developing nations don't have opportunities for work and to make a living—those that do have those opportunities make very little doing so. There is also a high demand for endangered or exotic animals.
To meet this demand, poachers will kill or capture wildlife to sell at a high price, often to the highest bidder. Even in the United States, hunters will poach by harvesting animals out of season or on land that is supposed to be protected. Regardless of location, it's popular because it's unlikely to be caught and if caught, punishment is not severe.