Birds
Birds are perfect flying animals. More than 9000 species are known. Their capability to fly allowed them to spread over the globe down to the Antarctics and very remote islands, i.e. areas beoynd the reach of many other animals. Birds as well as mammals are referred to endotherms but they reproduce themselves by ovipositing. Birds have special means helping them to fly such as wings, feathers, light but very strong skeleton and developed respiratory system. The biggest danger for this group besides ruining of wildlife habitual areas is hunting and catching for sale.