Bird flu is an infection caused by avian (bird) influenza (flu) viruses. These flu viruses occur naturally among birds. Wild birds worldwide carry the viruses in their intestines, but usually do not get sick from them. However, bird flu is very contagious among birds and can make some domesticated birds, including chickens, ducks, and turkeys, very sick and kill them. Gold Bamboo Special Report on Bird Flu

Fever, also known as pyrexia, is a medical symptom which describes an increase in internal body temperature to levels which are above normal (37 degrees Celsius, 98.6 degrees Fahrenheit). An adaptive mechanism, fever is the body's reaction to pathogens; it attempts to raise core body temperature to levels which will denature, debilitate, or kill the pathogen. Most fevers are caused by infections and almost all infectious diseases can cause fever. ...