Carrier pigeons are actually domesticated rock pigeons and not extinct. The International Union for Conservation of Nature has categorized rock pigeons in the "least concern" category. Rock pigeons are no longer used in any official capacity.
Carrier pigeons can cover 99 miles in a round trip, carrying up to 2.5 ounces. Carrier pigeons were used in ancient Greece to announce the Olympic winners. The birds were also used in the Franco-Prussian War, World War I and World War II. The carrier pigeon Cher Ami was used in World War I and saved the lives of several American soldiers by transporting vital messages. The last official pigeon carrier service was used in India as an emergency communication relay in case of a natural disaster. This service ended in 2002.