Tarn: These are the giant riding birds of , also called the Brothers of the Wind. They resemble a hawk but with a crest like a jay. They are surprisingly light for their size due to the hollowness of their bones. A tarn is an extremely powerful bird. It can fly from the ground with a spring and sudden wing flurry. Its tongue is thin, sharp and as long as a man's arm. It has a curved beak, slit with narrow nostrils. They are not migratory birds and cannot live in the cold northern regions. Tarns are diurnal and carnivorous. They eat only what they catch themselves, usually antelopes and wild bull. If enough food is available, they will eat half their weight. By the time of Renegades of , tarns are being trained to eat prepared meat. They are seldom more than half-tamed and it is not unknown for a tarn to attack its own rider. Their plumage varies and they are bred for color. The most common color is greenish-brown. Black tarns are used for night raids, white for winter raids, and multi-colored for proud warriors who care not for camouflage. It is extremely difficult to fly a tarn from the sight of land. The jungle tarn is a rare bird, gloriously plumaged, from the tropical reaches of the Cartius. Tarns often are trained for specific functions. Draft tarn is used for transporting cargo while saddle tarns are used for transport of people. War tarns are used by tarnsmen in battle. Racing tarns are made for entertainment like Earth horse racing. Racing tarns are different in size, strength, build, and tendencies from most other tarns. They are extremely light so that two men could lift one. Its wings are broader and shorter permitting a swifter take-off and a capacity for extremely abrupt turns and shifts in flight. They lack the stamina of most other tarns and cannot carry heavy weight.