The male forms a territory. The territory is usually on the top of a hill. The male will sit on high branches or other vegetation on the hill. He will defend his territory from other male Black Swallowtails. If other males come too close, he will chase them away. The female will fly to the top of the hill to look for a mate. A successful courtship lasts for about 40 seconds. An unsuccessful one lasts for about 100 seconds. Mating lasts for about 45 minutes. Females that do not want to mate will try to escape from males by flying high in the air and then quickly flying downward.