Association brings us back to medieval times when people believe all the birds chose mate on Valentine's Day. Although some birds find a mate for mid-February, including blackbirds, and partridges, most of the bird breeding season takes place during the spring and summer.
Doves were chosen to represent love for Greek mythology associated with Aphrodite little white bird / goddess of love. Aphrodite / Venus is often depicted with dove flying around or resting in his hand.
Dove also represent monogamy and fidelity in a relationship because birds tend to stay with mate during the mating season.
A male dove also helped incubate and care for their children, which helps achieve the image of this bird loyal and loving.
In fact, their reputation as a symbol of love so strong and make a lot of prescription drugs popular in medieval love insert the heart of doves as a material.