When a baby chick hatches from the egg, the chick imprints on the first moving object that it sees. The chick believes the imprinted object to be its mother, even if that object is a human being. Imprinting stamps the mind of a bird with a lifelong image of itself, and that initial stamp is irreversible.
Farmers have long known about imprinting. In ancient China, farmers imprinted their newly hatched ducklings with a special stick. Whoever carried that stick could lead great flocks of ducks through the fields each day and back home again at night to their roosts.
In 1973, a scientist named Konrad Lorenz won the Nobel Prize for his ground-breaking research around imprinting. Dr. Lorenz discovered that human-imprinted birds would not perform courtship rituals in the wild, because the birds were confused about their identity.
This research explained why human-imprinted whooping cranes would not mate when released into the wild. Now, when whooping crane chicks are hatched in captivity, their human caretakers wear giant crane costumes to feed the chicks, to make sure the chicks imprint to cranes, and never to people. This development has helped the wild whooping crane population begin to reestablish itself.
On our farm, we receive most of our chickens as day-old chicks mailed to us from a hatchery. When I open those boxes full of newly-born, chirping little chicks, they are imprinted with my image, and for the rest of their lives they run to me when I open the gate, and crowd around my heels and follow me.
Sometimes, however, a rogue hen will fly the coop and lay her eggs in secret somewhere in the forest. When these chicks hatch, they imprint to the mother hen. These bird-imprinted hens are skittish and they run away when I open the gate. Human-imprinted laying hens are much easier for a farmer to manage.
However, the best roosters are bird-imprinted—the chicks born to the rogue hens. These roosters understand the natural order—they maintain discipline in the hen house but they are not aggressive toward people. Usually, belligerent roosters that attack people are human-imprinted birds, and they think of people as competitors for their hens.
These days, my favorite imprinting technique is to have my six-year-old daughter open the box when baby chicks arrive in the mail. She imprints her sweet face onto the chicks, and when those chicks grow up into laying hens, they are very friendly to her when she goes out to collect their eggs.