Imprinting (psychology) - Filial Imprinting

The best-known form of imprinting is filial imprinting, in which a young animal acquires several of its behavioral characteristics from its parent. It is most obvious in nidifugous birds, which imprint on their parents and then follow them around. It was first reported in domestic chickens, by the 19th-century amateur biologist Douglas Spalding. It was rediscovered by the early ethologist Oskar Heinroth, and studied extensively and popularized by his disciple Konrad Lorenz working with greylag geese. Lorenz demonstrated how incubator-hatched geese would imprint on the first suitable moving stimulus they saw within what he called a "critical period" between 13–16 hours shortly after hatching. For example, the goslings would imprint on Lorenz himself (to be more specific, on his wading boots), and he is often depicted being followed by a gaggle of geese who had imprinted on him. Lorenz also found that the geese could imprint on inanimate objects. In one experiment, they followed a box placed on a model train in circles around the track. Filial imprinting is not restricted to non-human animals that are able to follow their parents, however. In child development, the term is used to refer to the process by which a baby learns who its mother and father are. The process is recognised as beginning in the womb, when the unborn baby starts to recognize its parents' voices.

The filial imprinting of birds was a primary technique used to create the movie Winged Migration (Le Peuple Migrateur), which contains a great deal of footage of migratory birds in flight. The birds imprinted on handlers, who wore yellow jackets and honked horns constantly. The birds were then trained to fly along with a variety of aircraft, primarily ultralights.

The Italian hang-glider pilot Angelo d'Arrigo extended this technique. D'Arrigo noted that the flight of a non-motorised hang-glider is very similar to the flight patterns of migratory birds: Both use updrafts of hot air (thermal currents) to gain altitude that then permits soaring flight over distance. He used this fact to enable the re-introduction into the wild of threatened species of raptors.

Birds that are hatched in captivity have no mentor birds to teach them their traditional migratory routes. D'Arrigo had one solution to this problem. The chicks hatched under the wing of his glider, and imprinted on him. Then, he taught the fledglings to fly and to hunt. The young birds followed him not only on the ground (as with Lorenz) but also in the air as he took the path of various migratory routes. He flew across the Sahara and over the Mediterranean Sea to Sicily with eagles, from Siberia to Iran (5,500 km) with a flock of Siberian cranes, and over Mount Everest with Nepalese eagles. In 2006, he worked with a condor in South America.

In a similar project, orphaned Canada Geese were trained to their normal migration route by the Canadian ultralight enthusiast Bill Lishman, as shown in the fact-based movie drama Fly Away Home.

Chicks of domestic chickens prefer to be near large groups of objects that they have imprinted on. This behaviour was used to determine that very young chicks of a few days old have rudimentary counting skills. In a series of experiments, they were made to imprint on plastic balls and could figure out which of two groups of balls hidden behind screens had the most balls.