What is Imprinting (ethology)?
[[File:Momma Duck Leads The Way.jpg|right|250px|thumb|Imprinting keeps the family together]] [[File:Ducks army marching.jpg |right|250px|thumb|Ducklings in line]] [[File:Tadorna variegata -Opunake Beach -NZ-8.jpg|right|250px|thumb|[[New Zealand]] Paradise Shelduck with ducklings]] [[Image:Christian Moullec 4.jpg|thumb|250px|Imprinted geese and [[Crane (bird)|cranes]] flying with an ultralight aircraft]] '''Imprinting''' is a term used in [[ethology]] and [[psychology]] to describe a special type of automatic [[learning]]. It usually occurs early in life, ''during a critical period''. That is why the textbooks call it ''phase-sensitive learning''. It is learning which happens at a particular age or a particular life stage. The animal fixes on a particular signal (sound or sight), which is said to be 'imprinted' onto the subject. The process of imprinting is caused by an [[heritable|inherited]] [[instinct]]. The best-known form of imprinting is the imprinting of the newly-hatched (or born) on one or both parent. Its function is to keep the young near their parent(s) during the early learning period. It is most obvious in birds, such as [[duck]]s and [[geese]], after the fledglings have left the nest. They imprint on their parents and then follow them around, often in a long line, on land and on water. It was first reported in domestic [[chicken]]s, by the 19th-century amateur biologist [[Douglas Spalding]]. It was rediscovered by the early ethologist [[Oskar Heinroth]], and studied extensively and popularised by his disciple [[Konrad Lorenz]], and by [[Niko Tinbergen]].<ref>Tinbergen, Niko 1951. ''The study of [[instinct]]''. Oxford University Press.</ref> Lorenz showed how incubator-hatched geese would imprint on the first suitable moving stimulus they saw within what a 'critical period' of 13–16 hours after hatching. For example, the goslings would imprint on Lorenz himself (to be more specific, on his wading boots). He is often shown in photographs being followed by a gaggle of [[geese]] who had imprinted o