Fixed Action Pattern
"(im pryn ting): a type of learned behaviour with a significant innate component, acquired during a limited critical period" [Campbell, Biology 4th Edition]
Picture from Bird Photograph and Song: White-throated Sparrow. Used with permission.
In this example, male sparrows imprint songs that they sing for courtship. They need to hear a specific song during their critical period (for 10 to 50 days) to be able to sing songs of conspecifics. Imprinting is not genetic, so if the male sparrows hear other songs during the critical period, they will sing a different song from conspecifics.