What is Innate Releasing Mechanism (IRM) regarding animal behavior?
It could also be consider a reflex or an "instinctive behavioral sequence".
The term “innate releasing mechanism” belongs to a classical concept of ethology. It refers to a neural sensorimotor interface that mediates between a key stimulus and the adequate action pattern.
An IRM thus has stimulus recognition and localization properties at its input side and behavior-releasing properties at its output side. The IRM should allow an animal to recognize and respond a behaviorally relevant object that the animal had never encountered before.
The term “innate,” however, is controversial since it may have different meanings, such as present at birth, a behavioral difference caused by a genetic difference, adapted over the course of evolution, unchanging throughout development, shared by all members of a species, present before the behavior serves any function, not learned.
The term fixed action pattern, or modal action pattern, is sometimes used in ethology to denote an instinctive behavioral sequence that is relatively invariant within the species and almost inevitably runs to completion.