Escape response

Threat detection notifies an animal to a potential predator or otherwise dangerous stimulus, which provokes escape initiation, through neural reflexes or more coordinated cognitive processes.

[4][5][6][7][8] The behaviors themselves differ depending upon the species, but may include camouflaging techniques, freezing, or some form of fleeing (jumping, flying, withdrawal, etc.).

[9] In addition, it is not merely increased speed that contributes to the success of the escape response; other factors, including reaction time and the individual's context can play a role.

[3][9] Those animals that learn to or are simply able to avoid predators have contributed to the wide variety of escape responses seen today.

[10] Because of this, it is common for the individual escape response of an animal to vary according to reaction time, environmental conditions, and/or past and present experience.

[15] 'Simple' escape responses are commonly reflex movements that will quickly move the animal away from the potential threat.

[3] These neural circuits operate quickly and effectively, rapidly taking in sensory stimuli and initiating the escape behavior through well-defined neuron systems.

[17] This means rapid integration of incoming information with prior knowledge, and then coordination of motor movements deemed necessary.

[3] Researchers will often evoke an escape response to test the potency of hormones and/or medication and their relationship to stress.

[18] A series of initially threatening encounters that do not lead to any true adverse outcomes for the animal can drive the development of habituation.

[22] Caenorhabditis elegans, commonly identified as nematodes, have been used as a model species for studies observing their characteristic "tap-withdrawal response".

This reflex causes a change in body posture, emotional state, or a mental shift to prepare for a specific motor task.

[28] A common example would be cats and how, when startled, their arrector pili muscles contract, making the hair stand up and increase their apparent size.

Another example would be excessive blinking due to the contraction of the orbicularis oculi muscle when an object is rapidly moving toward an animal; this is often seen in humans.

The acoustic startle reflex is only activated when the noise is over eighty decibels, which promotes stress and anxiety responses that encourage flight.

As the threatening stimuli moves forward and decreases the flight zone, the dog will exhibit behaviors that fall into a startle or avoidance response.

Individuals are able to recognize certain species or environments that need to be avoided, which can allow them to increase the flight distance to ensure safety.

One study by Michael A. Weston et al. in 2020 observed how flight initiation changed according to the distance of the drone from the birds.

[35] In another experiment by Travis L. DeVault et al. in 1989, brown-headed cowbirds (Molothrus ater) were exposed to a demonstration of traffic traveling at speeds between 60–360 km/h.

[34] This study showed that fast traffic speeds may not allow enough time for birds to initiate an escape response.

In fish and amphibians, the escape response appears to be elicited by Mauthner cells, two giant neurons located in the rhombomere 4 of the hindbrain.

While many predators use water pressure to catch their prey, this short distance prevents them from feeding on the fish via suction.

[40] Particularly in the case of fish, it has been hypothesized that the differences in escape response are due to the evolution of neural circuits over time.

[40] Recent research in guppies has shown that familiarity can affect the reaction time involved in the escape response.

A recent research suggests that the escape response in Musca domestica is controlled by a pair of compound eyes, rather than by the ocelli.

[43] The sensory neurons in the paired caudal cerci (singular: cercus) at the rear of the animal send a message along the ventral nerve cord.

[3] In 2007, Theodore Stankowich and Richard G. Coss studied the flight initiation distance of Columbian black-tailed deer.

[50] Finally, the released ink also contains hormones such as L-dopa and dopamine that can warn other conspecifics of danger while blocking olfactory receptors in the targeted predator.