Abnormal Behavior Definitions

Abnormal behavior has been observed in a wide variety of primate species housed in zoos, laboratories and sanctuaries. Behaviors can be considered abnormal if they are qualitatively different (i.e., occur in captivity but not typically in the natural setting) or quantitatively different (i.e., occur significantly more or significantly less than what is observed in the natural setting). Although abnormal behavior does not generally cause an animal harm, it can be an indicator of suboptimal environments, either past or present. Therefore, abnormal behavior is often used as a measure of wellbeing in captive nonhuman primates.

Establishing common definitions is a critical step in the standardization of terminology and assessment tools. This standardization is necessary for cross-center collaborative research, not only for attaining inter-observer reliability in data collection, but also to identify study subjects when employing inclusion criteria that focus on particular behaviors. This research will guide continued refinement of practices used to minimize the development and optimize the treatment of abnormal behavior.

Abnormal Behavior Ethogram

Bizarre Posture: Holding a seemingly uncomfortable or contorted position

Bob: A rapid and repetitive* up and down motion of the body on flexed limbs; animal does not leave the cage surface

Bounce: Repetitively* using one’s hind legs or all four limbs to push oneself off the cage surface

Coprophagy: Ingesting or manipulating feces in the mouth

Eye Poke/ Salute (Periorbital contact): Animal holding hand, digit, and/or object against/near one's eyebrow or eye

Feces paint: Smearing and/or rubbing feces on a surface

Flip: Repeated forward or backwards somersaults, may utilize the cage sides or ceiling

Floating limb: An arm or leg rises into the air and may or may not contact the body (e.g., gently stroking the body). The action appears to be non-volitional; the animal may interact with the limb as if it is not part of the body. This behavior may be associated with SIB such as self-biting or self-hitting

Food smear: Spreading of chewed food on a surface with the mouth; food is often licked off

Hair Pluck: Removal of hair from one’s own body by pulling with teeth or hands, often seen with a quick jerking motion

Head banging: Repetitively* and forcefully hitting the head against an object or surface

Head toss: Repetitively*moving head side to side, or in a circular manner

Pace: Repetitive* locomotion following the same path- for example, walking back and forth on the ground, around the enclosure, or back and forth across bars

Regurgitate: The backward flow of already swallowed food- the material may be retained in the mouth or deposited on a surface and re-ingested

Repetitive Licking: Prolonged or excessive contact of tongue with a surface or object for no apparent reason

Rock: Any rhythmic motions of the body from a stationary position. Animal remains sitting or standing while the upper torso sways back and forth

Self-bite: Closing teeth rapidly and with force on oneself

Self-clasp: Clutching one's own body with hands or feet

Self-injure: Any behavior by the animal that causes physical trauma to itself such as bruising, lesions, lacerations, or punctures

Self-oral: Sucking a part of one's own body

Self-slap: Forcibly striking oneself with hands or feet

Spin: Repetitive*circling of body around a pivot point

Urophagy: Licking or ingesting urine

Withdrawn: Slumped or hunched body posture, often accompanied by dull eyes, and relatively unresponsive to environmental stimuli to which other monkeys are or typically would be attending

Other Stereotypical locomotion: Idiosyncratic repetitive* whole body movements, particular to an individual; does not meet criteria for other behaviors defined above

*Repetitive = a minimum of 2 or 3 times, depending on your facility’s criteria

Abnormal Behavior Publications

Jacobson SL, Ross SR, Bloomsmith MA.
Characterizing abnormal behavior in a large population of zoo-housed chimpanzees: prevalence and potential influencing factors.
PeerJ 2016 08; 4(): e2225.

Lutz CK, Williams PC, Sharp RM.
Abnormal behavior and associated risk factors in captive baboons (Papio hamadryas spp.).
Am. J. Primatol. 2014 Apr; 76(4): 355-61.

Lutz CK.
Stereotypic behavior in nonhuman primates as a model for the human condition.
ILAR J 2014 09; 55(2): 284-96.

Martin AL, Bloomsmith MA, Kelley ME, Marr MJ, Maple TL.
Functional analysis and treatment of human-directed undesirable behavior exhibited by a captive chimpanzee.
J Appl Behav Anal 2011 05; 44(1): 139-43.

Nevill CH, Lutz CK.
The Effect of a Feeding Schedule Change and the Provision of Forage Material on Hair Eating in a Group of Captive Baboons (Papio hamadryas sp.).
J Appl Anim Welf Sci 2015 09; 18(4): 319-31.

Pomerantz O, Meiri S, Terkel J.
Socio-ecological factors correlate with levels of stereotypic behavior in zoo-housed primates.
Behav. Processes 2013 Sep; 98(): 85-91.

Pomerantz O, Paukner A, Terkel J.
Some stereotypic behaviors in rhesus macaques (Macaca mulatta) are correlated with both perseveration and the ability to cope with acute stressors.
Behav. Brain Res. 2012 Apr; 230(1): 274-80.

Pomerantz O, Terkel J, Suomi SJ, Paukner A.
Stereotypic head twirls, but not pacing, are related to a 'pessimistic'-like judgment bias among captive tufted capuchins (Cebus apella).
Anim Cogn 2012 Jul; 15(4): 689-98.