1. INTRODUCTION
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2. Bradshaw, G. A., Capaldo, T., Lindner, L., &
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(1982). A vocabulary of abnormal behaviors
in restrictively reared chimpanzees.
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5. Lopresti-Goodman, S., Kameka, M., &
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chimpanzees rescued from the African
bushmeat and pet trade. Behavioral
Sciences, 3, 1-20.
al
Abnormal Behaviors in Captive Chimpanzees
Lorine Margeson & Stacy M. Lopresti-Goodman, Ph.D.
Department of Psychology, Marymount University, Arlington, VA, USA
This research was supported in part by a Virginia Foundation for Independent Colleges Summer Research Grant to Lorine Margeson, and a Marymount University Research Grant to Stacy M. Lopresti-Goodman
In Africa, chimpanzees are illegally killed for their meat
(bushmeat) and their infant orphans are sold as “pets.”
Despite living in an enriched sanctuary setting, Poco still
engages in a variety of abnormal, self-injurious behaviors.
Poco’s case demonstrate the life-long psychological harm
maternal deprivation, social isolation, and poor captive
conditions have on chimpanzees.
Chimpanzees are an endangered species. If we don’t stop
bushmeat hunting, and their use in biomedical research,
the “pet” trade and use in entertainment in the US, they
will become extinct in our lifetime.
BACKGROUND:
Male Chimpanzee, estimated to be born and separated from his
mother in 1981. Lived alone in a small cage suspended from the
ceiling of a service station for 9 years in Burundi.
Rescued by the Jane Goodall Institute Sanctuary in Bujumbura,
Burundi in 1989.
In 1995 was relocated to the Sweetwaters Chimpanzee Sanctuary
in Nanyuki, Kenya. Lives with 38 other chimpanzees on 200 acres
of enclosed, protected land.
In 2011, second author determined through caregiver interviews,
case file review, and behavioral observations that Poco meets
behaviorally modified criteria for PTSD in chimpanzees (5).
Abnormal behaviors (N = #) included: self-poking with sharp thorn, aggressive outbursts towards humans, masturbating,
eats his own feces (coprophagy), and flips his upper lip.
Was human oriented 51.88% of the observation time, solitary 40.9%, agonist .16%, affinitive 6.43% and submissive only
.63%
Caregiver interviews indicated he is often solitary and only socializes with a few other chimpanzees. He has never been
seen mating with a chimpanzee before and is in constant fear from other chimpanzees or big men.
Captivity can cause abnormal or species atypical
behaviors and psychological distress from maternal
separation, social isolation, and ethologically
inappropriate living conditions (1, 2, 3).
Most common abnormal behaviors include self-
scratching, -biting, -poking, -clasping, eating feces,
masturbating, grooming stereotypically, and rocking (3).
METHODS:
Conducted non-intrusive behavioral observations for 12 hr, in 30 min blocks, using instantaneous focal animal sampling,
with 1 min intervals, over six days in June, 2014. Recorded both normal and abnormal behaviors and behavioral contexts
(e.g. human oriented, solitary, social).
Interviewed caregivers to gather qualitative data about normal and abnormal behaviors Poco engages in.
Marymount University’s Institutional Review Board approved all procedures.
Poco self-clasping in a depressed posture.
© Jane Goodall Institute
RESULTS:
Normal 90.6%
Abnormal 9.4%
Behavioral Distribution Behavioral Contexts
Chimpanzee 5.6%
Solitary 36.17% Human 46%
Poco solitary, self-clasping, while scratching
flesh with sharp thorn (see inset).
CASE STUDY: POCO DISCUSSION
CONCLUSION
REFERENCES
Some abnormal behaviors resemble symptoms of Post-
Traumatic Stress Disorder (PTSD); avoidance behaviors,
social withdrawal, lack of interest in play, food, grooming,
easily angered and startled, extremely watchful (1, 4, 5).
I believe Poco will exhibit abnormal behaviors when
people are around because he was in captivity for a long
period of time and people cause him stress.
Behaviors may be result of trauma prior to rescue, brought
about by boredom, habit, or caused by the presence of
human visitors to the sanctuary. Most abnormal behaviors
occurred when he was human oriented.
While he spent most of time engaging in normal behaviors
(e.g. eating, resting), was socially isolated and human
oriented, which is abnormal.
Some normal behaviors, such as nest making, were
engaged in stereotypically, or mechanistically and without
an apparent function or purpose.
Chimpanzees grooming at Sweetwaters.
Poco frantically made nests, then destroyed
them and made new ones repeatedly.