EFFECT OF ENVIRONMENTAL ENRICHMENTS ON A CAPTIVE COLONY

OF CHIMPANZEES (PAN TROGLODYTES VERUS):

SOCIAL BEHAVIOURS & LEARNING

D. Frasson, C. Spiezio

ENRICHMENT

Enrichment is an animal husbandry

principle that seeks to enhance the quality of captive animal care by

identifying and providing the

environmental stimuli necessary for optimal

psychological and physiological well-

being (Hosey, 2005).

ANIMAL WELFARE SOCIAL BEHAVIOURS & LEARNING

Animal welfare: a captive managment that ensure theperformance of species-appropriate behaviours, socialinteractions, reproduction, etc… (Shepherson, 2002);

Social interactions are considered to be an importantfactor influencing the psycological well-being of mostnonhuman primates (Young, 2013);

An adequate environment enables nonhuman primates tolearn and perform many species-appropriate behaviours(Young, 2013).

AIM OF THIS STUDY

Evaluate the effect of two different structuralenrichments on a captive colony of chimpanzee (Pan troglodytes verus);

The purpose of the first enrichment -WATER POOL-was to diminish boredom and inactivity and improvesocial behaviours as play and grooming;

The purpose of the second enrichment -ARTIFICIAL TERMITE MOUND- was to stimulate termite fishing, a specie-specific behaviour.

MATERIALS & METHODS

MATERIAL & METHODS

Experimental area

MATERIAL & METHODS

PIEH -adult female-

MARION -subadult female-

OLE -adult male- BIG LUCY -adult female-

SOLO -adult male- KOUZE -subadult male-

EXPERIMENTAL PROCEDURE

• November 2014-February 2015;

• Focal animal continuous sampling method was used tocollect behavioural data (frequencies of behaviours)(Paterson, 2001);

• 3 periods of 15 sessions per subject (15-minutessession/subject). Total of 270 sessions:BASELINE: before enrichment;POOL: after installation of water pool;TERMITE: after installation of artificial termite

mound.

RESULTS ABNORMAL, INDIVIDUAL, INACTIVITY and SOCIAL BEHAVIOURS

ABNORMAL BEHAVIOURS: baseline > pool (Wilcoxon test: p < 0,05; w = 0);

SOCIAL BEHAVIOURS: baseline < pool (Wilcoxon test: p < 0,05; w = 13);

ABNORMAL BEHAVIOURS: baseline > termite (Wilcoxon test: p < 0,05; w = 0);

INACTIVITY: baseline > termite (Wilcoxon test: p < 0,05; w = 9);

SOCIAL BEHAVIOURS: baseline < termite (Wilcoxon test: p < 0,05; w= 7);

RESULTS INDIVIDUAL SUBCLASS

AUTOGROOMING: baseline > pool (Wilcoxon test: p < 0,05; w = 0);

FORAGING: baseline > pool (Wilcoxon test: p <0,05; w = 7,5);

MAINTAINANCE: baseline < pool (Wilcoxon test: p < 0,05; w = 9);

SOLITARY PLAY: baseline < termite (Wilcoxon test: p < 0,05; w = 1);

TERMITE FISHING: baseline < termite (Wilcoxon test: p < 0,05; w = 0);

All the subjects manifested more abnormal behaviours and autogrooming before the enrichment installation;

Marion, Kouze, Pieh and Solo are the subjects that manifested more inactivity before the enrichment installation;

Big Lucy and Ole manifested more inactivity during the pool period.

RESULTS ABNORMAL BEHAVIOURS, INACTIVITY and

AUTOGROOMING for SUBJECTS during the 3 PERIODS

RESULTS INDIVIDUL SUBCLASS for SUBJECTS during the 3 PERIODS

All the subjects manifested termite fishing after the installation of the enrichment;

Marion and Kouze are the subjects that manifested more solitary play after bothenrichment installation, Pieh only after the termite installation;

Kouze, Pieh and Solo are the subjects that manifested more attentive behaviours and maintainance behaviours after the pool installation.

RESULTS SOCIAL AFFILIATIVE BEHAVIOURS

GROOMING: baseline < pool (Wilcoxon test: p < 0,05; w = 13,5);

SOCIAL LOCOMOTION: baseline < pool (Wilcoxon test: p < 0,05; w = 8);

SOCIAL PLAY: baseline < pool (Wilcoxon test: p < 0,05; w = 12);

GROOMING: baseline > termite (Wilcoxon test: p < 0,05; w = 13,5);

SOCIAL PLAY: baseline > termite (Wilcoxon test: p < 0,05; w = 7);

RESULTS SOCIAL AGONISTIC BEHAVIOURS

DISPLAY: baseline > pool (Wilcoxon test: p < 0,05; w = 0);

DISPLAY: baseline > termite (Wilcoxon test: p < 0,05; w = 2);

DISCUSSION

Results of this study show that all individuals performspecies-specific individual and social behaviours;

All chimpanzees seem to benefit from theenrichments by:- decreasing abnormal behaviours and inactivity;- increasing social behaviours like grooming and social play;- eliciting species-typical tool-using behaviour;- decreasing agonistic display behaviours.

In particular, an increasing of play, grooming andtermite fishing was observed mainly in the youngsubjects of the colony (Marion and Kouze).

CONCLUSION

Structural enrichments seems to be a good tool to improve the subjects’ behavioural repertoire and to decrease boredom and inactivity of captive chimpanzees;

The age-dependent patterns seem to indicate that young individuals are more willing to learn new behaviours and take part in social interactions.

AcknowledgementBala Amarasekan, Sofie Meilang, Willy Tuker, Pastor Kamara, Ethel Sillah, Posh Bangura, Franklin Sesay, David Momoh, Joseph Marrah, Caterina Spiezio

Thanks for your

attention…