TY  - JOUR
A1  - Hambrecht, Susan
A1  - Oerke, Ann-Kathrin
A1  - Heistermann, Michael
A1  - Hartig, Johannes
A1  - Dierkes, Paul W.
T1  - Effects of positive reinforcement training and novel object exposure on salivary cortisol levels under consideration of individual variation in captive African elephants (Loxodonta africana)
T2  - Animals
N2  - Dealing with potential stress in species that have high husbandry requirements, such as elephants, is a challenge for zoos. The objective of the present study was to determine whether positive reinforcement training (PRT) and exposure to a novel object (NOV) for enrichment induced a salivary cortisol response indicative of activation of the hypothalamic–pituitary–adrenal (HPA) axis and which factors determine individual variation in this regard in captive African elephants. We repeatedly sampled the saliva of ten animals (three zoos) for the analysis of cortisol (SACort) before and up to 60 min (in 10–15 min intervals) after the onset of PRT (three repeats) or NOV (nine repeats), which lasted 10 min. There was considerable individual variation in SACort in response to PRT or NOV. Using mixed models, we were able to control these and to reveal that PRT was associated with high SACort before and relatively low SACort after PRT, while NOV induced a moderate SACort increase. The individual differences in SACort were related to age and sex (NOV), while the effects of zoo, handling method (free vs. protected contact) and reproductive and social status were variable. We conclude that positive affective states, such as anticipation or arousal, should be taken into account when interpreting the differences in the SACort responses between PRT and NOV. In addition, understanding the individuality of stress will support management decisions aimed at promoting captive elephant welfare.
KW  - zoo elephants
KW  - individuality
KW  - physiological stress
KW  - glucocorticoid response
Y1  - 2021
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/69286
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-692862
SN  - 2076-2615
N1  - This work was supported by the Opel-Zoo Foundation Professorship Zoo Biology, which is financed by the von Opel Hessische Zoostiftung.
N1  - Data Availability Statement
We hereby confirm that the data set supporting the conclusions of this article will be made available in a publicly accessible repository (Dryad) after publication.
VL  - 11
IS  - 12, art. 3525
SP  - 1
EP  - 24
PB  - MDPI
CY  - Basel
ER  -