Behavioural responses in captive male Asian elephants (Elephas maximus) to specified stressors
Loading...
Files
Date
2003
Journal Title
Journal ISSN
Volume Title
Publisher
Department of Livestock Production Management, College of Veterinary and Animal Sciences, Mannuthy
Abstract
Assessing the welfare status of captive male Asian elephants is a growing
area of concern, as ethical questions are raised about the psychological well-being of
animals maintained in captivity. The study was undertaken as a synthesis of
approach to measure stress through physiological and behavioural studies to
quantify the welfare and ensure the well-being of elephants in captivity. Captive
male elephants maintained at the "elephant camp" in Punnathur Kotta under the
Guruvayoor Devaswom Board were utilized for the present study. The animals were
divided into seven groups: group I (musth), group 11 (travel), group III (disease),
group IV (restraint), group V (summer), group VI (monsoon) and group VII
(normal). All the behavioural and physiological data were collected from the
individual animals in the above mentioned groups.
A total of forty two behaviours grouped into combined variables, were
measured by focal-animal sampling technique using a behaviour check sheet to
identify the behaviours indicative of stress. A total of thirty two hours of
behavioural data were collected from four animals in each group, with eight hours of
observation on each animal. The data were then analyzed using non-parametric tests
to determine the significance of stress related behaviours. Most of the behaviours
were performed with higher significance in group I followed by other groups in
conjunction with a description of the context within which it takes place as an
indicator of stress. The results indicate that musth is the single most stressful event.
The prominent stress related behaviours identified during the present study were
r.o
stereotypes, temporal gland secretion and aggression. The frequency or intensity of
performance of other behaviours was in line with the severity of the stressful event.
A good correlation between the cortisol values and behaviour scores indicates that
both physiological and behavioural measures can be used in conjunction as potential
non-invasive methods to assess stress. Other physiological measures like rectal
temperature and respiratory rate could not be used as a measure of stress, since the
healthy subjects have the physiological and behavioural ability to cope with varying
conditions of stress to maintain the normal homeostasis.
Urine and faecal samples collected from animals in each group were stored
at -20°C until it was processed and analyzed for measurement of cortisol metabolites
by radioimmunoassay technique and urine creatinine concentrations by enzyme
immunoassay technique using standard procedures. Urine creatinine concentrations
were analyzed to counteract the variations in fluid intake by individual animals.
Mean urine cortisol concentrations were found to be highest during musth (143.60 ±
30.07 ng/mg Cr) followed by restraint (115.62 ± 20.65 ng/mg Cr), disease (102.86 ±
22.44 ng/mg Cr), travel (93.07 ± 19.78 ng/mg Cr), summer (73.55 ± 11.95 ng/mg
Cr) and monsoon (69.13 ± 11.63 ng/mg Cr) when compared to the mean values in
normal group (59.98 ± 8.45 ng/mg Cr), indicative of the level of stress in each
group. Similarly mean faecal glucocorticoid metabolite concentrations (11,17-
dioxoandrostanes) were highest during musth (449.02 ± 86.31 nmol/kg) followed by
restraint (354.62 ± 72.07 nmol/kg), summer (337.85 ± 41.94 nmol/kg), disease
(335.52 ± 56.81 nmol/kg), travel (300.14 ± 50.71 nmol/kg) and monsoon (249.60 ±
44.31 nmol/kg). Both the urine cortisol concentrations and faecal cortisol metabolite
concentrations followed a similar trend in the values indicating that, both the
methods can be used as a measure for reliable indicator of stress. The results suggest
that, musth is the most stressful event and monsoon season the least stressful event.
The results of the present study suggest that, integrating the endocrine
assessment, such as cortisol levels in the urine and faeces, with other evaluations
based on behaviour could potentially provide a more meaningful measure of stress
in captive living male Asian elephants and can help resolve the managemental
problems. The study underlines the feasibility of measuring faecal and urine cortisol
metabolites combined with behavioural measure as a non-invasive approach, to
answer questions such as animal welfare and stress in captive elephants.
Description
PG
Keywords
null
Citation
172167