Table 1.
Species, sex, and age distribution of elephants included in the study (N = 220).
Table 2.
Description of event type and subtype used to categorize clinical data recorded during the 12-month study period in African and Asian elephants in North American zoos.
Table 3.
Description of variables used in the analysis of the number of clinical events recorded during the 12-month study period in African and Asian elephants in North American zoos.
Fig 1.
Numbers of clinical events (n = 1103) recorded within a 12-month period for 127 African and 93 Asian elephants in North American zoos. Dotted bars represent sub-categories.
Fig 2.
The number of clinical events recorded for each individual elephant, plotted according to their age at the start of the recording period. Markers denote individual elephants by species and sex; fit lines represent the GLMM predicted number of clinical events by age according to species, sex and overall.
Table 4.
Univariate analyses investigating relationships between independent variables and the total number of clinical events per animal in African and Asian elephants in North American zoos.
Hypotheses (H): positive (+), negative (-), or neutral (/) relationship of each variable with the number of clinical events per animal as a measure of elephant welfare, and whether observed relationships (P<0.15) were in the predicted direction (Y yes / N no).
Table 5.
Multivariate assessment of the total number of clinical events with housing and management factors by Poisson regression.
Hypotheses (H): positive (+) or negative (-) relationship of each variable with the number of clinical events per animal as a measure of elephant welfare, and whether observed relationships were in the predicted direction (Y yes / N no).
Table 6.
Descriptive statistics (N, mean, standard error of the mean [SEM], minimum and maximum) for significant variables retained in final multivariate models, either for the total number of clinical events per animal (Poisson model), or for the individual number of gastrointestinal, skin lesion, lameness/stiffness and foot lesion event types per animal (binomial and/or Poisson model types).
Table 7.
Univariate analyses investigating relationships between welfare outcomes and the total number of clinical events in African and Asian elephants in North American zoos.
Hypotheses (H): positive (+), negative (-), or neutral (/) relationship of each variable with the number of clinical events as a measure of elephant welfare, and whether observed relationships (P<0.15) were in the predicted direction (Y yes / N no).
Table 8.
Multivariate assessments of the total number of clinical events with the standard deviation1 and the coefficient of variation2 in serum cortisol by Poisson regression.
Hypotheses (H): positive (+) or negative (-) relationship of each variable with the number of clinical events per animal as a measure of elephant welfare, and whether observed relationships were in the predicted direction (Y yes / N no).
Table 9.
Multivariate assessment of the occurrence of gastrointestinal events by binomial regression, counting each animal as having experienced (n = 89) or not (n = 123) this type of pathology.
Hypotheses (H): positive (+) or negative (-) relationship of each variable with the occurrence of clinical events per animal as a measure of elephant welfare, and whether observed relationships were in the predicted direction (Y yes / N no).
Table 10.
Multivariate Poisson regression of factors associated with the number of gastrointestinal events experienced by individual elephants that experienced at least one event (n = 89).
Hypotheses (H): positive (+) or negative (-) relationship of each variable with the number of clinical events per animal as a measure of elephant welfare, and whether observed relationships were in the predicted direction (Y yes / N no).
Table 11.
Multivariate assessment of the occurrence of skin lesions by binomial regression, counting each animal as having experienced (n = 77) or not (n = 135) this type of pathology.
Hypotheses (H): positive (+) or negative (-) relationship of each variable with the occurrence of clinical events per animal as a measure of elephant welfare, and whether observed relationships were in the predicted direction (Y yes / N no).
Table 12.
Multivariate assessment of the occurrence of skin lesions by binomial regression, counting each animal as having experienced (n = 77) or not (n = 135) this type of pathology.
Hypotheses (H): positive (+) or negative (-) relationship of each variable with the occurrence of clinical events per animal as a measure of elephant welfare, and whether observed relationships were in the predicted direction (Y yes / N no).
Table 13.
Multivariate Poisson regression of factors associated with the number of skin lesions experienced by individual elephants that experienced at least one event (n = 77).
Hypotheses (H): positive (+) or negative (-) relationship of each variable with the number of clinical events per animal as a measure of elephant welfare, and whether observed relationships were in the predicted direction (Y yes / N no).
Table 14.
Multivariate assessment of the occurrence of lameness/stiffness by binomial regression, counting each animal as having experienced (n = 80) or not (n = 132) this type of pathology.
Hypotheses (H): positive (+) or negative (-) relationship of each variable with the occurrence of clinical events per animal as a measure of elephant welfare, and whether observed relationships were in the predicted direction (Y yes / N no).
Table 15.
Multivariate Poisson regression of factors associated with the number of lameness/stiffness events experienced by individual elephants that experienced at least one event (n = 80).
Hypotheses (H): positive (+) or negative (-) relationship of each variable with the number of clinical events per animal as a measure of elephant welfare, and whether observed relationships were in the predicted direction (Y yes / N no).
Table 16.
Multivariate assessment of the occurrence of foot lesions by binomial regression, counting each animal as having experienced (n = 61) or not (n = 151) this type of pathology.
Hypotheses (H): positive (+) or negative (-) relationship of each variable with the occurrence of clinical events per animal as a measure of elephant welfare, and whether observed relationships were in the predicted direction (Y yes / N no).
Table 17.
Multivariate Poisson regression of factors associated with the number of foot lesions experienced by individual elephants that experienced at least one event (n = 61).
Hypotheses (H): positive (+) or negative (-) relationship of each variable with the number of clinical events per animal as a measure of elephant welfare, and whether observed relationships were in the predicted direction (Y yes / N no).