Table 1.
Summary of population demographics including number of elephants (N) and age distributions (mean, median, SEM, minimum and maximum) for each species by sex and origin.
Table 2.
Description of social life events recorded in studbooks.
Table 3.
Summary of life events and age (as of 7/1/2012) for the full population (n = 250) by species, sex and origin.
Data include the number of elephants that were included in each variable (n), and the number of events, including median, mean (# events/elephant), SEM, minimum and maximum.
Table 4.
Age at separation (median, mean, SEM, minimum and maximum) from mother due to either transfer of individual, transfer of mother, or death of mother for the full population and by species and sex.
Fig 1.
Summary of event frequencies for the study population of African and Asian elephants in North American zoos.
Frequency of number of elephants experiencing (A) Transfers, (B) Offspring births–females, (C) Offspring Deaths–females, (D) Birth exposures–females, (E) Death exposures–females, (F) Death exposures–males, and (G) Birth exposures–males. Bins include no experience/exposure (0 events).
Table 5.
Summary of parameter estimates from Poisson regression models, including beta estimates, standard errors (SE) and corresponding 95% confidence intervals.
p<0.05.
Table 6.
Summary of incident rate ratios (IRR) relative to time using Poisson regression models, including 95% confidence intervals for IRR.
p<0.05. IRR = estimated rate of event experience/exposure.
Table 7.
Summary of age (in years) at first recorded event exposure using Kaplan-Meier analysis including, number of elephants (N) included in the analyses, mean, SEM and median.
Table 8.
Summary of parameter estimates for estimated relative risk (ERR) of exposure to/experiencing the first recorded event using multi-variable Cox regressions, including 95% Wald confidence intervals for ERR.
p<0.05. ERR = estimated relative risk of exposure to/experiencing the first event.
Table 9.
Summary of parameter estimates from negative binomial regression models, including beta estimates, standard errors (SE) and corresponding 95% confidence intervals.
p<0.05.
Table 10.
Summary of incident rate ratios (IRR) relative to time using negative binomial models, including 95% confidence intervals for IRR.
p<0.05. IRR = estimated rate of event experience/exposure