Table 2. Description of variables created from the space and social information on manager’s survey, indicating unit of analysis, unit of measurement, time scale for which each variable was evaluated, and calculation method.
| Variable | Category | Unit of Analysis | Unit* | Time Scale | Description |
|---|---|---|---|---|---|
| Total Exhibit Size | Zoo | (ft2) | Total area of space available to elephants at zoo | ||
| Herd Size | Zoo | Total number of elephants at zoo | |||
| Environment Count | Zoo | Total number of unique spaces into which an exhibit could be configured | |||
| Contact | Environment | Elephant | Overall, Day, Night | Maximum number of unique environments an elephant was housed in | |
| Animal | Elephant | Overall, Day, Night | Maximum number of unique elephants focal animal is in contact with | ||
| Social Group | Elephant | Overall, Day, Night | Maximum number of unique social groups focal animal is part of | ||
| Space Experience | The average weighted (by percent time) size of all environments in which an elephant spent time. | ||||
| Total | Elephant | (ft2) | Overall, Day, Night | For all environment types | |
| Indoor | Elephant | (ft2) | Overall, Day, Night | For indoor environments only | |
| In/Out Choice | Elephant | (ft2) | Overall, Day, Night | For environments where there is a choice of indoors or outdoors | |
| Outdoor | Elephant | (ft2) | Overall, Day, Night | For outdoor environments only | |
| Space Experience by Elephant | Elephant | (ft2) | Overall | The area of all environments in which an elephant spent time, divided by the number of elephants sharing each environment, weighted by the percent time spent in each environment and averaged. | |
| Relative Space Experience Change | Elephant | (Total Day Space Experience—Total Night Space Experience)/(Total Day Space Experience) | |||
| Proportion Space Experienced | Elephant | % | Proportion of Total Overall Space Experience to Total Exhibit Size | ||
| Social Experience | Elephant | Overall, Day, Night | The average weighted (by percent time) size of all social groups in which an elephant spent time. | ||
| Relative Social Experience Change | Elephant | (Total Day Social Experience—Total Night Social Experience)/(Total Day Social Experience) | |||
| Proportion Social Experienced | Elephant | % | Proportion of Overall Social Experience to Herd Size | ||
| Percent Time | Sum of monthly percent time spent in category, averaged over time period | ||||
| Indoor | Elephant | % | Overall, Day, Night | Time spent in indoor environments | |
| In/Out Choice | Elephant | % | Overall, Day, Night | Time spent in environments with an indoor/outdoor choice | |
| Outdoor | Elephant | % | Overall, Day, Night | Time spent in outdoor environments | |
| Soft Substrate | Elephant | % | Overall, Day, Night | Time spent in environment with 100% grass, sand, or rubber substrate | |
| Hard Substrate | Elephant | % | Overall, Day, Night | Time spent in environment with 100% concrete or stone aggregate substrate | |
| Dirt Substrate | Elephant | % | Overall, Day, Night | Time spent in environment with 100% dirt substrate | |
| Juveniles (<7 years old) | Elephant | % | Overall, Day, Night | Time spent in social groups where an elephant 7 years or younger was present | |
| Mixed Sex Groups | Elephant | % | Overall, Day, Night | Time spent in social groups where both males and females were present | |
| Housed Separately | Elephant | % | Overall, Day, Night | Time spent housed alone (Social group of 1) | |
| Housed Separately with Restricted Physical Access | Elephant | % | Overall, Day, Night | Percentage of elephant’s time Housed Separately with contact through a barrier. | |
*Area based variables are presented as ft2 for consistency with companion papers. Metric equivalents are available in (S1 Table).