Table 1. Characteristics of Pteropus giganteus roost trees versus non-roost trees and roost sites versus random comparison sites.
| Variable* | Roost features | Comparison features | P-value† |
|---|---|---|---|
| ROOST TREE CHARACTERISTICS | Roost Trees | Non-Roost Trees | |
| Diameter at breast height (cm) | 53.1 ± 56.6 | 22.3 ± 38.3 | <0.001 |
| Height (m) | 19.9 ± 7.4 | 12.2 ± 6.5 | <0.001 |
| Percentage canopy trees | 88.6 | 20.8 | <0.001 |
|
| |||
| ROOST PLOT CHARACTERISTICS‡ | Roost Plots | ||
| Species richness | 6.4 ± 3.5 | ||
| Percentage canopy cover | 61.0 ± 18.6 | ||
| Percentage roosts with <50% canopy cover | 29.3 | ||
| Mean stand basal area (m-2 / ha) | 140.2 ± 186.7 | ||
|
| |||
| ROOST SITE CHARACTERISTICS (1-km buffer) | Roost Sites (n= 215) | Random Comparison Sites (n = 645) | P-value † |
| Land Cover | |||
| Distance to river (km) | 1.9 ± 1.8 | 2.2 ± 2.4 | 0.06 |
| Percent forest/rural settlement cover | 30.5 ± 16.0 | 31.3 ± 29.2 | 0.60 |
| Forest patch density (patches km-2) | 0.85 ± 0.42 | 0.73 ± 0.49 | 0.001 |
| Forest edge density edge length (m km-2) | 21.5 ± 7.1 | 16.2 ± 10.0 | <0.0001 |
| Largest patch index (%) | 22.4 ± 17.9 | 24.9 ± 28.6 | 0.15 |
| Percent flooded area | 37.8 ± 23.2 | 53.0 ± 30.8 | <0.0001 |
| Average vegetation condition index (%) | 73.0 ± 22.2 | 67.5 ± 24.3 | 0.004 |
| Percent drought area | 14.5 ± 20.7 | 18.5 ± 25.1 | 0.02 |
| Climate | |||
| Annual mean temperature (°C) | 25.5 ± 0.4 | 25.5 ± 0.5 | 0.62 |
| Mean diurnal range (°C) | 9.8 ± 0.6 | 9.6 ± 0.8 | 0.0002 |
| Mean temperature of warmest quarter (°C) | 28.7 ± 0.4 | 28.6 ± 0.6 | 0.001 |
| Mean temperature of coldest quarter (°C) | 19.6 ± 0.7 | 19.9 ± 0.8 | <0.0001 |
| Temperature annual range (°C) | 22.5 ± 1.6 | 21.8 ± 2.1 | <0.0001 |
| Annual precipitation (mm) | 2085.5 ± 432.1 | 2268.4 ± 581.1 | <0.0001 |
| Precipitation of warmest quarter (mm) | 895.0 ± 277.2 | 936.5 ± 300.5 | 0.07 |
| Precipitation of coldest quarter (mm) | 31.9 ± 6.4 | 34.4 ± 7.2 | <0.0001 |
| Elevation (m) | 17.4 ± 9.7 | 26.0 ± 42.4 | <0.0001 |
| Latitude | 24.3 ± 1.1 | 23.8 ± 1.2 | <0.0001 |
| Human disturbance | |||
| Human population density (people km-2) | 1746 ± 3334 | 959 ± 992 | 0.001 |
| Road density (km km-2) | 9.0 ± 3.6 | 6.5 ± 4.3 | <0.0001 |
*
Data presented as means ± 1 SD unless otherwise noted
†
Based on two-tailed, independent groups t-test or χ2 test results
‡
Roost plots were defined as the 20×20 m area around the central roost tree; No comparison plots were evaluated in the field for this study