Table 3.
Overview of differences between transects in NDVI and NDBI (calculated from the 40 m buffer), total number of squirrels observed and the relative squirrel abundance during each study period (values are mean ± SD)
| Transect | NDVI | NDBI | Squirrels | Squirrel abundance (individuals/ha) | |||
|---|---|---|---|---|---|---|---|
| July’20 | Sept’20 | Nov’20 | Feb’21 | ||||
| Duke Forest (F) | 0.87 | 0.11 | 102 | 2.12 ± 0.83 | 2.07 ± 0.61 | 0.78 ± 0.35 | 0.31 ± 0.36 |
| Cemetery (CE) | 0.58 | 0.39 | 5 | 0.24 ± 0.47 | 0.24 ± 0.47 | 0.12 ± 0.24 | 0 |
| Duke Chapel Drive (C_C) | 0.53 | 0.41 | 28 | 2.62 ± 1.21 | 1.81 ± 1.38 | 1.21 ± 1.04 | 0 |
| Duke Science Drive (C_S) | 0.45 | 0.47 | 65 | 2.34 ± 1.91 | 1.45 ± 1.52 | 2.79 ± 2.23 | 0.67 ± 0.58 |
| Duke Research Drive (C_R) | 0.30 | 0.62 | 61 | 0 | 2.42 ± 2.08 | 6.85 ± 2.03 | 3.02 ± 2.74 |
| Downtown Durham (DT) | 0.26 | 0.64 | 33 | 0.17 ± 0.34 | 0.95 ± 0.33 | 1.21 ± 0.60 | 0.52 ± 0.45 |