Table 1.
Characteristics of the Ugalla USO digging sites
| Site | Site area,* m2 | No. of holes | Maximum diameter, mm | Minimum diameter, mm | Depth, mm | Species† | Tool(s)‡ |
|---|---|---|---|---|---|---|---|
| 1 | 28 | 9 | 226 ± 68 (90–350) | 207 ± 59 (90–300) | 108 ± 47 (50–210) | Dolichus kilimandscharicus | |
| 2 | n/a | 1 | n/m | n/m | n/m | Unidentified | |
| 3 | 7 | 4 | n/m | n/m | n/m | D. kilimandscharicus | |
| 4 | n/a | 1 | 280 | 220 | 180 | Unidentified | |
| 5 | 6 | 4 | 116 ± 42 (60–155) | 66 ± 20 (45–90) | 55 ± 37 (30–110) | Tacca leontopetaloides | IS-S-001, IS-S-002, IS-W-001, IS-W-002 |
| 6 | 12 | 4 | 221 ± 107 (95–320) | 171 ± 84 (65–260) | 151 ± 62 (80–215) | Raphionacme welwitschii | IS-S-003 |
| 7 | 300 | 62 | 146 ± 41 (60–260) | 115 ± 30 (60–200) | 65 ± 29 (30–150) | Brachystegia bussei, Smilax sp. | |
| 8 | 17.5 | 7 | 200 ± 82 (100–300) | 154 ± 70 (50–250) | 127 ± 76 (50–250) | B. bussei | |
| 9 | 142.5 | 30 | 139 ± 52 (70–250) | 110 ± 45 (50–230) | 99 ± 53 (30–200) | B. bussei, Smilax sp. | |
| 10 | n/m | >1 | n/m | n/m | n/m | B. bussei | |
| 11 | 277.5 | 96 | 97 ± 33 (40–180) | 79 ± 27 (35–170) | 81 ± 39 (30–190) | Fadogia quarrei | IS-B-001, IS-B-002 |
Data are ±SD with ranges in parentheses. n/a, not applicable; n/m, not measured.
*Minimum polygon area encompassing all holes identified at a site.
†Although B. bussei does not have USOs sensu stricto, its young roots are used to store nutrients. Only the roots of very young saplings (up to 20 cm high) of this tree species were dug up; these taproots resembled in shape small carrots.
‡See Fig. 2 for an illustrated key to tool specimen catalog numbers.