Volume 14, Number 9—September 2008
Research
Forest Fragmentation as Cause of Bacterial Transmission among Nonhuman Primates, Humans, and Livestock, Uganda
, Thomas R. Gillespie, Innocent B. Rwego, Elizabeth L. Estoff, and Colin A. ChapmanTable 1
Characteristics of locations included in the study and sample sizes of households, persons, and Escherichia coli bacterial isolates*
| Location | Characteristics |
Sample sizes† |
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Area‡ | Perimeter‡ | Distance to park‡ | Primate species present§ | Disturbance¶ | Household | Human | Livestock | BWC | RC | RT | ||
| Kibale National Park | 792.73 | 197.20 | 0 | BWC, RC, RT, + 9 others‡ | Low | NA | NA | NA | 10, 35 | 12, 46 | 7, 26 | |
| Bugembe fragment | 0.66 | 1.48 | 1.69 | BWC (11), RC (60), RT (10) | Medium | 8 | 25, 52 | 27, 92 | 11, 42 | 9, 33 | 1, 4 | |
| Kiko 1 fragment | 1.48 | 3.52 | 1.11 | RC (4), RT (7)# | Very high | 13 | 48, 139 | 16, 57 | NA# | 4, 13 | 4, 8 | |
| Rurama fragment | 1.13 | 1.42 | 0.66 | BWC (15), RC (15), RT (12) | High | 7 | 26, 61 | 17, 53 | 13, 48 | 12, 46 | 10, 36 | |
*BWC, black-and-white colobus (Colobus guereza); RC, red colobus (Procolobus rufomitratus); RT, red-tailed guenon (Cercopithecus ascanius); NA, not available.
†Pairs of values indicate sample sizes of individuals and bacterial isolates, respectively. Household numbers indicate sample sizes of households enrolled in the study; approximately twice the indicated number of households are associated with each fragment. Although many households surround Kibale National Park, nonhuman primates were sampled only from core undisturbed forest sites where home ranges do not overlap with human settlements. Livestock included both cattle (Bos indicus and B. taurus x B. indicus crosses) and goats (Caprus hircus), which are combined here and in subsequent analyses because results were essentially identical when the species were analyzed separately.
‡Area (km2) and perimeter (km) were calculated by using the computer program ArcMap, version 9.1 (ESRI, Redlands, CA, USA), from point data gathered by walking the boundary of each fragment with a hand-held global positioning system unit. Distance to the park (km) was calculated as the shortest straight-line distance between the fragment and the park boundary.
§Numbers in parentheses indicate population sizes of each species in each fragment in July 2005. See Struhsaker (21) for a description of the primate fauna and ecology of Kibale National Park.
¶Disturbance rankings are based on quantitative measures of encroachment from Onderdonk and Chapman (11) and from Gillespie and Chapman (12), as well as on qualitative assessments of forest clearing rates and intensities of human activity gathered from ground surveys in 2005–2006.
#BWC had been extirpated from Kiko 1 fragment shortly before this study began, and RC were extirpated from the fragment shortly after sampling was completed, between January and July 2006. A combination of habitat destruction and hunting by domestic dogs led to the local extinctions of these 2 primate species.
